rooftop solar projects size

Originally published on PV Solar Report

There’s been a lot of talk this week about the Ivanpah Solar Electric Generating Station, which has officially begun generating electricity. The plant’s primary owners are BrightSource Energy, NRG Energy, and Google.

NRG Energy, Inc. (NYSE: NRG), through its wholly owned subsidiary NRG Solar, LLC, announced yesterday that the plant is now operational and delivering solar power to California customers. The largest solar thermal plant in the world, the huge solar farm covers about five square miles of federal land in the California desert. About 350,000 large mirrors reflect sunlight onto boilers that sit on top of three massive towers. The extreme heat turns the water into steam, which is fed to steam to turbines.

At full capacity, the plant can produce 392 MW of solar power, enough electricity to power about 140,000 homes a year.

Tom Doyle, president of NRG Solar, said in a statement, “Cleantech innovations such as Ivanpah are critical to establishing America’s leadership in large-scale, clean-energy technology that will keep our economy globally competitive over the next several decades. We see Ivanpah changing the energy landscape by proving that utility-scale solar is not only possible, but incredibly beneficial to both the economy and in how we produce and consume energy.”

Reactions to the plant’s opening have been mixed. It does help with California’s goal of producing 33% of its energy from renewables by 2020. And at full capacity, it can avoid 400,000 metric tons of CO2 emissions a year. Ivanpah’s dry-cooling technology is a bonus, given California’s current drought.

U.S. Energy Secretary Ernest Moniz has touted the plant’s economic and environmental benefits. And Rhone Resch, president of the Solar Energy Industries Association, called its opening "a dawn of a new era in power generation in the United States."

However, the plant has been the target of some criticism for its adverse environmental effects. It covers five square miles of habitat for desert tortoises and other creatures, and it generates so much heat that it’s frying birds who fly through the area.

Some see it as both a success story and a “cautionary tale” involving the tradeoff between environmental benefits and the risk of compromising fragile land.

Others think more of these large plants won’t be built for economic reasons -- and that we may be at a transition from big solar to rooftop installations. One reason given for this is that California doesn’t need more of them to meet its 2020 target.

But although there aren’t currently more plants like this in the pipeline, California and other western states are likely to increase its renewable energy targets. In addition, the technology has now been proven. And finding economies of scale from more projects being built would help with this expensive technology. According to GTM Research, that could adds up to possibilities for more plants like these, if storage options improve.

They acknowledge, though, that there will be competition from solar PV, which is already shifting demand to smaller projects.

Smaller can still be big. Utilities like Duke Energy are developing solar projects 5 MW or bigger. And some of those same utilities are not being friendly to smaller rooftop installations.

Still, rooftop solar is popular. And with groups of all political stripes now fighting for it, we can expect to see a lot more solar on roofs in the U.S. The question is what the mix will be when it comes to large and small installations -- and who will own and control that power.

Fasten your seatbelts, it’s going to be a bumpy ride!

Photo Credit: Solar Project Size/shutterstock