US installs record solar capacity as prices keep falling

The annual analysis of solar energy in the US was released this week. It found that nearly half of the generating capacity was installed in the US during the first half of the 21st century. It's now cheaper to build and operate a solar plant than it is to buy fuel for an existing natural gas plant.

The Inflation Reduction Act contains many incentives and tax breaks that should increase solar's advantages in the future.

Solar, by the numbers

The US added over 12 gigawatts of new capacity last year, bringing the installed capacity to over 50 gigawatts. About a third of the total capacity went online in Texas. Solar accounted for 45% of the new generating capacity added to the grid last year.

Figures show how much energy solar supplies grew. Massachusetts and Vermont get more than 15% of their electricity from solar power, while California gets 25% of its electricity from the sun.

Falling costs have been the driving force behind solar's expansion. Since 2010, the price of building a solar plant has fallen by over 75% according to the DOE. The average price for each watt of capacity in the year 2021. Projects over 50 kilowatts cost 20 percent less than those under 20 kilowatts.

It's becoming more economical to build large facilities in states that don't get as much sun because of the drop in prices. The average incoming energy at newly constructed facilities has gone down over the past several years.

The capacity factor is calculated by dividing the amount of energy produced at a facility by the maximum energy it could have generated if it were open all day. The US had a median capacity factor of 24 percent, but there were outliers that ranged from 9 percent to 35 percent. The spread may become more pronounced as prices continue to fall.