Frequently Asked Questions
There are several factors that determine the amount of electricity generated by a solar system. The primary factors are system size, shading and orientation of the system. In Minnesota, a 1 kW PV system, using about 120 square feet of solar panels, will typically generate about 1,300 kWh per year. The average household in Minnesota uses about 9,000 kWh per year.
The size you choose depends on the amount of money you want to invest and the amount of electricity you want to produce. During peak demand periods in the summer, a large home could use up to 5kW of capacity at any given time. That same home could use approximately 12,000 kWh of electricity over a year. Look at your past bills to determine the amount you want to cover with solar electricity. The only other condition in determining proper system size is the amount of suitable space available on your roof or property. A suitable area must be unobstructed and not shaded, either flat or sloped, and at an orientation other than north (a southern orientation is ideal). You need roughly 120 square feet of roof space for each kilowatt of PV capacity you wish to install.
A PV system could generally produce 10 to 40 percent of annual residential heating needs; the system size impacts production. The system size you choose depends on how large an investment you want to make and how much unshaded space is available.
To have a PV system installed, your roof/property must have a non-shaded southern exposure and an unobstructed space during the day, and the system panels must face south. Your roof can be flat or sloped. Rack–mounted systems on the ground are also an option.
The links below show examples of what your bill will look like:
The PV system automatically shuts down as soon as it detects an outage on the electric grid. This protects the integrity of the electric grid, and also ensures the safety of those working to correct the outage. If you have a battery backup, you can run off your batteries without any back-feed onto the electric grid.
Typically, PV systems operate in air temperatures ranging from -40° to 120° F. PV systems are electronic devices that generate electricity directly from sunlight. Output will drop as the system gets hotter, due to increasing temperatures on the roof. However, in the summer months the increased daylight hours increase production.
Since PV systems require sunlight to produce electricity, your system will not produce at night.
The bulk of your electricity production will take place during sunny conditions, since PV systems require sunlight to produce electricity. Output is directly proportional to the amount of sunlight available at any given moment. A system can generate 50–70 percent of its typical output under bright overcast conditions, but production will continue to diminish as less light reaches your system.