Solar Energy Facts & Resources Tue, 13 Oct 2015 05:18:00 -0400 en-gb ( Do you need to wash your rooftop solar panels? Do you need to wash your solar panels?

It’s a good question and one with a lot of different answers. Companies specializing in cleaning solar panels generally say: Yes – you have to clean your rooftop solar panels and you have to clean them regularly. Some say panels need an annual scrub, others say quarterly. One company selling an automated washing system says panels should be washed every couple weeks.

]]> (Amanda H. Miller) Solar Energy Resources Thu, 26 Sep 2013 19:47:30 -0400
Understanding solar inverters The solar inverter is like the switchboard operator or middle manager of a photovoltaic array. In a conventional PV system all the PV modules are wired or tied into a central inverter, also called a string inverter.

The inverter itself conducts several important functions. Most importantly it converts the direct current (DC) electricity produced by the photovoltaic modules into alternating current (AC) with the proper voltage that can be used by household appliances.

]]> (Chris Meehan) Solar Energy Resources Tue, 30 Jul 2013 22:56:00 -0400
Why do power optimizers for solar systems matter? Relatively new to the solar marketplace are a new type of technology that helps boost effeciency and hence the output of solar PV systems.  Power optimizers help condition the electricity produced by photovoltaic modules and by wind turbines. They act as sort of a DC to DC converter for each module and use maximum power point tracking (MMPT) technologies. MMPT measures the output of all the cells or PV modules in an array and applies the proper resistance or electric load to produce as much power as possible in an array. As such, power optimizers allow each panel in an array to produce as much power as possible and increase or decrease the module’s output voltage to match the amount of voltage requested by the inverter they’re tied to.

]]> (Chris Meehan) Solar Energy Resources Tue, 02 Jul 2013 16:15:00 -0400
What are SRECs? Solar renewable energy credits, or solar renewable energy certificates, known as SRECs, are tradable energy commodities that represent the environmental benefit of producing one megawatt-hour of electricity using renewable solar technology. 

In the eight SREC states, the Renewable Portfolio Standard requires electricity suppliers to secure a portion of their electricity from solar generators. An SREC can be created for every megawatt-hour of solar electricity created.

An SREC is sold separately from the electricity and represents the “solar” part of the electricity produced. The market- supply and demand- determines the SREC value.

]]> (Kelsey Dayton) Solar Energy Resources Sat, 08 Jun 2013 00:39:26 -0400
What are micro-inverters Solar micro-inverters, like their big brothers string inverters, convert the direct current (DC) electricity that solar panels produce to the alternating current (AC) energy we use to power our electronics. The difference is that they’re smaller.

Instead of converting electricity from an entire solar array or big groups of panels in a solar farm at once, micro-inverters convert DC to AC one or two panels at a time.


Micro-inverters are known to increase solar system efficiency by 5 to 25 percent. The reason is that they are concentrated on one or two panels instead of 100, so they can fine-tune a panel’s output. If there is a problem with one of the panels attached to a string inverter, it can greatly diminish the output of the entire system, depending on the inverter and how it’s configured.

]]> (Amanda H. Miller) Solar Energy Resources Thu, 09 May 2013 17:38:29 -0400
Understanding hybrid PV/thermal systems The sun’s full spectrum of light produces two types of radiation that are useful for energy production. Most solar systems take advantage of one type of radiation, but some newer systems are now taking advantage of both. That’s why there’s an increase in the number of solar hybrid systems now becoming available on the market. They generally produce electricity via photovoltaics and then also solar thermal energy that can be used in other applications, like heating—and yes cooling—a home or building, or for heating a home’s  or building’s hot water. 


In the past however, most solar systems had just been either a solar thermal system or a photovoltaic systems. The former takes advantage of the sun’s thermal or infrared energy, producing heat, which can be harnessed for solar hot water, like the solar thermal panels on rooftops—it can also be reflected and concentrated on a point. This is the type of solar used in most concentrating solar applications, like power towers and trough systems. 

]]> (Chris Meehan) Solar Energy Resources Thu, 09 May 2013 03:06:51 -0400
How Long Is a Standard Solar PV Warranty? Solar WarrantiesSolar installations are investments that deliver increasingly greater returns over time as grid electricity prices continue to rise while free energy from the sun remains a constant.  However, the lifetime ROI of a new installation largely depends on how long that “lifetime” actually is.  Consequently, any homeowner or business owner interested in switching over to solar must understand the actual manufacturing warranties backing whatever systems they explore.  These warranties typically cover the 3 main components of a standard PV installation – the panels, inverters, and batteries if you have them.

Most solar panels come with warranties guaranteeing 80% system performance or higher for 20 to 25 years – well beyond the warrantees typically attached to most electrical appliances, cars, and even diesel generators.  In addition, many manufacturers also segment their warranties, guaranteeing 90% system performance for the first 10 to 12 years.  It’s worth noting that the potential lifetime of a solar PV installation can be as high as 30 to 40 years, with many installations from the 1970s still producing clean energy. 

]]> (Austin) Solar Energy Resources Thu, 20 Sep 2012 21:06:23 -0400
Thin-film photovoltaics flexible solar

Thin-film solar photovoltaics are a class of photovoltaics that are also known as second generation photovoltaics. Thin-film photovoltaics came about as an alternative to silicon-based photovoltaics because the costs of the semiconductors used in thin-films were cheaper than silicon. However, increased production of silicon for solar and other uses has dramatically dropped its cost. That and a subsequent increase in the production of silicon-based photovoltaics have reduced the price of silicon-based photovoltaics, making it harder for thin-film photovoltaics, which are still generally less efficient than silicon photovoltaics. 

There are three main types of thin-film photovoltaics: Cadmium Telluride (CdTe): Copper Indium Gallium Selenide (CIGS); and amorphous silicon. Another type of photovoltaics using Gallium Arsenide could be considered thin-film, but are often called multi-junction photovoltaics since they use multiple layers of semiconductors to absorb more light than other PV cells. For a look at major thin-film producers as of July 2012, see the table at the bottom of the page.

]]> (Chris Meehan) Solar Energy Resources Thu, 05 Jul 2012 00:38:42 -0400
Understanding power purchase agreements power purchase agreementPower-purchase agreements are contracts, under which property owners (hosts) lease power-generating systems, financed by a third party, and use electricity generated by systems onsite.

PPAs are a powerful tool in the solar developer’s arsenal, a financier helps reduce the up-front costs of installing solar on a home or building. In exchange, the property owner—host—enters into a legal contract—essentially an equipment lease—with the installer or a third party (usually an investment firm, a bank, or a community) and pays a set monthly rate for the duration of the contract.

]]> (Chris Meehan) Solar Energy Resources Fri, 01 Oct 2010 18:44:27 -0400
Understanding wind-solar hybrid systems If you’re interested in renewable energy, you’ve probably heard the term wind-solar hybrid before and wondered what that really meant. On the surface, its pretty straight forward; it’s a renewable energy system, generally small, designed to provide power for your home or small business.

But there’s a difficult side to this technology: How do you connect two or more different types of electric current, condition, and convert it into usable, stable electricity for your home or building? And why consider a hybrid system anyhow?

]]> (Chris Meehan) Solar Energy Resources Thu, 30 Sep 2010 15:36:44 -0400
Are solar panels recycled? Solar power modules, much like electronics, contain a variety of potentially hazardous materials, and cannot be safely disposed of in landfills. Solar panels generally function for 20-25 years, so the majority of panels manufactured are still in use. However, in years to come, their disposal could become an issue. New companies like PV Recycling are therefore looking for ways to recycle or reuse these solar modules when they have reached the end of their lifespan.


The solar industry in the United States has been steadily expanding, with 320 megawatts (MW) of system equipment installed in 2008, and a predicted 2,000 MW of panel modules to be installed during 2012. This rate of growth, due in part to the cost of solar power growing more cost-efficient, will put the U.S. solar capacity ahead of industry leaders like Germany, but brings with it more disposal problems. Scrap material, failed panels, and panels broken in transport will be likely to increase as the industry expands. PV Recycling is one of the businesses that have arisen to tackle the problem of how to dispose of this equipment.

]]> (Seth Berger) Solar Energy Resources Thu, 12 Aug 2010 16:45:54 -0400
Do-it-yourself solar generator If you’re looking to save a few dollars each month on your electricity bill, or wish to take on a project that will help the environment, you should consider constructing your own solar power generator. These generators are fairly inexpensive, about $200-$300, and you can easily find all of these parts from electronics and RV/boat supply stores, or on the Internet.

]]> (Seth Berger) Solar Energy Resources Wed, 11 Aug 2010 18:06:36 -0400
How affordable is solar thermal equipment? Solar thermal energy is an environmentally-friendly way to provide heat for your home. Solar thermal systems can use either collection tanks that reflect solar energy into water storage tanks that provide hot tap water, or “solar walls” that warm external building surfaces, and circulate air near those surfaces to heat interior rooms.

While these systems are capable of reducing electrical and gas use substantially, many people do not consider them to be viable options for clean household energy because of their cost. The cost of a complete solar thermal system with two panels usually falls between $8,000 and $10,000. This may seem like a steep price, but if you are going to be living in your home for several years, it may be the cheapest long-term heating solution.

