Let’s say it’s a gorgeous day, you’re looking at your roof and thinking it’s finally time to go solar. Or you’re sitting at work, wondering how much power your solar array is putting out.

Either way, there are a bunch of apps for mobile devices like iPhones and iPads that can help you out. There are also some solar apps that work with Android- or Windows-powered smartphones and tablets that do the same.

If you’re interested in checking out solar for your home or business, the Mr. Sun app is one free option. This app harnesses the power of the iPad’s digital compass and GPS capabilities.

The software calculates your longitude and latitude, the elevation and angle of the sun throughout the day, and you select any date or time throughout the year to see how much sun your location can expect. You can take this data and use it in solar estimator tools, to show you how much solar your site can handle or how much it will produce.

Mr. Sun’s a great starting point, but if you want more comprehensive information, check out the free Solarchecker app by SMA Solar Technology AG. This iPhone app also harnesses the power of the device’s digital compass and its GPS information to figure out your location and whether or not it’s a great spot for photovoltaics.

The Solarchecker also calculates the size of photovoltaic array based on the square footage you want the system to be. After that, it calculates what the size and capacity of a theoretical system would be. Based on your input, it calculates how much local feed-in tariffs would pay annually and what the rate of return is. It also calculates loan interest rates, rate of return, revenue generated by the system and more.

Finally, under its contact tool, it gives you contact information of local solar installers, allowing you to call, email, or visit their Web site directly from the app.

Another comprehensive app is the PV Master app. This iPad and iPhone app runs $11.99 and is a comprehensive tool intended to help solar professionals calculate basically all aspects of a photovoltaic array. This includes weather information like clear sky days, hourly angle of the sun throughout the year and more.

It doesn’t stop there, though. The app generates information on the size of system you’ll need and how many panels would be in it. It also calculates what the size a battery backup would have to be for a proposed system. The app also includes a guide and a glossary where users can get more information.

Basically, it’s like having a solar engineer at your fingertips.

That’s all fine and dandy, but what if you want to check production on your existing system, and you’re not near a computer? There are apps for that, too!

Some companies, like SunPower, already include interfaces through which you can check the production of your system online. They’ve now taken that mobile and have developed an app for the iPhone, which shows the current production of a SunPower system, the lifetime production and other metrics, including monthly and annual production. And they’re not the only company with such apps. With the SunPower system and systems like it, you can download the monitoring app from the app store and log in to your system’s monitoring data.

If you’ve got a PV system connected to the Internet, check with your installer or the inverter manufacturer to see if they have an app available for your system. They might: they might not. If not, some other companies have developed mobile apps that can tie into your system and give you monitoring data. But it’s more likely that you may have to add some more hardware to your system.

For instance, natcon7 offers a free monitoring app for their monitoring system, but you still have to buy the hardware. Other companies, like SolarPower, also offer such services.

In the end, these convenient apps only have you a tap, click, or slide away from what your solar potential is or what your system is currently producing. Check them out and enjoy.