There still seems to be plenty of confusion and doubt concerning the ability of the sun to provide sufficient energy in certain parts of the continental United States.
The technical term for the amount of available solar energy reaching the surface of the planet is called solar irradiation. While the amount of solar irradiation is less in more northern parts of the country, there’s still plenty available to make solar viable.
Unfortunately, some of this confusion comes directly from the National Renewable Energy Laboratory. In the following two images, the NREL’s makes it appear like the potential solar irradiance drops off significantly for parts of the country that are not in the South West. The reality of the matter, which can be seen from an image on the right provided by William Driscoll from PV Magazine USA, shows that a good percentage of the solar potential is still available across the U.S. In fact, other parts of the country have at least 70 percent of what the South West has.
To put this massive solar potential another way, only a 160 square kilometer piece of land would be required to provide enough power for the whole country. That’s a very tiny percentage of the total land available. Of course, one of the great things about solar is that it is easily distributable. Obviously, solar power plants can be built virtually anywhere. The point here is to highlight the fact that space is not an issue as we transition to a solar plus battery storage energy infrastructure.
From a practical perspective, homeowners in the more northern states would require an extra solar panel or two to match the amount of energy captured in the southern states. Is this significantly more expensive? Not at all, this would add approximately $300 to $600 to the total cost.
The, on average, cooler northern states actually have an advantage over some of the hotter parts of the country. The reason is that many electronics, including solar panels, are slightly less efficient in hotter temperatures. Solar panel systems require light, not heat.
In summary, the United States has an incredible potential for the expansion of its use of solar energy. We are still early days for our transition to renewable energy. Those homeowners, businesses, and utilities that decide to invest in solar power now will find that they can build solar systems to provide all of the power they need. Starting now will have them saving money sooner than later too!