Some northern states added as much small-scale PV per capita as the top states in the Southwest, taking advantage of solar irradiance in northern states that’s about 70% as high as that in the desert Southwest.

From pv magazine USA

Solar contractors built 5.4GW of small-scale PV installations across the US in 2021, a 1GW increase over 2020. More than half the added capacity came in the “ten sunniest states” in the Southwest and West.

The US Energy Information Administration reported the data, and counts a PV installation smaller than 1MW as small-scale.

Colorado added the most small-scale PV last year relative to its population, adding 45 watts of capacity per capita. Close runners-up were Arizona, California, Maine, Rhode Island, Vermont and Nevada, all adding about 40 watts per capita.

Twelve states added less than one-fifth of that amount of small-scale PV per capita in 2021, and ten more states added less than one-tenth of that amount. That’s despite having good solar potential, as nearly every state has at least 70% of the solar irradiance found in the desert Southwest.

Hawaii maintained its commanding lead in the installed base of small-scale PV per capita, reaching 521 watts per capita. California, Massachusetts and Arizona reached more than half of that amount per capita, while Rhode Island, Vermont, New Jersey and Nevada all had more than 200 watts of small-scale PV per capita.

State data and regional totals are provided below for the Southeast, Northeast, Midwest & Northern Tier, and the “ten sunniest states” in the Southwest and West.

Southeast

The District of Columbia and Florida had the greatest small-scale PV additions per capita. The region added 666MW of small-scale PV overall.

Northeast

Maine, Rhode Island and Vermont had the greatest small-scale PV additions per capita. The region added 1.07GW of small-scale PV overall.

Midwest & Northern Tier

Illinois and Idaho had the greatest small-scale PV additions per capita. The region added 720MW of small-scale PV overall.

Ten Sunniest States

Colorado, Arizona, California and Nevada had the greatest small-scale PV additions per capita. The region added 2.9GW of small-scale PV overall.