US adds 530 MW of new solar capacity in October

The United States added a total of 530 MW of new capacity in October, all of it generated entirely by solar energy projects.

According to a report published this week by SNL Energy, 510 MW of the total 530 MW of capacity that came online in October were installed in the Western Electricity Coordinating Council (WECC) region. The WECC oversees the bulk electric system in the geographic area known as the Western Interconnection, which includes all or parts of the 14 western U.S. states, two Canadian provinces and the northern portion of Baja California, Mexico.

The SNL Energy report does not include capacity from the installation of rooftop photovoltaic systems on homes and businesses, however. (In California, for example, residential and non-residential rooftop solar installations backed by the California Solar Initiative accounted for an added 19.5 MW in October.)

The largest new project to go online in the U.S. was the 139 MW (AC) Campo Verde Solar PV 1 array in Imperial County, California. First Solar, which constructed the Campo Verde Solar farm, sold the project to Southern Company subsidiary Southern Power and Turner Renewable Energy in April. Sempra Energy subsidiary San Diego Gas & Electric Co. will buy the entire capacity of the facility under a 20-year power purchase agreement (PPA).

Abengoa SA subsidiary Arizona Solar One’s solar thermal units at Solana Generating Station in Maricopa County, Arizona, were the second and third-largest units completed in October. With a combined 250 MW (125 MW each) of capacity, the plants accounted for most of the total completed capacity during the month, according to the SNL Energy analysis.

The facility, built at an estimated cost of $2 billion, is the first U.S. plant to use a thermal energy storage system, allowing it to store energy and dispatch electricity when needed over a six-hour period. Arizona Public Service Co. has contracted for its entire output under a 30-year PPA.

Commenting on the new capacity installed in October, an article in the U.S. magazine The Atlantic wrote that while completion dates for power plants can be random, the fact that solar supplanted coal and natural gas in October was noteworthy.

While the article points out that 530 MW is “not a huge amount of power – at peak output 530 MW is what a medium-sized natural gas-fired power plant would generate," writer Todd Woody adds that it is "a clear sign that solar is no longer a niche play – especially when you consider that the October’s numbers don’t include the installation of roof photovoltaic panels on homes and businesses."

Citing a recent report by NPD Solarbuzz indicating planned PV installations in the United States have increased 7% to 43 GW over the past year, Woody says October’s solar statistics are likely to become typical.