]]> (Seth Berger) Solar Energy Resources Wed, 11 Aug 2010 16:51:39 -0400
Four reasons to go solar now Now more than ever is the best time to install solar power on your home or building. As photovoltaic (PV) and solar thermal technologies continue to grow, the costs associated with installing solar systems continue to drop. At the same time, the prices on your energy bill continue to go up because the prices on coal and natural-gas supplied power continue to increase. There are many other reasons to install solar now, here are just a few:

]]> (Chris Meehan) Solar Energy Resources Wed, 04 Aug 2010 18:32:14 -0400
How heat affects photovoltaics There’s a complex relationship at work between photovoltaics (PV), heat and sunlight. Solar power works best when the sun’s shining (of course). But when the sun’s shining, everything gets hotter.

PV semiconductors offer more resistance in extreme heat, making them less efficient when the modules should be most efficient. Thankfully, this additional resistance is small, at most, reducing efficiency by about 10 percent. But newer technologies—like thin-film PVs, which don’t rely on crystalline silicon to produce electricity—are less susceptible to heat-related efficiency losses.

]]> (Chris Meehan) Solar Energy Resources Wed, 28 Jul 2010 17:38:59 -0400
How long do installations take? Considering installing a photovoltaic (PV) system on your home but are wondering how long it will take? Not long at all!

Most PV systems are installed within a few days of installers starting work. It’s likely to take longer to get the installers there in the first place and to qualify for any solar rebates, credits, or incentives prior to installation of the system. If you’re planning on setting up a net metering system, it may also take the utility company a bit longer to set up a bidirectional electric meter.

]]> (Chris Meehan) Solar Energy Resources Tue, 27 Jul 2010 17:55:23 -0400
Top five U.S. solar cities  The overwhelming majority of the United States gets enough sunlight to make a PV system viable—an average of nearly 5.0 kilowatt hours per square meter daily (kWh/m2/day). But there’s a wide swath of the southwest that looks like a giant fireball on the National Renewable Energy Laboratory’s (NREL’s) map, “Photovoltaic Solar Resources of the United States.” This region gets 6.8 kWh/m2/day or more of solar radiation.

In many of these areas PV is quickly gaining traction and some of the larger cities in the region are capitalizing on it, but other cities could stand to catch up. Local and state incentives can help home and business owners install solar on their home. Since solar installers can add arrays quickly, the leaders are fluid at best.

San Diego, Calif, is an ideal market for PV and the city is capitalizing on it. The city is one of the DOE’s Solar America Cities, and the goal of its “Sustainable Energy 2050 Plan” is to create a local, reliable, and independent energy system that serves as a blueprint for the nation.

San Francisco’s ties to silicon valley have made it a solar leader for a long time. As early as 2001, the city approved a $100 million bond initiative for renewables, Solar Cities America said. The city passed a renewable energy initiative under which 31 MW of PV will be operation by 2012.

Tucson, Ariz. gets some of the nation’s best sunlight. While Tucson is part of the Solar Cities America program, it’s ripe for more solar development. Indeed, the program notes that the Tucson Solar Initiative is now focused on working “to overcome the market barriers of high up-front cost and low levels of awareness.”

Flagstaff, Ariz. has 288 days of sunshine a year, but NREL’s OpenPV project said that at this point it has only 246 kilowatts of PV installed.

Pueblo, Colo. in southern part of the state, has about 330 days of sun a year but only has about 6 kilowatts of PV installed, OpenPV shows. That low number may change soon. The city’s constructing a new PV-powered waste-water plant. And its economy is being revitalized with a Vestas wind-turbine manufacturing plant.


]]> (Chris Meehan) Solar Energy Resources Fri, 23 Jul 2010 16:48:59 -0400
Do you live in a green state? States with solarIn this time of oil spills and global warming, polar cap melting and Prius-buying, the hottest word out there today is that environmentally friendly color: green.
“Being green” refers to reducing damage to the environment and trying to help protect nature’s assets. When it comes to states though, being green takes a lot.

It means having low per-capita emissions, good recycling programs, significant energy usage coming from renewable sources, and clean energy incentives or tax credits for doing things like composting or installing solar panels.

Solar Energy Resources Fri, 23 Jul 2010 15:50:06 -0400
Do-it-yourself solar panels By doing a few key things, you can make a photovoltaic panel for significantly less than you’d pay for a newly manufactured PV panel. Manufacturers and distributors of PV equipment sell damaged or blemished PV cells cheap. Connecting and mounting them in a series allows you to make a working PV panel that you can be used to power appliances or other equipment in your home.

The first step in building your own PV panel is to determine how powerful the panel you want to make will be. Next, find PV cells that will produce that much power. Contact manufacturers to see if they will sell you damaged cells directly, or go to e-Bay and search for damaged PV cells. They’re usually offered in stacks or bricks. Mike Davis, who has detailed instructions for building a PV panel at his web site,, recommended that you find PV cells prewired with tabs to help minimize soldering.

After you get your PV cells, you need to design a box to house them in—the lighter the better. You can build a box out of plywood with extra venting as Davis does. Or you sandwich PV cells between layers of Plexiglass. Davis’ method leads to a much heavier, but vented PV panel to ensure that moisture will not collect in the panel and damage the cells. If you choose to make a lighter panel by sandwiching the cells between two layers of Plexiglass, use silicone glue or weather stripping to make sure moisture can’t enter into the panel.

Draw out how your PV cells will be arranged on the base of the panel. This will make it easier to mount them later. Now you can start soldering the individual PV cells together. Handle them carefully—they are fragile and brittle. On the back of each cell, there should be a number of positive contacts. Solder the tabs from the next cell—which connect to the negative anodes on its surface—to the positive contacts. Do this with each cell to create a row of cells.

Place a small spot of silicone glue in the center of each cell and then place the row onto the panel’s surface. Press each cell down lightly to allow for some growth and shrinkage. Repeat with each string of connected cells.

Run a wire across the top of the panel, soldering it to the negative contacts on each cell. At the bottom of the panel, solder a wire to each positive contact. Connect the positive and negative wires to insulated wires that will be used to hook the panel up to an appliance, inverter or charge controller. Run a bead of silicone caulk around the base of your panel, then place the top cover over it, and you have your own, homemade, PV panel.

]]> (Chris Meehan) Solar Energy Resources Wed, 21 Jul 2010 17:44:03 -0400
Understanding How Photovoltaics Work  More and more we’re looking to photovoltaics (PV) and renewable energy to supply our future energy needs. Some science behind PVs is well over a century old—Albert Einstein’s 1905 explanation of the photoelectric effect won the Nobel prize in physics in 1921.

PVs absorb sunlight and convert it into electricity through a nonmechanical process. The PV cell’s materials are able to absorb photons from at least part of the sun’s electromagnetic radiation. Traditionally, PVs have used treated silicon as a semiconductor in both the n-type and p-type layers of PV cell, which allow for the flow of electrons.

]]> (Chris Meehan) Solar Energy Resources Wed, 14 Jul 2010 16:53:43 -0400
Understanding Concentrated Solar Power Systems Concentrated solar power is one of the hot new ways (literally!) that energy companies and homeowners are looking to generate cheap, plentiful sources of renewable energy. For instance, the Odeillo-Font-Romeau Solar Furnace in France melts iron ore into steel. The structure uses 63 heilostatic (sun-tracking) mirrors that concentrate light on a large reflector. The reflector focuses all the light on a crucible which reaches 3,500 degrees Celsius.

The first large-scale solar thermal power plant—using parabolic troughs—was built in 1985 (it’s still active today), but newer methods of concentrating solar power (CSP) have created power towers, which are capable of powering thousands of homes. Looking like a giant metallic flower or a satellite dish, power towers have a central tower surrounded by a massive field of heliostats. The heliostats focus all the sunlight hitting them throughout the day on the central tower. That concentrated sunlight superheats the tower and can reach temperatures like the Solar Furnace does.

]]> (Chris Meehan) Solar Energy Resources Tue, 13 Jul 2010 18:38:57 -0400
Understanding Solar Thermal Energy Solar thermal energy is the collection of the sun’s heat for human use. It’s unlike photovoltaic (PV) power, which converts a portion of the sun’s electromagnetic radiation directly to electrons and electricity. Solar thermal has a broader range of uses than PV does, since the sun’s heat can be collected and transferred in a medium, and that stored energy is then used for purposes including heating and cooling a home, heating water, cooking food, or creating electricity. The first two uses are generally suitable for homes, as is generating electricity, but the latter is usually done on the commercial scale.

Three ranges of solar thermal energy are used: low-temperature, which is used for heating cooling and ventilation; mid-temperature, which is used for cooking, hot-water heating, and other purposes in the mid-heat range; and high-temperature, which includes generating electricity. Within the broader spectrum of generating electricity, there are various means of focusing the sun’s heat to create electricity through a heat exchanger that superheats water or an inert gas to power a electricity-generating turbine, or a Stirling engine to produce electricity.

The first large-scale solar thermal electricity generators used a mirror-faced reflective parabolic trough to concentrate solar energy on a tube filled with a liquid like antifreeze, water, or synthetic oil. The trough reflects the sun’s heat back onto the tube and heats the liquid inside the tubes. The heated liquid is cycled through to a heat exchanger. There the hot liquid turns water into pressurized steam which pushes a turbine, producing electricity.

To maximize their output, the tubes are surrounded by evacuated glass tubes, which helps them absorb more heat energy and keeps them from reradiating the heat energy. The troughs usually are oriented north to south and follow the sun’s travels throughout the day. To maximize the amount of electricity such a system produces, excess heat is stored in super-insulated tanks filled with molten salt or graphite (both are excellent at retaining heat) and then used to keep the turbines running throughout the night.

