The United States is on the brink of a significant shift in its electricity generation landscape, with solar energy poised to overtake hydropower as the leading source of power by 2024, as forecasted by the U.S. Energy Information Administration (EIA) in its Short-Term Energy Outlook (STEO). This transformation is being driven by the sustained growth in both utility-scale and small-scale solar facilities.
A milestone was reached in September 2022 when, for the first time, the U.S. generated more electricity from solar sources than from hydropower facilities during a single month, as reported in the Electric Power Monthly. In that month, U.S. solar power, including both solar power plants and rooftop installations, produced approximately 19 billion kilowatthours (kWh), outpacing hydropower's 17 billion kWh.
The consistent growth in installed solar capacity has been the driving force behind this shift. Over the period from 2009 to 2022, solar capacity increased by an average of 44% annually, while hydroelectric capacity saw minimal growth, increasing by less than 1% each year. The EIA's STEO anticipates that in 2024, annual solar generation will surpass hydropower generation for the first time. This pattern is reminiscent of what was witnessed in 2019 when annual wind generation overtook hydropower.
The growth trajectories of U.S. solar and wind generation are mirroring each other, both closely tied to the expansion of installed capacity. Incentives like investment tax credits have played a pivotal role in promoting the growth of renewable generation capacity.
As of August 2023, the total installed solar capacity in the United States has exceeded 125 gigawatts (GW), comprising 80 GW of utility-scale solar and an estimated 45 GW of small-scale solar capacity. In contrast, hydropower capacity in the U.S. has remained relatively stable at around 80 GW for several decades.
While weather patterns have impacted hydroelectric generation through August this year, it's important to note that hydropower generation is contingent on seasonal hydrologic conditions and long-term weather trends. Solar and wind generation, despite also being affected by weather patterns, have demonstrated faster growth in generating capacity.
Hydroelectric generators possess reservoirs that can store water for electricity generation during periods of high demand or elevated prices, but this capacity is restricted by long-term hydrologic conditions and other complexities related to water rights and recreational usage. Nonetheless, hydropower remains a significant component in the hourly generation patterns, especially in regions like the Pacific Northwest.
