A first of its kind data set from kWh Analytics ranking production at individual solar power plants around the country indicates that California and the Southwest still have the upper hand in solar energy output.

California in particular far outpaced any competition. Among the top 10 solar states by highest-performing projects, 43 of the 70 plants were located in California.

Those results are not entirely surprising, but MJ Shiao, global lead of renewables and emerging technology at Wood Mackenzie, said the transparency behind sharing the data is a boon to the industry. 

"While you can look at these results and say that they're pretty obvious (i.e., single-axis trackers in high-insolation areas produce best), I think the real accomplishment is having a single platform to host and compare real performance — and being willing to share that with the industry," he said. "More transparency into actual asset performance across multiple owners and project types is welcome and necessary to ensure that solar continues to actualize its promise as a long-term clean energy generation source."

KwH Analytics and partner the Solar Finance Council said the report could increase investor confidence in project finance, as well as offer operators and developers concrete benchmarks to meet industry standards.

“The solar industry has grown tremendously, and our understanding of asset performance must grow as well,” said Mike Mendelsohn, executive director at the newly formed Solar Finance Council. “This report provides investors critical insight on solar technology performance and can help lower the cost of capital for the broader solar sector.”

Areas favored in the rankings obviously get more annual sunlight than northern regions in the United States, and Shiao said he would have liked to see adjustments for insolation. A further breakdown by region did offer some insight on the top-performing projects located around the country. 

In the Northwest, Oregon claimed four of five top-performing projects. In the Midwest, Indiana came away with six of the 10 top-performing projects. And all of the top-performing projects in the Northeast were located in New Jersey.

KWh Analytics also divided the rankings between tracker and fixed-tilt sites, because trackers can increase a facility’s yield by 20 percent. 

According to the analysis, the top-producing tracker projects produced at least 2,180 megawatts-hours/megawatt peak, while the top fixed-tilt projects produced a minimum of just 1,500 megawatt-hours/megawatt peak. The use of trackers remains more common in the Southwest and South, offering those projects an edge in output.   

 Source: kWh Analytics

While the Southwest dominated in both tracker and fixed-tilt project output, the spread was more evenly shared with the South for fixed-tilt projects.

 Source: kWh Analytics

The report is the first from the Solar Finance Council, which announced its formation just last week. It cited a mission to lower the cost of capital and encourage new investors in the solar space. 

In the announcement of the group’s formation, Mendelsohn — previously of the Solar Energy Industries Association — said “the industry needs to find new and larger sources of capital, and to do so, improve investor confidence that solar assets produce energy and long-term cash flows as originally projected.”

The Solar Finance Council said it would help achieve these goals through research and data distribution, so it’s likely more partnerships are to come.

“To meet the extraordinary challenge before us, solar needs to be on every rooftop in the country,” said Mendelsohn in a statement. “That is going to require a lot of investment capital, as well as critical cost reductions through improvements in consistency and quality in project development. The SFC is designed to facilitate the cross-functional industry organization necessary to make that happen.”