The largest solar power plant in the world, PV or otherwise is the Solar Energy Generating System (SEGS) in California. Nine solar thermal plants make up SEGS and have a total capacity of 350MW, enough to power about 105,000 homes. Though they make up the world’s largest solar power plant, parabolic trough systems are available for rooftop installations, in 4- or 8-foot-wide units. The National Renewable Energy Laboratory’s solar resource maps or your local installer will help you decide if you’re in a good place for solar thermal power.

]]> (Chris Meehan) Solar Energy Resources Tue, 13 Jul 2010 18:33:30 -0400
Understanding Solar Hot Water You could likely use the sun to provide most or all of your home’s hot water needs cost-effectively. In fact, nearly 50 percent of homes in the United States could take advantage of a solar hot-water system. In its essence, solar hot-water heating is achieved by heating a series of tubes filled either with water or another liquid that is transferred to a storage tank for use. According to DOE’s EnergySavers site, “On average, if you install a solar water heater, your water heating bills should drop 50–80 percent.”

The first solar hot-water heaters for homes in the United States started appearing on rooftops in the 1970s when federal and state incentives existed. But shortly after the incentives dried up, the panels stopped appearing.

Panels in the 1970s were called bread boxes. They were thick boxes covered with glass or Plexiglass with wide tubes inside. The tubes were used both to store water and heat it. To reduce heat loss, the box was insulated on all sides. However, the breadboxes had limited surface capacity to absorb solar heat, reducing their efficiency.

There are two main types of modern solar hot water heating systems. Both heat liquid within the tubes and transfer it to a thermal storage tank in the home. Flat-panel hot water heaters are best at capturing direct sunlight, but evacuated-tube water heaters are better at collecting heat during cool or cloudy days.

Flat-panel collectors are based on the breadboxes of the 70s but are much thinner, more efficient, and lightweight. These collectors are filled with tubes about one centimeter in diameter, allowing for increased surface for the sun to hit the tubes, making them much more efficient.

The other form uses evacuated-glass tubes, with smaller glass tubes inside painted with a thermal coating. The vacuum between the tubes allows solar radiation in to heat the water but minimizes the loss of heat. Liquid-filled tubes inside the glass tubes are often attached to black metal fins. The fins are usually tinted black to absorb as much sunlight as possible.

Both these new technologies qualify for federal incentives as well as state incentives. Clean Energy Authority has information available about what incentives are available in your state. And a qualified installer can help you determine which are better for your home.

]]> (Chris Meehan) Solar Energy Resources Mon, 12 Jul 2010 21:04:16 -0400
Top ten solar states Many detractors of solar energy will claim that solar is impractical outside of desert landscapes that receive uninterrupted sunshine. And while sun-kissed locations still top this list of top ten states for solar, the high ranking of states New Jersey proves that solar is a viable energy source even in locations where the weather is uncooperative.

“The success of solar seems to depend more on the cooperation and backing of local governments and businesses than on actual sunshine,” observes Waylon Lewis, owner of a home solar installation in Colorado, one of the top ranking states.

Solar Energy Resources Fri, 09 Jul 2010 19:18:14 -0400
Used solar equipment  Purchasing used solar panels can be a great way to save money when installing a solar system in your home or business. The life span of a solar panel is currently unknown—many of the first solar panels are still in operation. But most experts believe that quality solar panels will last more than 80 years. Additionally, recycling old photovoltaic cells will keep their valuable parts and resources from wasting away in landfills—an added environmental bonus.

Although older photovoltaics are still functional, newer panels are technologically advanced and often more efficient. Newer panels produce more wattage with less surface area, so if you have a limited amount of space, it may be wise to spring for a newer model. It can also be difficult to combine many different types of used panels into a large solar array—so be sure that you are dealing with a seller that can provide enough panels of the same type to suit your needs. Panels built before 2005 are often inefficient in shaded areas, a problem that can be addressed by situating older panels in locations that are unobstructed by vegetation or buildings.

Don’t shy away from damaged solar panels. They can be easily and cheaply fixed by a trained professional. Cracked glass, broken frames, condensation under the glass and broken or loose connections are common problems that can often be repaired. Some panels gain a brown tint with age, a condition that does not affect their power-producing ability.

Although there are many websites that offer used solar panels, it is important to test the voltage of used panels, in-person if possible. Be sure to bring along a voltmeter to test the circuit of each panel before purchase. Apply the leads of the voltmeter to the positive and negative ends of the photovoltaic terminal. The meter should read close to 12 volts on a healthy 12 volt panel. Panels that are designed to function in a set of 4 should read between 4 and 5 volts each.

Any way you look at it, finding a cheap solar alternative saves you money and allows you to take advantage of your state's solar incentives and rebates.

Solar Energy Resources Fri, 09 Jul 2010 17:52:05 -0400
Top ten photovoltaic plants in the world The world’s largest installed photovoltaic (PV) farms are powering tens of thousands of homes—mostly in Spain and Germany. The increase in the speed of installation and the size of PV installations is astounding. The largest PV installation just three years ago was about 20 megawatts (MW); today’s largest PV plant is three times bigger. And PV plants now being built in the United States and around the world—including Southern California Edison’s 250 MW warehouse farm—will dwarf today’s operating PV power plants.

]]> (Chris Meehan) Solar Energy Resources Fri, 02 Jul 2010 20:17:33 -0400
Make Your House Energy Efficient So you’re ready to install a photovoltaic system; that’s great. Hopefully, you’ve found all the available state incentives, and a reliable installer for your system. It’s still an expensive investment with a high up-front cost that might make you balk. However, there are many steps you can take to reduce the size of the solar-power system you need by nearly 50 percent, at the same time reducing costs of your photovoltaic installation. These steps range from simple and inexpensive efforts to more expensive, but all are intended to reduce your energy use and make your home a better place.

Perhaps one of the easiest ways to find out how to invest your energy-efficiency dollars is to pay a professional home energy auditor to review how efficiently your home uses energy. The audit, which may cost $600—though some cities, towns, or utilities may help subsidize the cost—will let you know if you have any leaks in your building, how to fix leakage problems, and whether you should consider buying updated appliances and more. Energy auditors use tools like infrared scanners to see where your home has energy leaks (see picture, above) If you choose to have a professional home energy auditor review your home, make sure he or she is certified by an accrediting organization like BPI or RESNET, and ask for references.

If you don’t want to pay a contractor $300 to $600 to perform a home-energy audit, you can do one yourself. The first thing you need to do is evaluate how much energy your home uses on an annual basis. Tally your electric bills for the past year or two and use those figures to determine how much power you use on a monthly basis. This will help you decide how large a photovoltaic system your home needs, as is, but will also help you understand whether or not your home is efficient, and it’s likely that it’s not.

The Simple Steps

The best way to reduce energy use is to start simple! And I mean simple. Make a habit of turning off the lights when you leave the room (unless of course someone else is in there). Put your phantom energy-eating electronics on a diet by turning off power strips when the TV, DVD, game system, or stereo isn’t on. Or get smart power strips, which turn all power off to certain devices when a master device is turned off. This sounds small, but it can have a big impact on your monthly bill.

The next step is lighting. If you haven’t done it yet, get rid of those old, wasteful incandescent light bulbs. Approximately 11 percent of a home’s energy bill is spent on lighting when using incandescent bulbs. Each compact fluorescent light bulb (CFL) uses about 75 percent less energy than an incandescent bulb. It saves about $30 over its lifetime and it pays for itself in just half a year according to Energy Star. So replacing 20 incandescent light bulbs with CFLs could save you about $600. And since they last much longer than incandescent bulbs, you don’t have to replace them as often.

From here, things get a little more difficult. The next step is to find and seal all air leaks in your home. This may be a job for a contractor, unless you have a background in construction or remodeling.

The Department of Energy’s (DOE’s) Energy Efficiency and Renewable Energy (EERE) office said that air-sealing your home can save you between five and 30 percent of your heating and cooling costs. This means finding and sealing drafts and air leaks around electric outlets, pipes, switch plates, window frames, outdoor walls, and the building foundation. It also means making sure you’ve sealed any areas between baseboards and floors, ceilings and attic hatches. A good way to find the leaks is to turn off any appliances that cause air to move in the house (exhaust fans, water heater, other fans, ect.) then use the smoke from a piece of lit incense, a candle’s flame or a damp hand to show you where any leaks are.

Taking these three, inexpensive initial steps can help you save up to 35 percent of your home’s energy costs, helping reduce the size of a photovoltaic system by a similar amount.

Not Enough? Replace Inefficient Appliances

At this point, you may want to consider replacing outdated appliances with newer Energy Star models. An Energy Star refrigerator can cut your energy bill by $200 or more annually, compared to one manufactured prior to 1992 (when Energy Star products entered the market). Other Energy Star-labeled electronics can also help reduce your energy usage significantly. Some Energy Star office products, like computers, fax machines, and printers, can use 90 percent less energy than similar equipment without the label according to Energy Star.

Don’t throw the old blender or toaster out for a new one if you don’t use it that much; make wise choices based on use and energy consumption. Rather, use a nifty device like the Kill-A-Watt EZ, which you plug in between an appliance and the outlet. The device tells you how much energy the device uses and how much it costs you to run it. If you compare the cost of operating the outdated device with what an Energy Star replacement would cost and find that it’s more expensive to keep using the old device—or if you just can’t stand having a split-pea soup-colored toaster—replace it. If not, don’t. The point is; by making wise investments here, you could reduce future energy use significantly.

Reduce Heating and Cooling Costs in Your Home

More than 50 percent of the average home’s energy use goes to heating and cooling, according to the EERE. The next steps in making your home more energy-efficient and to make the transition to photovoltaics or wind power easier are related to reducing heating and cooling costs.

