How Much Money Will Solar Panels Save Each Month?

Numbers in regard to solar panels, such as monthly savings, payback period, and others, depend on several factors. These include system size, placement in regard to the sun, location of the home, your energy lifestyle, and local electricity costs, among others. The only true way to determine your specific monthly savings is to have a site analysis performed by a local solar installer. There are also several online calculators that can give you a pretty good idea of monthly and long-term savings.

However, using some national averages, calculating the general difference in monthly electric bills incurred by an installed and functional solar PV system is actually quite easy. Let’s say you live on the temperate Pacific Coast, which includes Washington, Oregon, and California. According to the Department of Energy, the average household in this area pays about $63 per month for electricity. These numbers are for 2002, however, so, assuming a 7% increase in costs per year, that would put the average electricity bill in this region at roughly $108 per month in 2008.

So, assuming a 3 kW system is installed and there are roughly 6 hours of sunlight per day, we can then calculate the system output at 18 kilowatt-hours per day. That translates into roughly 540 kWh per month. After adjusting that number for cloudy or rainy days (decreasing it by 20 percent), we get a more realistic output of 432 kWh per month for the PV system. (more…)

How Much Money Will Solar Panels Save Each Month?