The Best States for Solar Power

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A PV array in Arizona — one of the best places in the United States for generating solar power.

Wherever there’s sunlight, you can take advantage of solar energy. However, different places have different solar resources, so the same set of photovoltaic (PV) panels will produce much more electricity in some locations than in others.

Many factors make a difference in how much electricity a PV system can produce at any one time — including constantly changing factors such as time of day, season and weather, but also geographic traits such as climate and latitude. In general, areas closer to the equator have far greater potential for producing solar electricity than those closer to the poles, and areas with consistent sun have greater solar potential then areas that are frequently overcast.

As a whole, the United States has terrific solar resources. For perspective, check out the map of global solar radiation from the United Nations Environment Programme. Now consider that Germany and Spain lead the world in installed PV power. The United States is currently third in installed PV power worldwide, but has far greater natural solar resources than either Spain or Germany.

But while the United States has strong solar potential across the country, some states are definitely sunnier than others. Here’s how you can find out which states have the best natural solar resources, and which have policies that support the development of solar power.

Naturally Sunny States

For the absolute best solar resources in the United States, think southwest.

Take a look at this solar resources map from the National Renewable Energy Laboratory (NREL). Based on this map, New Mexico and Arizona are red hot with solar potential, and California, Nevada, Texas, Utah and Colorado also have large areas highly favorable for PV development. PV systems will generate more electricity in these spots — and therefore earn more money — than PV panels in areas with fewer natural solar resources.

Both this U.S. map and the global map mentioned above use a common measurement of solar irradiation, which is kwh/m2/day, also known as peak sun hours. Here’s more information about peak sun hours and how you can calculate them for your location using the PV Watts1 website.

For yet another look at solar resources state-by-state, check out the U.S. Energy Information Administration (EIA) state energy profiles. This is a set of maps and energy profiles of all 50 states. Any areas with above six peak sun hours per day are shaded on the maps to indicate that they are good sites to consider for future solar projects.

States with the Best Solar Incentives

Incentives for installing solar power vary widely across the United States. While some incentives are available from the federal government (including a federal tax credit of 30 percent for residential solar-electric systems) many other incentives are offered on the state level.

The best place to find all the details about renewable energy incentives is the Database of State Incentives for Renewables and Efficiency (DSIRE). Here’s a state-by-state list of all PV incentives, including those for large commercial projects as well as those available to homeowners.

But looking specifically at incentives for homeowners, which states offer the most support for solar energy?

Here are their top 10 states with the highest Solar Power Ratings:

  1. Louisiana
  2. Oregon
  3. Connecticut
  4. Massachusetts
  5. New York
  6. Hawaii
  7. North Carolina
  8. Wisconsin
  9. Illinois
  10. Minnesota

Solar Go-getters: States That Are Making It Happen

So here’s a quick pop quiz: When it comes to total installed solar power, one state is definitely leading the pack. Any idea which one?

To find out, we can take a look at the Interstate Renewable Energy Council (IREC) — it shows which states had installed the most megawatts of grid-connected PV power through 2008.  These numbers include both home-scale systems and larger, non-residential systems. There’s much more detail in the report about exactly how those numbers break down, but here are the top 10 states with the most installed PV systems:

  1. California
  2. New Jersey
  3. Colorado
  4. Nevada
  5. Arizona
  6. New York
  7. Hawaii
  8. Connecticut
  9. Oregon
  10. Massachusetts

Yep, California is No. 1 on this list, and it’s far ahead of any of the others. According to this report, California has 528 megawatts of installed solar power, New Jersey, the next closest state has only 70. So let’s take a closer look at California. This state is definitely in a naturally sunny part of the country. It also has strong solar incentives.

More Resources

If you’re considering installing solar panels at your home, there are many online resources where you can find more information. Here are a few to get you started. And to learn more about renewable energy where you live, check out our recent article The Best States for Wind Power.


Additional Resources:

  • American Solar Energy Society
    This organization is home of the magazine Solar Today, and offers many online resources for learning more about solar power.
  • National Renewable Energy Laboratory (NREL)
    Find information on solar power basics, as well as news on the latest research.
  • Real Goods
    This solar retailer provides detailed information on different solar products. Check out the site’s online version of the Solar Living Sourcebook.

Are there people installing solar power in your community? What are the solar incentives like in your part of the world? Share your thoughts by posting a comment below.

A PV array in Arizona — one of the best places in the United States for generating solar power.