To further reduce your energy use, make sure your home is properly insulated. Many U.S. homes were built when energy costs were low and insulation wasn’t a primary concern. But a well-insulated home will help keep you cool in the summer and warm in the winter. To find out if your home’s insulation stacks up, use the DOE’s ZIP Code Insulation Program. Simply enter your ZIP code and the program will tell you how high an R-value (a measurement of insulations’ properties) and where your home needs insulation to reduce heating and cooling needs.

This also is a good time to consider replacing outdated heating and cooling units. According to EERE, most older systems were oversized because homes lacked sufficient insulation, and while they could cool a home in a snap, they couldn’t dehumidify the air, leaving people in the home building with a clammy feeling. Look for an Energy Star unit and review its Energy Guide label to determine how much it can save you compared to your current system. EERE recommended that homeowners get at least three estimates from licensed HVAC professionals. Ask them whether the air-sealing and insulation projects you’ve undertaken will allow you to reduce the size of a heating and/or cooling unit. A smaller, more efficient unit will cost less than a larger unit and use less energy to regulate your home’s temperature.

Consider replacing outdated windows and doors. Hollow-core wood and steel doors offer very little in terms of insulation. Similarly, older single-paned and even some double-paned windows offer little in terms of insulation. Newer, argon- or other gas-filled double- and triple-paned windows are designed specifically to keep the heat and cold out, and the cool or warm air in.

Altogether, taking these steps can help you reduce your energy use by about 50 percent over what your home previously used or what comparable homes use. Thereby reducing the size of a photovoltaic installation by a similar amount.


]]> (Chris Meehan) Solar Energy Resources Tue, 29 Jun 2010 18:45:24 -0400
Solar vs. Wind: What's best for your location? Want to go renewable, but don’t know whether to go wind or solar? Just like in real estate, the most important thing to consider is location, location, location. But there are many other things to consider too. 

The first thing you need to do is take stock of what resources you have. Throughout most of the United States there is enough sunlight to make a photovoltaic system (PV) a viable option for your location. While residential wind turbines are installed in almost every state, the American Wind Energy Association (AWEA) recommended an average wind speed of four meters per second (about nine miles per hour) to make a wind turbine worthwhile.

As shown in NREL’s Solar Maps, the southwestern parts of the United States get the most sunlight annually, enough to provide more than 6.8 kilowatts hours per square meter (kWh/m2) on the average day. Even Maine receives an average of 4.0 kWh/m2 a day, enough for a PV installation. But a PV system in Maine would need to be larger than a PV system in Arizona to provide enough power for your home or building. And during the winter months in Maine, such a system would need significant battery storage, a backup generator, or need to be tied to the grid.

To determine what size a PV system you would need to offset or completely eliminate your need for grid-supplied power, you can use a solar estimator tool, like NREL’s In My Backyard Estimator or Solar Estimator’s tool. While these will help you get a ballpark estimate of whether or not to consider solar power for your location, a solar professional can help you understand what your solar resources are, how much a PV system will cost, how long it will last, and how much power it will produce at your location.

The majority of suitable locations for wind in the United States are in the Great Plains and along the eastern and western coasts. EERE’s Wind Powering America page can help you determine if your location is suitable for wind power.

To get the most out of a solar installation, you need to have a site that gets a lot of sun from the south, according to the Department of Energy’s (DOE’s) Energy Efficiency & Renewable Energy (EERE) program, you can orient PV panels up to 45 degrees east or west of south with little effect to their ability to produce electricity. However, they need to be tilted appropriately (at least 5 degrees, it differs based on your location) to get the most out of the sun.

A wind turbine requires a significant amount of land. Both EERE and AWEA recommend at least one acre of land for a wind turbine. Also, a turbine needs to be at least 35 feet high, or a good bit taller than any trees or buildings near it. Otherwise it won’t get the full power of the wind. And the higher you go, the windier it gets.

Another important question is, does your power system produce power when you need it most? Wind is most plentiful at night, when power consumption is down. Photovoltaics, on the other hand, produce power during the day, when more electricity is consumed and needed.

Since PV panels come in many forms—some can blend in with tar shingles and even spanish roof tiles—there are a lot of options to meet your needs. And if you’re in a persnickety neighborhood with a homeowners association, they’re more likely to protest a 40-foot tower in the middle of the neighborhood than solar panels on your roof that they likely can’t even see. You can also add more power to a PV system by adding panels with more ease than upgrading a wind turbine, which at the very least would require taking down its tower and changing out the turbine’s gearing and generator.

While both are good choices for powering your home or building, PV offers more flexibility than wind does to meet your needs. Wind may be more suitable if you live in a rural area with good wind potential, but the ability to install solar panels on a roof or in a field means you can put them just about anywhere (as long as they get good southern exposure).

]]> (Chris Meehan) Solar Energy Resources Mon, 28 Jun 2010 15:44:42 -0400
Understanding Distributed Generation and the Role of Photovoltaics As the photovoltaics industry grows, one of the most important ways to offer incentives to residential and commercial building owners for installing photovoltaics is by creating policies that require utilities to buy a certain amount of electricity from these independent entities. Such small-scale distributed generation (DG) also helps create local jobs installing solar, wind, geothermal, microhydro and other forms of renewable energy where they’re needed, instead of just in one centralized area, as is done with large-scale power plants.

The Institute for Local Self-Reliance explains the growing interest in distributed generation in the following way: “In the early 20th century electricity generation and transmission technologies supported the idea that ‘big is better.’” Ostensibly, regulatory rules then encourage building large, centralized power plants with long, expensive distribution lines.

However, according to the institute, “in the 1990s, the technological dynamic was reversed.” During that period, smaller power plants located where customers use electricity became more competitive. At the same time, many local governments and the U.S. Congress have been “rewriting the rules that govern our electricity system,” according to the Institute. It added that the new and changing rules, “will encourage electricity customers to also become electricity producers.”

Distributed generation also bookends nicely with net-metering laws that many states have passed. Net metering requires utilities to pay for power generated by homes or buildings. While net metering laws assure that small, independent electricity producers are paid a fair, state-established price for energy they supply to the grid, small-scale distributed generation laws make sure that utilities will make that purchase the power generated by a buildings’ photovoltaic panels or other renewable power in the first place.

Net-metering laws often mean that utilities have to pay these small-scale distributed generation sites more than they do to wholesale electric producers. In many cases, utilities pay the small power producer at the same rate that the average consumer buys electricity from the utility. And since the owner of the structure is no longer a customer or his need for electricity is reduced, it might seem like a huge loss for the utility to purchase any power generated by small-scale producers.

The benefits of small-scale distributed generation, however, make up for the losses experienced by utilities in other ways. For instance, since distributed generation produces electricity where it’s needed; it helps to reduce the electric load on transmission lines and helps reduce the need for costly new transmission lines associated with new power plants, and solar or wind farms far from towns and cities.

Pace Law School’s Energy and Climate Center issued a recent report, Capturing the Value of Distributed Generation for More Effective Policymaking, explaining how, despite shortfalls, small-scale distributed generation is actually worthwhile and not as costly as previously thought. “In particular, because PV [i.e. photovoltaics] has the effect of reducing demand at opportune times, it helps avoid the cost of running more expensive plants during peak loads,” according to the report.

Distributed generation does this in a number of ways. The report observed that “DG can reduce or eliminate the need for new transmission and distribution capacity upgrades and new generation. DG facilities that correlate to peak periods of demand help to improve the reliability of the grid by freeing up generation capacity and easing bottlenecks, line congestion and harmonic disruptions.” The report added that case studies of small-scale distributed generation have proven, particularly where “optimization analyses are undertaken,” that such results are achievable.

Small-scale distributed generation also helps reduce costs for utilities during peak production hours, i.e. daytime hours, particularly in the summer. This is particularly relevant for photovoltaic and other solar-powered systems, which are most productive during peak consumption hours. By relying on these small-scale electric providers to offset peak power needs, utilities don’t have to rely “on expensive peak generating plants and central power generation at times of day when fuel costs are highest, magnifying the benefits of net metered solar installations,” the Pace report explained.

Distributed generation also leads to energy savings because the power is used where it’s produced, not far away. That means there’s less energy lost in the transmission of electricity from point of production to point of use. “DG reduces the amount of electricity needed from central power generation plants, ultimately leading to fuel savings, operation and maintenance savings and avoided energy purchases by the utility,” said the Pace report. In fact, it concluded that distributed generation can delay or eliminate the need to build or upgrade power plants. And distributed generation could also help reduce the size of needed additions.

Ultimately, the Pace report recommended that “Policymakers should strive to maximize the benefits (including societal benefits) for all stakeholders. Policies could be implemented, for example, that would require DG assessments before authorizing a utility to receive funding for major T&D upgrades. When regulators choose between approving significant rate hikes to pay for upgrades, or adopting customer-owned generation programs that reduce load and congestion, they will likely find the latter more palatable.”

]]> (Chris Meehan) Solar Energy Resources Thu, 24 Jun 2010 20:05:06 -0400
How Solar Panels are Manufactured Hotter than a Wal-Mart parking lot in July, more energy than a caffeinated day care center, and bigger than any Las Vegas buffet, it’s the Sun! Burning at an astonishing 27 million degrees Fahrenheit, the Sun is half the equation to what makes life possible on planet Earth. But, in our ever-evolving world, not only is the Sun necessary for life, it is becoming a key component to making life better. Solar energy is quickly becoming the newest solution to our energy needs without making such a deep carbon footprint. The production, sales, and installation of solar panels have never been greater, but how does a solar panel go from the factory to your rooftop?

