First, let’s Lets take a look at the the global PV market. The following chart illustrates that as of 2010, Germany has over 7 times the amount of installed solar power then the United States. Please note that GW stands for Gigawatt.
Looking at the above map really gives us a nice visual picture of how little solar radiation there is in Germany.
The map also shows us that the solar hot spot of the United States is the Southwest. So a solar PV system is probably a much better investment in somewhere like Arizona rather then New Hampshire. Right? Not so fast my friends.
I did a comparison of two PV systems both rated at 4000 watts. One system in Concord, NH and the other in Phoenix, Arizona. The Phoenix system produces an annual savings in electricity of $550. The system in Concord produces $618 in annual savings!
How can this be? The reason is that we simply pay more for electricity in New Hampshire. Approximately $.12/kWh compared to $.08/kWh in Arizona. Cost of electricity is an essential part to any return on investment calculation.
You can try your own solar analysis by using the very user friendly program called PVwatts:
Let me know what you find!