US SOLAR TRACKER: Solar leads US clean energy additions in Q3, adding 7.525 GW

Solar led the US in third-quarter 2024 clean energy additions, making up 62.5% of all installations, with solar generation output up in all regions.

The US added 7.525 GW of solar capacity in Q3, up 6.9% from Q2 and jumping 34.3% year on year, according to data from S&P Global Market Intelligence. Thirty-eight states contributed to solar capacity additions in Q3.

Nearly 60% of planned capacity additions in the second half of 2024 are expected to come from solar at 25 GW, according to the US Energy Information Administration.

"If utilities add all the solar capacity they are currently planning, solar capacity additions will total 37 GW in 2024, a record in any one year and almost double last year's 18.8 GW," the EIA said.

Texas leads in solar capacity

For a second consecutive quarter, Texas led the US in solar capacity with 23.924 GW, or 20.5% of the US total, according to S&P Global Market Intelligence data. Texas also added the most solar capacity in Q3 with 2.642 GW, or 35% of all US additions. The state's solar capacity has climbed 72% from a year ago and is up 12.4% from Q2.

The Electric Reliability Council of Texas, which manages the flow of electric power for about 90% of the state's electric load, currently has 29.058 GW of cumulative operational solar capacity and expects that to reach 38.793 GW by the end of 2025 and 55.057 in 2026, according to a report of monthly capacity changes by fuel type.

Arizona added the second most solar capacity in Q3 at 585 GW, or 8% of US additions, according to S&P Global Market Intelligence data. The state ranks sixth for total solar capacity.

Oklahoma had the biggest quarter-on-quarter jump at 247.4% after adding 120 MW in Q3, bringing its total solar capacity to 169 MW, according to S&P Global Market Intelligence data. The state ranks 42nd in the US for solar capacity.

In total, three states have over 10 GW of capacity, 19 states have between 1 GW and 10 GW, and 27 states have less than 1 GW. The only state without any solar capacity is North Dakota and the state has no projects in the pipeline.

Project pipeline totals 47.6 GW

There is roughly 47.6 GW of solar capacity under construction or in advanced development across the US, according to Market Intelligence data. The majority of that is in Texas with 12.718 GW, followed by California with 3.568 GW and Ohio with 3.051 GW. Rounding out the top five are Illinois with 2.615 GW and Indiana with 2.444 GW. Forty other states have over 23.2 GW combined under construction or in advanced development.

CAISO currently has 20.093 GW of solar capacity, which accounts for 62.8% of all of its installed renewable resources, according to CAISO latest Key Statistic report.

Looking ahead, CAISO has nearly 105 GW of clean energy projects in its generation queue, including almost 12.5 GW of solar projects that have executed interconnection agreements. Of that amount, 1.437 GW have online dates in 2024, 4.4 GW in 2025 and 1 GW in 2026. In addition, there are 12.3 GW in the queue with solar listed as a secondary fuel that have executed interconnection agreements. Of that amount, 675 MW have online dates in 2024, 5.4 GW in 2025 and 2.8 GW in 2026.

Solar generation output

California ranks second in the US for solar capacity with 21.808 GW, or 18.7% of US total capacity, according to S&P Global Market Intelligence data.

The California Independent System Operator solar generation output increased 24% year on year to average 177.9 GWh/day in Q3, the most across the US, according to CAISO data. The PJM Interconnection had the biggest year-on-year increase at 64%, averaging 55.4 GWh/d, according to PJM data.

CAISO had the most solar market share across the US, averaging 25.4% of its total fuel mix for Q3, an increase of 5.4 percentage points from a year ago, according to CAISO data.

Looking ahead, solar output across the Lower 48 states is forecast to average 23.01 GW in Q4, down 21.6% from Q3, according to S&P Global Commodity Insights.

Prices down in ERCOT on year

Amid significant capacity growth, ERCOT solar capture prices saw the most notable year-on-year declines in Q3, continuing the Q2 pricing downtrend. Greater solar generation output, accompanied by lower wholesale electricity prices, served to dampen solar capture pricing levels in the ERCOT service area.

In the region's day-ahead power market, on-peak prices across the North, South and West Hubs plunged 82% to 83.1% year on year in Q3, equivalent to drops of approximately $145/MWh to $154.25/MWh, compared to the same period a year ago, according to ERCOT data. As a result, power prices at the three hubs averaged between $31.25/MWh and $32.75/MWh, according to data from Platts, which is part of S&P Global Commodity Insights.

ERCOT solar prices closely tracked wholesale power price movements. North Hub on-peak day-ahead locational marginal prices plummeted 84.8% from year-ago levels to average about $26.75/MWh in Q3. Similarly, West Hub averaged approximately $26.50/MWh, sinking 84.7% on the year, while South Hub fell 83.5% to nearly $27.75/MWh. Solar prices followed the Q2 trend and remained above $0/MWh but fell to the single digits early September. The highest Q3 values were recorded Aug. 6, as solar prices across the three main generation hubs paced in the $80s/MWh, compared to the quadruple-digit prices seen in late August 2023.

CAISO also experienced lower year-on-year solar capture prices alongside their spot power counterparts. SP15 saw the most considerable on-peak day-ahead LMP declines, tumbling 37.6% on the year to average $41/MWh, according to CAISO data. ZP26 followed with a 29.9% decrease to $36.75/MWh, while NP15 was down 24.4% to around $43.25/MWh.

CAISO solar pricing mirrored the wholesale power trend, as SP15 fell 39% from the year-before average to around $28.75/MWh in Q3, according to Platts data. ZP26 solar slumped 36% to average around $25.50/MWh, while the NP15 price was down 29.4% to $34.50/MWh. The SP15 solar capture price only fell below $0/MWh three times in Q3, compared to 63 times in Q2. Likewise, ZP26 slipped below zero four times, while NP15 remained in positive territory. Solar prices in NP15 and SP15 saw highs in the $70s/MWh, while year-ago highs were recorded at approximately $176.25/MWh and $197.25/MWh, respectively.