The solar panel production process has become almost fully automated. The raw silicon material, which is the primary element used in solar cells, is harvested from the Earth using mechanized mining techniques. Thanks to advances in mining technology, the harvesting process has a relatively low environmental impact. The raw silicon is then shipped to the production line where the next step in production takes place.

Silicon can be distilled into a gas, which is exactly the process used to transform the raw silicon gas into a high purity polysilicon solid. The polysilicon is then moved to a furnace where it can be melted into uniform cubes called ingots. Ingots are essentially giant polysilicon blocks that are cut into several smaller blocks, and then cut again into thin, individual wafers using a wire slicer that can produce many wafers at a time. The next step is where electricity starts coming into play.

A PN (positive negative) junction is formed between a “p” type silicon wafer and an “n” type silicon wafer. The way this type of cell works is by putting the positive and negative cells in close contact with each other and applying an electrical field near the top surface of the whole cell. Now it becomes a Photovoltaic (PV) cell that can generate electric momentum and direction for electrons when the sun hits its surface. This means that the photons from the sun hit the surface of the PV cell and generate electrons that can be collected and forced to flow through an electrical contact such as a wire and power anything from a lamp to a computer. But, we’re not done yet.

After the PN junction is formed and the PV cell is activated, an anti-reflective coating is applied to the cell so that more sunlight is captured, increasing efficiency and reducing the amount of sunlight that might otherwise bounce off the cell without ever being captured and turned into energy. But, as mentioned earlier, to collect all of that precious clean energy, a screen of electrical contacts has to be imprinted on the surface of every cell. Now that the cell has its electrical contacts it’s time to assemble it all together.

Modular assembly is fairly simple. Each individual cell is interconnected by automated soldering machines producing solar cell strings. These strings are the familiar checkerboard pattern that most modules resemble. Once the strings are made, they are put in the middle of a solar sandwich in the following order: glass, EVA film (ethylene-vinylacetate copolymer), the solar cell itself, more EVA film, and finally another pane of glass. This whole thing is then moved into a laminator and laminated in a vacuum, and then packaged in a protective aluminum frame. The solar panel is then shipped from the factory all over the world for all kinds of different applications, including saving you a bundle on energy bills. In fact, if you get enough solar panels installed, you can sell your excess energy back to the energy company and make money, so go out and get some clean, environmentally friendly solar panels!

]]> (AJ Register) Solar Energy Resources Thu, 24 Jun 2010 19:20:44 -0400
What is a Megawatt and a Megawatt-Hour? A megawatt is a unit for measuring power that is equivalent to one million watts.  One megawatt is equivalent to the energy produced by 10 automobile engines.

A megawatt hour (Mwh)  is equal to 1,000 Kilowatt hours (Kwh).  It is equal to 1,000 kilowatts of electricity used continuously for one hour.  It is about equivalent to the amount of electricity used by about 330 homes during one hour.


Solar Energy Resources Tue, 04 May 2010 18:33:52 -0400
What is Net Metering? Net metering is the tool that makes rooftop solar viable for so many Americans. Most states have net metering laws requiring utility companies to buy excess power generated from rooftop solar panels from the homeowners who installed them. That means homeowners can produce more power than they need during the day and sell it back to the utility to offset their electric bills for the power they use at night when the sun isn’t shining.

What states have net metering?

There are 43 states with net metering laws and there are utilities in parts of three of the states without laws that offer net metering programs even though the state doesn’t require it.

Those states without any net metering are: Mississippi, South Dakota and Tennessee.

How much do utility companies pay net metering customers?

Most states require utility companies to credit net metering customers at the retail rate so that every kilowatt hour of power homeowners send back to the grid earns them a kilowatt hour they can take from the grid.

Some states only require utilities to pay net metering customers the avoided cost rate, which is the wholesale price or the cost of running utility generation systems to generate a kilowatt hour of electricity. In that case, net metering customers who send power back to the grid will only be credited about a third of the cost to buy a kilowatt hour of power from the grid.

Some states require utilities to pay customers at the end of the month or at the end of the year for unspent utility credits from net metering. But most states allow the utility to keep any excess power home and business owners don’t use from their rooftop solar systems.


Net metering has come under a lot of fire lately. The Edison Electric Institute, a trade group for publicly-traded utility companies, published a report in 2013 calling net metering a major “threat” to the utility business model. As a result, utilities in several states have proposed legislation to limit or reduce net metering benefits.

The utilities argue that as net metering becomes more common, it will shift the expense of infrastructure investments to those customers who don’t have rooftop solar installations.

The solar industry counters that distributed solar generation saves utilities from having to invest in new infrastructure because the home and business owners are adding new generation capacity without increasing the need for transmission infrastructure.

The controversy has boiled over in Arizona, where debates between Arizona Public Service, the state’s largest utility, and solar advocates has become wildly contentious.

How is net metering evolving

In states like California, Hawaii and Massachusetts where the solar industry is strongest, utilities have started to hit net metering caps. That has forced those states to find ways to allow home and business owners to continue to install grid-connected rooftop solar systems. Legislators and regulators in those states are still grappling with the issue, but are working to balance a need and desire for increased distributed solar generation with reduced benefits to solar customers in order to offset the risk to utilities.

Those states are the pioneers and will serve as an example for those that follow.

Solar Energy Resources Tue, 04 May 2010 17:47:23 -0400
How Much Money Will a Solar Power System Save Me? A solar power system system can save you money.  Your entire electric bill could be saved each month depending on how much electricity you use, the cost of electricity in your area and the capacity of the system you installed.  To calculate specific monthly savings, a site analysis by a local solar installer would be required. 

There are also online calculators such as the PV Watts Calculator from the National Renewable Energy Laboratory (NREL).  According to the NREL website, “The PVWatts calculator works by creating hour by hour performance simulations that provide estimated monthly and annual energy production in kilowatts and energy value.”  Users can select a location and choose to use default values or their own system parameters.  Users can select a location from a map or text list or select any location in the U.S. to determine the energy production and cost savings of grid-connected photovoltaic systems.

Solar Energy Resources Tue, 04 May 2010 17:40:26 -0400
What is a Solar Easement?  When considering solar installation, property owners should consider future obstruction of sunlight to their site.  In most cases, existing zoning regulations will provide the property owner with knowledge of any potential issues with sunlight access.  However, zoning restrictions may not always be enough to protect a solar project’s future access to direct sunlight.  If this is the case, a solar easement may be created between adjoining properties.  Solar easements are permitted in most states.  Property owners with solar systems already in place can negotiate with neighbors and create a solar easement to prevent future shading.

A solar easement is defined by Wikpedia as “a right, expressed as an easement, restriction, covenant, or condition contained in any deed, contract, or other written instrument executed by or on behalf of any landowner for the purpose of assuring adequate access to direct sunlight for solar energy systems.” 

Wikpedia also states: A typical solar easement establishes certain land use conditions agreed upon by the property owners involved.  Such agreements will normally contain the following elements:

  • A description of the dimensions of the easement, including vertical and horizontal angles measured in the degrees or the hours of the day, on specified dates, during which direct sunlight to a specified surface or structural design feature may not be obstructed.
  • Restrictions placed upon vegetation, structures and other objects which may impair or obstruct the passage of sunlight through the easement.
  • The terms and conditions, if any, under which the easement may be revised or terminated
Solar Energy Resources Tue, 20 Apr 2010 16:17:22 -0400
Green Home Building Choices The New Green Building Economy

Just as the housing sector did after 9/11, green-building is poised to become the new engine of the U.S. economy. By improving the infrastructure of many buildings through enormous energy resource savings, creating tens of thousands of jobs, stimulating consumer spending, and improving the environment in numerous ways, green-building projects could propel the U.S. into a new era of growth. Along the way, we have the potential to benefit from:

  • Reducing waste streams
  • Conserving and restoring natural resources
  • Reducing operating costs
  • Optimize long-term investment costs
  • Minimize need for local infrastructure



Why Build Green?
The E.P.A. says that in 2005, buildings, like offices and public buildings, as well as housing and commercial properties, used as much as 39% of the total energy use nationwide and used as much as 69% of the total electricity consumption. In each case, residential housing accounted for more than half on this consumption. In their annual review published in 2008, The Department of Energy expected the number for total energy use nationwide to rise to 75% by 2025. In addition, in the Energy Information Administration Report published in 2008, contends that buildings in the United States contribute as much as 38.9% of the nation’s total carbon dioxide emissions with nearly a quarter of the number attributed to residential housing.

Making Green Building Choices
The only way to ensure that you know what’s going on and understand the choices you have is to find valuable and trusted resources. Many of the recent federal green-building initiatives actually get implemented at the state and local levels. The best way to learn about these is to determine what kind of building type you have and to decide what kind of green-building initiative you wish to implement.   Browsing our  extensive Incentives and Rebates section is a good place to start as it is state green-building-initiative-specific. For example, under the state of  Florida, a program like the Florida Renewable Energy Property Tax Exemption  is easy to understand and use.

Having questions answered by industry experts who specialize in green-renovation and green-retrofit industries is another good way to make sure you are getting regionally-specific information.

