BrightSource Energy is a leading solar thermal energy company. In California, it’s in the process of planning and building some of the largest solar thermal power plants in the world. (For more on its technology, see the last paragraph of this post. For more background, check out our BrightSource Energy page.)

Yesterday, the company announced that it is adding “its SolarPLUS thermal energy storage capability to three of its power purchase agreements with Southern California Edison (SCE).” It now has two solar thermal power plants scheduled to be finished and delivering energy in 2015, and three, with storage, scheduled to deliver electricity in 2016 and 2017. (And, BrightSource — with partners NRG Energy, Google, and Bechtel — are building a 126-megawatt plant for Southern California Edison at the Ivanpah solar project in southeast California).

Energy Storage Benefits

“By adding storage to its solar thermal power plants, BrightSource is able to further reduce the total cost of energy by increasing its capacity factor — how much power a plant produces over a year — extending the production of electricity into later parts of the day when it is most needed by utilities,” the company notes.

With the added storage capabilities, BrightSource doesn’t have to build an extra 200-megawatt solar power station (so, it will build six such power stations instead of seven). This will also save approximately 1,280 acres of desert land and will save utility customers money.

The added storage also cuts the need for additional power plants, including more costly coal and nuclear plants, and avoids variability and integration costs that solar PV and wind power face.

“With these agreements, we’re demonstrating that power tower technology is not only advancing the solar thermal industry, but that utility-scale solar generation can be both cost effective and reliable,” said John Woolard, President and CEO of BrightSource Energy.

Clean Energy Mix Moving Forward

Some argue that the benefits of rooftop PV beat the benefits of solar thermal power plants. Some argue wind power beats them both. Personally, I’m of the opinion that we need them all of them at this point, so I’m happy to see BrightSource and California moving forward with these pioneering projects.

More on BrightSource’s power plants:

“A BrightSource power tower solar thermal system uses a field of software-controlled mirrors called heliostats to reflect the sun’s energy to a boiler atop a tower to produce high temperature and high pressure steam. The steam is used to turn a highly efficient steam turbine to produce electricity. When storage is added, the steam is directed to a heat exchanger, where molten salts are further heated to a higher temperature, thus efficiently storing the heat energy for future use. Later, when the energy in storage is needed, the heat stored in the molten salts is used to generate steam to run the turbine.”

Thanks to one of our great readers for the story tip!

Image via BrightSource