Solar Terms | Solar Glossary
If you’re thinking about installing a solar power system to cut the cost of powering your home, you might be confused by the unfamiliar (and often esoteric) jargon of the industry. Fear not. This glossary is a great starting point to getting familiarized with the language. You’ll be able to ask pertinent questions and have informed responses if you decide to talk to a professional solar installer. Here is a simple glossary of the most common terms you’ll come across on your path to cleaner energy.
Photovoltaic
Photovoltaics are the technology that converts solar radiation from the sun into DC electricity. “Photo” refers to the radiant energy source (light), and “voltaic” refers to the tangible electric output.
Rebates and incentives
Rebates and incentives are offered by government agencies and private companies in order to make solar power more affordable while simultaneously stimulating the industry. Solar rebates and incentives are two different ways of offsetting the cost of having clean energy. And, in most states, you can take advantage of many different ways solar energy in your home is made more affordable. While many programs work together in order to save you the most, their differences are highlighted here:
- Rebates tend to be a lump sum of money reimbursed to you based on how much energy your PV system is expected to produce over a certain period of time and/or based on how much money you’ve invested. For example, your utility company might offer you a one-time payment of $2 for each watt of potential energy you’ve installed.
- Incentives tend to be performance-based, reimbursing you for the energy your solar system has produced at a pre-determined rate. For example, if you are producing more energy than your household is using, your utility company might buy the excess energy produced by your system at the rate of, say, $0.05 per watt.
Active vs. passive solar
As you click through online resources about what rebates and incentives are offered in your state, you will likely come across the terms “active and passive solar.” The difference is that in active solar, the sun’s rays are actually being converted into electricity. With passive solar, on the other hand, the sun’s rays are harnessed for their heat, as in a greenhouse, for example.
Fixed, adjustable, and tracking solar panels
A solar panel is supported by either a fixed, adjustable, or tracking stand. The fixed support is the most economical, but the adjustable and tracking ones increase the efficiency of your panel.
- Fixed solar panels, which are the most affordable option, are on an unmoving base. When installed, they will be oriented in a way that will capture the sun’s rays to the best of their stationary ability.
- Adjustable solar panels can be manually adjusted a few times over the year when the sun’s path gets lower or higher in the sky as the seasons change.
- Tracking solar panels are the most expensive of the three options, but also the most efficient at capturing the sun’s energy. These panels mechanically follow the path of the sun. There are single axis mounts, which track the east-west movement of the sun, and double-axis mounts, which track the east-west movement, as well as the seasonal changes, as the sun’s path gets closer and farther from the horizon.
On and off the grid
When your electricity is on the grid, you can pull electricity from the utility power grid that your home is connected to when your system isn’t producing energy, such as at night. When you are off the grid, it’s necessary to have power generators and/or batteries to store the power produced by your system during the day to draw energy from at night or in overcast conditions.
Renewable Portfolio Standard
Most states (currently 30) have enacted a Renewable Portfolio Standard (RPS) which requires that an increasing amount of energy is drawn from renewable energy sources, such as solar, wind, biomass, and geothermal. In order to fulfill this obligation, electricity-providing companies buy renewable energy credits (RECs) from owners of renewable energy systems.
Net metering
Both the energy produced and the energy consumed in a home or building with a renewable energy system can be measured using net metering. If more energy is produced than is consumed on premise, the owner of the system will receive credits and usually reimbursement. The rates and methods of reimbursement vary depending on the state and utility company.
A watt and its multiples
The smallest measurement of electricity we generally use when talking about solar energy is a watt. For example, your utility company might reimburse you for $.05 for each watt of excess energy produced by your renewable energy system.
- A kilowatt (kW) is equal to 1,000 watts.
- A megawatt (MW) is equal to 1,000 kilowatts or 1,000,000 watts.
- A kilowatt hour (kWh) is how much energy is produced by a kW for the duration of an hour.