Solar Energy Resources Thu, 15 Apr 2010 20:41:09 -0400
Green-Building and Green Buildings ARRA and Sustainable Building
In signing into law the American Recovery and Reinvestment Act (ARRA), the federal government has ushered in a new era of “green” building. As part of this bill, the U.S. government has earmarked approximately $9 billion dollars to repair, renovate, and modernize school buildings to meet widely accepted green-building standards. In addition, the bill provides $16.8 billion for a wide array of programs within the Department of Energy; energy programs that extend to the residential consumer. Green-job training has been covered as well with as much as $10 billion dollars allocated to retrain and educate our workforce in core energy efficiency values, sustainable building practices, and alternative energy building trades.

The Invisible “Green” Revolution
Green-dollars spent on retrofitting 30-, 40-, 50-, even 100-year old public buildings aren’t seen from the street. Tax credits, abatements, and reductions for sustainable building practices and green-building standards, along with incentives and grants for certifications like LEED and Energy Star don’t warrant ribbon-cutting ceremonies. Still, the emphasis on upgrading of underlying mechanical systems is a technologically sound plan that utilizes current technologies in lighting, HVAC, insulation, and roofing systems to increase efficiencies in those systems and maps the savings on 5-, 10-, and 20-year timelines. For communities hard-hit by recent economic times, this is a boon for public building renovation projects that have been waiting for funding.

Green-building and Green Buildings
Jason Hartke, director of advocacy and public policy at the U.S. Green Building Council has said, “There is an amazing return on investment in greening existing public buildings, particularly schools. The programs that institute a focused plan for overcoming first costs and then use the utility and energy savings of green building to reflect savings over time have been the most successful.” This sums up nicely the challenges facing new “green” development: initial capital costs and a desire for short-term return on investment. Apparently, investing in green-building is very different than building green buildings.

What Are The Green Commercial Real Estate Projects?
John S. Konopka of Construction Advisory Group, Inc. said, “Commercial developers usually use a business model where they run the numbers backwards; analyzing the profit-return they require, and designating design and build solutions based on costs.” Additionally, as we all know, lenders aren’t lending. “Commercial loans that might have gone out the door with a loan-to-value of 70-30, many now require a 20% deposit,” Konopka said. Couple this with completion guarantees and occupancy guarantees and it’s easy to see why developers would be nervous. Adding in the additional upfront capital cost of solar power or wind energy design, installation and maintenance, the potential delays and cost-overruns caused by additional permitting and legal issues, the challenges of insuring both workmanship and materials on relatively new technologies, and the increases required in per square foot costs to the consumer, and it’s no wonder that “Green” is just not a priority for new commercial development projects.

Solar Energy Resources Thu, 15 Apr 2010 19:48:25 -0400
What is a Kilowatt Hour? What is a kilowatt hour?

Different types of energy are measured by different physical units: Barrels or gallons for petroleum, Cubic feet for natural gas, Tons for coal, and Kilowatt-hours for electricity

A kilowatt is a unit of power equal to 1000 watts. Wikpedia defines a watt as a “derived unit of power in the International System of units (SI), named after the 18th century Scottish engineer James Watt.  The unit symbol for a watt is “W” and the unit symbol for a kilowatt is “kW”.

A kilowatt hour is the amount of energy you get from one kilowatt for one hour. Electricity use over time is measured in kilowatt hours . Your electric company measures how much electricity you use in kilowatt hours, abbreviated “kWh”. An example of what one kilowatt-hour can do is: 1200 electric shaves, dry your hair 15 times, 4 TV evenings, use a small refrigerator for 24 hours or 4 evenings of light with 60W incandescent lamps. This according to

How many kilowatts does an average U.S.home use?

According to the U.S. Energy Information Administration, in 2008, the average annual electricity consumption for a U.S. residential utility customer was 11,040 kWh, an average of 920 kilowatt hours per month.  Tennessee had the highest annual consumption at 15,624 kWh and Maine the lowest at 6,252 kWh.

Solar Energy Resources Tue, 06 Apr 2010 19:17:37 -0400
3 Types of Residential Solar Electric Power Systems There are three main types of residential solar electric power systems: grid inter-tied; grid inter-tied with battery backup; and off-grid. These three broad types vary in how closely connected they are to the traditional power utility infrastructure, known as the grid. Each type has strengths that determine how suited they are to your needs.

Grid Inter-Tied Residential Solar Power Systems

A grid inter-tied solar power system is directly connected to the home and to the traditional electric utility grid. Grid inter-tied systems allow the homeowners to get power from either the home electric system or the utility grid. Switching between the residential system and the grid is seamless.

The prime advantage of this type of system is the ability to balance the system production and home power requirements. When a grid inter-tied system is producing more power than the home is consuming, the excess can be sold back to the utility in a practice known as net metering. When the system is not producing sufficient power, the home can draw power from the utility grid.

Grid inter-tied systems are the lowest cost type of residential solar electric system, due to having fewer required components.

Grid Inter-tied Residential Solar Power System with Battery Backup

A grid inter-tied solar power system is also connected to the traditional utility power grid and adds battery-backup to the system. The addition of a battery backup enables the system to balance production and demand and protects against power outages.

Solar electric system production depends on the available sunlight. When sunlight is abundant, production can exceed demand. When production exceeds demand, the excess power can charge the batteries, which store the electricity. When the system is producing less electricity than demanded by the home, the batteries can make up the shortfall.

Grid Inter-tied systems are also connected to the utility power grid. This enables the homeowners to draw from the grid during periods of excess demand and to sell power to the grid when there is excess production.

While grid inter-tied systems offer more flexibility, they are not without disadvantages. Charging and discharging batteries reduces the overall efficiency of the system and these systems are more complex to design and install and therefore more expensive.

Off Grid Solar Power Systems

An off-grid residential system is completely disconnected from the traditional electric power grid. Without a connection to the utility grid, batteries are essential to balance periods of excess production and excess demand.

To protect against shortfalls of power when the solar system is under-producing and the batteries are discharged, an electric generator is usually added to the system. The generator is used as a power source during periods of prolonged excess production or unusual demand.

All Systems

Within each type of system there are subtle variations in design that effect efficiency and convenience. To determine which system is best for you, review your requirements with a solar installation professional. A professional installer can guide you through the detailed choices of specific systems that best match your needs.

Solar Energy Resources Mon, 11 Jan 2010 19:44:59 -0500
How to Size Your Residential Solar Electric System Determining how large a residential solar electric power system is required for your home is dependent upon your usage and your goals for the system. Being completely free from utility power may be impractical due to your location, the space required for solar panels and cost. Typically, homeowners target offsetting 40-50% of their average monthly electrical usage as a reasonable goal for their solar electric power system.

Home power usage varies based on the number and efficiency of your appliances, whether you heat or air condition with electricity, hot water source and your cooking and clothes drying power sources.

Your best source for information on your consumption is your electric bill. Your electric bill will have your usage in kilowatt hours. To determine your average monthly usage, gather the kilowatt usage from your last twelve bills and divide by twelve to get your average monthly usage. You may also be able to call your utility company for the information. Using a year’s worth of information enables you to factor in seasonal fluctuations. You will also want to know your peak usage requirements.

Cold northern locations usually find peak electrical usage during the winter months, when days are shorter and lights are used longer. Warm locations find peak usage is during the summer when air conditioning is used.

Once you know how much electricity you consume, talking with a solar installer can help narrow the options. A professional will know the specifics of available residential solar systems and can match your requirements with systems in the marketplace.

The output of your solar electric system depends on how far north you are and the weather patterns in your area. Maps such as these from the US Renewable Energy Laboratory can help you determine how much solar radiation you can expect for your location.

Weather and the number of daylight hours play the greatest role in how much power your solar electric system will generate. Solar panels produce electricity when struck by direct sunlight, regardless of air temperature. A clear, bright cold day is almost as good, as a summer day when the sun is overhead. In summer, the longer daylight hours enable your system to generate power longer. On cloudy days, your system will produce power – but not as much.

The number of solar panels required to reach your target system output will vary by manufacture and whether the panels are fixed or moving solar panels. Panels that move with the sun can be continuously angled to optimize direct sun exposure.

Typical solar panels are two to four feet wide and four to six feet long. Each panel will generate between 10 and 300 watts depending on the type and efficiency of the panel. One hundred watts is a reasonable number to use for rough estimates on the number of panels required for your application.

Solar Energy Resources Wed, 06 Jan 2010 20:50:43 -0500
Selling Residential Solar Power to Your Utility Company One benefit of a residential solar power system is the ability to offset your electric costs by selling excess power back to your local utility company.

Home solar electric systems produce power continuously during the hours of direct sunlight. Frequently, the power produced during these hours is more than the power consumed by the home during the same time period.

Electricity is volatile: you must use it immediately or store it in a battery or it is lost forever. Systems equipped with batteries have maintenance costs and disposal issues. In addition, storing electricity in batteries results in some loss, since batteries are not 100% efficient.

Selling the excess power to your utility can be a favorable alternative to storage, depending on how much your utility pays for the electricity it buys. Your state laws will determine the rate your utility must pay and not all states allow it. Usually, your utility will not be required to pay as much as a consumer pays for electricity.

When your residential solar power system is configured to sell power to the electric company, a two-way meter is installed to measure the amount of current flowing from your residential solar system back to the utility’s electric grid. The term “electric grid” refers to the wires and infrastructure used to generate and deliver power from a utility company.

The practice of selling power to your utility company is known as net metering. The term “net metering” is used because the amount sold is the difference, or net, between the metered usage of the home and the metered current flowing back into the grid.

There are strict codes that apply when you connect your residential power systems to the utility’s electric grid. A professional solar power installer from your area can design and install your system so it is in compliance with local codes, ensuring that you are eligible for net metering.

