You and I probably agree that solar is awesome. But does it make financial sense? To get an answer, we need to know three things: how much energy will be produced, how much the system will cost, and how are we going to come up with money to pay for it.
How much energy will my system generate?
To get an estimate on that, we will head to PVWatts, enter our ZIP code (I’m using 20147 in Northern Virginia), choose a nearby weather station, then enter 1 for the system size (that’s kilowatts) and 33.7 for tilt — an equivalent to a fairly typical 8/12 roof pitch. The reason I’m looking at a 1 kW system is that we can use its numbers to get an estimate for any other size just by multiplying. If a 1 kW system generates $100 worth of electricity, then a 2 kW system will produce $200, it’s that simple.