Solar Energy Resources Wed, 06 Jan 2010 19:48:14 -0500
Home Solar Panels: An Overview Solar panels are the most recognizable component of a residential solar electric system. The solar panels are installed on the roof of a home to collect sunlight and convert the sunlight into electricity. Homeowners install residential solar electric systems to save on electric costs and lessen their environmental impact.

Each solar panel is a collection of solar cells. Solar cells are the component of a solar panel that converts sunlight into electricity.

The solar cells produce electricity by the photovoltaic effect. The photovoltaic effect is produced when sunlight is absorbed by a semiconducting material, such as silicon, and the sunlight separates electrons from their atoms. These electrons travel into a circuit in the solar cell to form a direct (DC) electrical current.

Home based solar panels, also called photovoltaic panels, produce from 10 to 300 watts per panel. To produce a useful quantity of electricity, solar panels are combined to create solar arrays.

Because solar panels only produce electricity during the daytime and homes need electricity at night, there is a mismatch between electricity production and the demands of the home. To overcome this mismatch, systems frequently have batteries to store the excess electricity. The batteries power the home when the panels are not producing.

Batteries can be expensive and have maintenance and disposal issues. As an alternative to storing the excess produced during the day, some systems are configured to transfer the excess production to the local power utility’s system. In exchange, the power utility gives the homeowner credits that are used to purchase electricity when the solar system is not producing. This exchange of credits for electricity is called net metering.

Solar panels and batteries produce direct (DC) electric current. Household appliances use a type of electric current called alternating (AC) current. A device called an inverter converts the DC current produced by the solar panels and batteries to the AC current required by appliances.

Wiring, grounding and over-current protection complete the major components of a household system.

Installation of a residential solar electric system requires expertise in wiring, electricity, carpentry and solar electric products. Homeowners interested in installing a residential solar electric system can benefit by talking to an expert. To find an expert in your area, see our Directory of Installers.

 by Bob LoCicero.


Solar Energy Resources Wed, 06 Jan 2010 19:29:48 -0500
Components of A Residential Solar Electric System A complete home solar electric system requires components to produce electricity, convert power into alternating current that can be used by home appliances, store excess electricity and maintain safety.

Solar Panels

Solar panels are the most noticeable component of a residential solar electric system. The solar panels are installed outside the home, typically on the roof and convert sunlight into electricity.

Solar Energy Resources Wed, 06 Jan 2010 19:27:45 -0500
The Ins and Outs of Net Metering When it comes to solar energy in the form of electricity, you are going to need a special metering system that will determine or measure the amount of energy that a particular appliance is receiving.

If you are installing solar panel equipment, such as solar cells, batteries, reflectors and such, you should also include on your supply list a thermostat, power breaker and a meter for gauging the amount of kilowatts being used. As you can see, solar panels alone do not make for a solar system by itself.

If you are still using your conventional electric company to deliver all your electrical needs, you know that they keep up with how much electricity you are using by reading that meter sitting outside, on the side of your house. You might even have seen the meter person coming around to check your meter and then they type in the figures to their hand-held computerized instrument that feeds the information to your electrical supplier; and then in a week or two, presto - you have a bill that is out of control.

Well, with solar energy metering, you will not get such high readings because during the day, while your panels or wind turbine is hard at work, you are going to receive more energy than what you can possibly use in a 24 hour period, especially if you are at work for, say, 10 of those hours. When this happens, the excess power that is unused is sent to your utility company’s power grid, by way of the electric meter, which is then spinning backwards instead of going forward, and this in turn will release a reading of energy saved or stored.

If you are off grid, your utility company will or should supply you with a new meter, one that is called a 2-way digital meter. This form of metering is referred to as net metering.  When you are in this mode of metering, you can look forward to your power company giving you credit (or paying out cash to you) for the energy that your solar energy system creates in excess - after you produced more than you could use. As you know, your current conventional method does not pay you back anything, except for crediting your account for overpayment. For example, if you received a bill for $200.00, and you somehow wrote a check out for $300.00, that extra $100.00 will be given to your account for the following month’s bill, therefore, causing you to receive credit for $100.00, and if your next bill is $75.00, then you do not have to pay the current bill because you have credit for it already. You see, with the conventional way, that extra money you sent them is put it in the bank until it is all used up.

In simple terms, net metering is the difference between the electricity you buy from Miss Utility, and the electricity that you actually produce from your solar energy system.

When you are thinking about doing net metering, it would be wise to contact your electric company to see if they honor net metering. If so, you will probably have to sign an agreement and go through an approval process before receiving a new meter.

With net metering, when your solar energy is low, you can still receive support from your utility grid. Receiving power from the utility company, which is actually the excess that you have already produced, means you won’t have to use a generator or battery system because Miss Utility will have your back.

There are 25 states that offer net metering, some offer credit and some offer a payout in cash. New York, New Jersey and Pennsylvania are among the 25; each with their own rules and regulations. So if you are lucky enough to live in any of these states, you should be good to go with your solar energy system and net metering.

Speaking of rules and regulations that come with your utility company; as an added resource tip to this article on net metering, I can’t help but remind you that though you have decided to use solar energy for your home, there may still be some rules and regulations that you must go through and follow with your electrical company whether you are on grid or not. You may even have to qualify for the net metering or be considered eligible. Regardless of what kind of system you are using, panels or wind turbines, you may have to adapt to new rules and regulations.

For a wind turbine system, it may have to meet standard electrical codes of your city or state, meeting all requirements for safety, wiring and installment. In other words, you may have to get a permit to even think about net metering for your system.

Again, check with your utility company to be on the safe side of installing and creating, and in being eligible for net metering whether you are using wind or any other solar alternative.

It’s better to be on the safe side than to have someone come along at any given time and tell you that you have to take it down because it is not up to code or that you didn’t get a permit before you began work on installing the system.

One thing’s for sure though, if your city regulates or sets standards for solar energy systems in your area and you do not follow them, you can kiss your tax break and cash pay outs good bye. Even if they say you need a qualified professional to do some electrical work, you better adhere and not try to do it yourself. After all, I believe they have ways of finding out when someone is trying to slip through the crack.
Enjoy Your Savings in Net Metering!

Solar Energy Resources Fri, 24 Apr 2009 14:34:57 -0400
The Geothermal Advantage With the seasons are changing, and cold air is beginning to enter your comfort zone of warmth; you know it is time to prepare your home for the winter blues of drafts coming through windows and under doors.

You realize that it is time to add new weather stripping and change the filter on your 50 year old furnace to try and save some money on your heating bill. Yet no matter what you do as you go about doubling up your sweaters and long sleeve shirts, and no matter how many heavy blankets you pile on the bed at night to feel nice and cozy without having to spend out extra money to be warm; it is going to happen anyway. You are going to be bombarded with high heating bills for about 4-5 months, or for how long cold weather stays around where you live.

Your utility company has already warned you, letting you know what to expect and when it is going to happen. I guess it is their way of easing into winter and adding high fuel costs to your kilowatt usage before you even start to regulate your thermostat.  They might have made this big announcement to prepare you since way back in August.

Even if you sleep in front of your stove without turning your furnace on,  or if you sleep in front of your living room log fireplace if you have one - this will not keep you from seeing a higher gas bill this winter as it is already regulated, already estimated, already predicted and already in the making that consumers, rich or poor; homeowners and business owners alike are going to be reaching deeper into their pockets, or deeper into their banking accounts, to meet the elevated cost of heating.

This is happening because consumers are caught up in this maze of economic dependency on their local utility company’s power grid that brings gas and electricity to their homes and businesses, instead of relying on solar energy that is cheap and affordable. Heck, most often it is free; so why are you paying extra to heat or cool your homes when you don’t have to? This is something you should be pondering; especially since there is a way to draw energy for heat from a solar device.

Another source of solar energy besides solar panels, wind turbines and solar hot water systems is solar geothermal systems which will bring heat into your home.

As you can see, we have come a long way from the dark ages with solar energy, and just like you have a choice in what heating company you are going to use; for instance having heating oil delivered to your home, or using coal and wood, or staying tapped in to your city’s power source; you have a choice in the way that you can use this free energy driven from the sun, or driven from the earth. You have a choice in how you are going to bring electricity and gas into your home, after all, these are elements that are a necessity and we can’t get around that fact because we do not want to be left in the dark or in the cold.

What is geothermal anyway? Geothermal is heat that is collected from the earth, since there is thermal energy housed in rocks and water deep in the earth’s crust. You can use this resource from the earth in heating systems that do not require heat pumps or power plants. This kind of heating is called a direct heating system, because the energy comes straight from the earth’s water.

The other option is called a ground source heat pump system, and for this system a pump uses the water from the earth as a source of heat for the winter months. In addition, it can be used as a heat sink during the summer. And yes, geothermal is another renewable energy resource.

You can use geothermal heating systems in places such as newly built schools or swimming pools, and even for residences - it could be provided in space heating. All I can say is, where there is a will, there is a way.

This kind of solar heating system, I guess you can say, is a dual supplier of energy because it can also produce electricity that can be added to an electricity grid.

For residential homes, old and new, consumers are finding out about this natural heating and cooling system. It is becoming more and more popular because the savings that one encounters on their utility bills proves that this source of energy is cost effective. A 2,000 square foot home can be cooled off and heated for about $50.00 a month or less. How cool is that? It is better than paying 2 or 3 hundred dollars to be nice and cozy and you have electricity too!

With a geothermal system, this is what you can expect and depend upon.
1.    The system, when installed, can be indoors or underground.
2.    There are few parts that wear out, so there will be very low maintenance.
3.    There are no irritating noises from the condenser fans.
4.    This system is not affected by outside temperatures. Regardless of the seasons, it will work adequately, because it is not affected by temperatures - whether freezing or sweltering.

With this kind of system, you are going to be charged with two kinds of prices. Do not be alarmed with this bit of information, because what you are actually paying for is purchasing the equipment for one price and running the system for another price.

Again, just like all other solar energy products and systems, it pays for itself in due time and the savings will show up on your utility bills. However, there are other benefits too, but that will come later in another article.

Solar Energy Resources Fri, 24 Apr 2009 13:49:27 -0400
Heating It Up With Solar Regardless of what you may think or what you may have heard; solar energy isn’t just for generating or producing electricity to light up your home. If you believe that solar solely runs electricity then your beliefs are faulty.

Though you cannot produce hot water with regular solar panels that bring electricity to your “solar-fied” residence, you can produce energy to heat your home through other solar heating methods or means, and all work in adjacent to the solar electrical resources.

Solar Energy Resources Fri, 24 Apr 2009 13:33:10 -0400
The Grid Link In today’s society of soaring energy prices that are putting a damper on any consumer’s wallet, it is a good thing to know that as consumers we have choices when it comes to dealing with this enormous energy problem. Just because oil and gas prices are reaching astronomical heights, we do not have to stand for it if we can help it.

Just like there are practical solutions to beat the high prices at the gas station, there are also practical solutions for high electrical prices when it comes to running our homes.

What are consumers doing when they cannot afford to drive their automobiles to work? The practical solutions would be: carpool, public transportation, walking, biking, going hybrid or simply working from home if that can be a money and gas saving remedy.

Ahhh, problem solved for the gas tank issue!

But still, how do consumers solve the issue of high energy or high electrical bills when it comes to running their homes? Today, it is as if the multi-billion dollar energy suppliers are controlling our home lives - regulating how much we are going to spend to fuel our homes in the winter and how we are going to cool it off in the summer. Even when we can’t afford the cost, we manage to pay for it through “budget plans” allotted to consumers when utility prices start squeezing us to death like a Python snake.

Budget plans, or moving in with neighbors, family or friends are not the only solutions to dealing with sky rocketing utility or electrical bills - where you split everything right down the middle to have a roof over your head. Is that the American dream or the way of the future?

The solution for this scenario is going solar. That’s right, solar power to the rescue! Just like Superman coming to save the day; the sun’s powerful energy is the “other” resource for consumers. Just like there was a bailout for Wall Street, the sun’s everlasting solar energy is the bailout plan for consumers and homeowners when it comes to economizing. This resource option is a dream come true; after all, the sun does more than just shine. As a child, we learned the benefits of the sun and the power it has to energize the earth - this wasn’t a fairytale or a breath of fiction just to make one feel good. There is truth in facts and for today, the facts bring solutions to the energy and electric crisis when it comes to powering our homes with efficient and ample energy - energy that has always been around ever since God said, “Let There Be Light.”

They used to say that everything has a price tag attached to it; however, let me remind you once more, energy from the sun is a totally free resource. The only thing that consumers would have to pay for is the actual device in which energy is transported and converted in so that we can use that energy and benefit from it.

The device comes in form of solar power, wind power, and geometrical power; with devices such as solar panels, wind mills or turbines and satellites - all of which are renewable energy resources that are generated from the sun’s planet.

With this option, the consumer has the choice of an on-grid or off-grid supply. This simply means deciding whether your home is going to remain connected to your power company’s utility grid or power lines from electrical poles on the street in which you live.

This is the “grid link” option for consumers, an option that works either way if you are considering going solar. You will not be left in the dark because you chose one over the other, and you will still see quite a difference in your electrical bill and savings if you choose to be grid tied, or connected to your power company’s source of energy.

However, once gone off-grid, you will find that your home’s energy is completely free and without monthly anticipated bills. Right now you should be asking yourself, “Which is it going to be, on-grid or off-grid?” Let’s look at the differences:

Off-grid: Off-grid means that your home is independent from power lines and can be powered through solar panels, wind generators or gas generators and hydro-power - you can even get fancy and combine all of them together, having multiple systems running your home.

Off-grid allows consumers to only use what they produce by the above mentioned power sources. Any power off-grid source runs normal AC appliances like refrigerators.

When running your home on wind power, it is a fact that you must live in a windy area for this system to be practical and efficient, otherwise it will not work.
Though gas generators are resourceful, they are somewhat noisy when they are in use. They will also give you a headache because starting them has been proven to be a bit on the difficult side. In addition, gas generators need more maintenance and you will need to transport fuel to them - this is the only solar resource that has its drawbacks or pit falls.

You can run your off-grid power system in RVs and boats, for those who love to travel. You have at your disposal: off-grid solar (which is the sun’s energy), off-grid DC (which is run by a generator) and off-grid wind (which is run by a wind turbine). With all of these available resources, you can have a battery back up system for extra support.

On-grid: Most residential consumers choose to be plugged into their local electrical company’s supply source, which is what on-grid is all about.
Your home’s roof top must be in direct sunlight to benefit from the sun’s energy output. If your home is hidden in a dense population of shady trees, a solar energy system may not be the ideal solution.

For an on-grid system, energy is stored during the day - when it produces more than what is used - the excess is then returned to the power company’s grid, and in return, your power company will give you credit to your account.

Another on-grid fact is that during the night, your household electrical needs are being met by your power company since the sun doesn’t shine at night or during cloudy days. If your system doesn’t produce enough energy, your power company will step in and make up the difference.
Residential solar power systems do not give hot water, nor do they add heat to your home, because it is an electrical system which gives light and makes electrical appliances and apparatuses work - it has nothing to do with gas operations.


Solar Energy Resources Fri, 24 Apr 2009 13:31:25 -0400
Solar Glossary Are you interested in solar electricity, but not sure what "photovoltaic conversion efficiency" means? You're not alone. In fact, because technical terms like these come up frequently, especially in discussions of photovoltaics (PV), we prepared this glossary of terms. In it you will find definitions of many important terms having to do with electricity, power generation, concentrating solar power (CSP), solar heating, solar lighting, and solar electricity, also known as PV.

Solar Energy Resources Fri, 24 Apr 2009 11:37:30 -0400
Solar Energy Can Save You Money When the sun is shining, your solar system generates electricity, which means you will purchase less electricity from the local utility. Over the course of one year, your utility will track the amount of electricity your system has fed into the grid and use this credit to offset the costs of power purchased from the utility during peak usage or at night when your system does not generate electricity.]]> Solar Energy Resources Wed, 08 Apr 2009 19:33:35 -0400 Hiring a PV Pro Finding a solar-electric system installer is like choosing a long distance phone company it can be as simple or as complicated as you make it. You can let your fingers do the walking and choose the first one you find in your local yellow pages, or you can do additional research and find an installer that best meets your needs. Mail-order companies, large discount warehouses, small mom-and pop businesses, and large corporations all sell and install renewable energy(RE) systems. As the number of dealers, distributors, and installers grows, being an informed consumer is increasingly important. And just like buying a car or a computer, you'll want to be sure that the person designing and installing your new system has the expertise to provide you with an efficient, safe, and reliable system.

Think Local

To locate an installer near you, you can always inquire with your local solar organization. The American Solar Energy Society (ASES) has chapters in 34 states, and your local chapter can provide you with a list of installers and dealers (see Access). ASES also cosponsors the Find Solar Web site at, where you can find detailed listings of PV pros across the United States and Canada. If you live in the Heartland, the Midwest Renewable Energy Association offers a great resource for finding an installer. You can also check out Home Powers Web site for a searchable database of RE dealers and installers, or look in the Installers Directory at the back of each issue. Most of us want the best product for the least cost. Shopping by price is important, especially if you are on a tight budget, but there are also other factors to consider. Following is a list of some of the issues to think about when selecting an installer.


Professional Credentials.
Organizations are now certifying installers by a set of standards, and asking for an installer's credentials can give you an idea of these qualifications. The North American Board of Certified Energy Practitioners (NABCEP) offers PV certification on two levels an Entry Level Certificate of Knowledge, and a PV Installer Certification. According to NABCEP, Certification is not intended to prevent qualified individuals from installing PV systems it is meant to provide a set of national standards by which PV installers with skills and experience can distinguish themselves. That said, many seasoned pros who have been in the business for years don't see the need for additional certification. They may not choose to dedicate the extra time or expense to become NABCEP certified.


Electrical License
If you contract with an installer who doesn't have an electrical license, you or your installer will also need to hire a licensed electrician to obtain the permit, supervise the job, and do the final AC hookups. Regulations for residential electrical work vary from state to state, so be sure to check with your local building department prior to system installation. Your installer should have a good working relationship with the local electrical inspector. Also, if you expect to take advantage of financial incentives, be aware that most states won't provide rebates if the installer isn't licensed.


Bonded & Insured
It's always a good idea to check if your installer has liability insurance. This insurance coverage protects you against any installation mishaps if the installer's work damages your house during or after the installation. Some installers advertise that they are bonded as well. This guarantees that the contractor will meet his or her obligations in a satisfactory manner. Failure to do so results in the bonding company paying you compensation. However, being bonded is expensive, so if you want an installer who is both bonded and insured, you'll probably have to forego a mom and- pop operation for a large installation company.


How recently and where has your installer been educated and trained? Find out if the installer has kept up-to date with training courses on the specific products he or she sells. Many companies that manufacture and distribute RE products offer training, enabling installers to stay current on new product developments.
Solar Energy Resources Wed, 08 Apr 2009 19:32:27 -0400