Wind turbines clustered on hilltops near Tehachapi. (Photo: Sasha Khokha)

This time it’s Terra-Gen’s multi-phase wind project in Kern County, known as the Alta Wind Energy Center.

Google’s clean-tech investment arm will reportedly invest $55 million in the project, being built near Tehachapi.

Bill Weihl, Google’s green energy “czar,” told me in an interview last year that the company would support clean energy technologies with two main attributes; global scalability and the potential to become cost-competitive with coal power. In a 2010 interview with the New York Times, Weihl said he thought Google’s “culture of innovation” made it a good fit with renewable energy development.

Google has now made substantial investments in wind, solar and geothermal projects, in and around California, as well as bankrolling an ambitious scheme to build a connective spine connecting offshore wind projects along the Atlantic coast.

A cluster of wind turbines in Tehachapi Pass marks California's early commitment to wind energy. (Photo: Craig Miller)

Wind power generators added nearly 40% to their total capacity in the US last year, as several states blew past California, according to a new report from the Department of Energy’s Lawrence Berkeley National Lab. According to the tally, four states now generate more than 10% of their total electricity (excluding exports) from wind.

Texas is the undisputed leader in the wind race, installing nearly 2,300 megawatts of capacity last year alone. Other Midwestern states such as Indiana, Iowa, the Dakotas and Minnesota have also been aggressive installers of wind farms.

California ranks third in total wind capacity (2,798 MW) but only 12th in the

Turbines on the Maple Ridge wind farm in upstate New York. (Photo: Craig Miller)

volume added last year. Even states like Oregon and New York, where expansion of wind farms has been controversial, added more capacity last year. California also ranks relatively low in the percentage of total electricity from wind, at just 3.4%, though the state is poised to make a major move with the recent groundbreaking for Terra-Gen’s Alta Wind Energy Center in Kern County.

One of the report’s co-authors, Mark Bolinger, explained in an email that transmission constraints and California’s exhaustive (some say exhausting) site permitting process are factors in the state’s wind slowdown, “In addition, California’s wind resource tends to be concentrated in a handful of  ‘wind passes’ (e.g., Altamont Pass, San Gorgonio Pass, Tehachapi, etc.), all of which already contain lots of wind turbines built since the 1980s.” Bolinger adds that ideally, many of those older projects should be “repowered” with newer turbines.

The report also notes that while the US still has the most total capacity installed, China has leapfrogged the US in the pace of its build-out. Also, the US currently has no offshore wind generation, a mainstay in places such as Scotland and Denmark. Though several projects are in the works (the report makes note of “accelerated activity”), little of that is happening on the west coast. Plans for major wind installations in Lake Ontario have encountered public resistance from residents in upstate New York, and the prolonged battle over the Cape Wind project off Massachusetts is now the stuff of legend.

Despite the glacieresque pace of offshore projects, the reports says that for two years running, wind has outpaced all other new generation, except for natural gas.

The entire 88-page wind report, a shorter summary and PowerPoint presentation are all available as PDF downloads at the Lab’s website.

Also today: Oakland-based BrightSource Energy announced that a siting committee at the California Energy Commission has recommended moving forward with the company’s Ivanpah solar plant. Brightsource describes the project as the “largest solar energy project in the world” and claims that if approved by the full commission, it will nearly double the nation’s total output from solar-thermal arrays.

Follow the KQED News multimedia series: “33 x 20: California’s Clean Power Countdown,” with radio reports, blog posts and interactive features.

A solar-thermal array uses mirrors to concentrate sunlight. (Image: BrightSource Energy)

On a media call this week in which executives and investors from the solar industry stumped for extensions to key federal incentives, I heard Fred Morse of Abengoa Solar say that the company’s Solana project in Gila Bend, Arizona, will be, as described on the project website, “the world’s largest solar plant.” Later that same day, an email came in from Oakland-based BrightSource Energy, (not in response) touting its Ivanpah project as “the largest solar project in the world.” Similar terms have been used to describe Solargen’s proposed 4,700-acre photovoltaic array in San Benito County.

The power generation business has entered a new age of superlatives.

There are various ways of measuring size. The physical footprint of the plant could be one but usually such projects are ranked by their planned power capacity, in megawatts. BrightSource says Ivanpah will be about 400 MW. Peterson says that if Solargen isn’t forced to downsize the Panoche array to get it permitted, it would clock in at 420 MW (to put this in perspective, the twin reactors at PG&E’s Diablo Canyon Nuclear Power Plant are rated at more than 1,000 MW–each).

Part of the confusion may lie in the different technologies. Utility-scale solar projects can be either PV or “solar-thermal” arrays. The latter uses focused sunlight to make steam and requires fewer panels for the same output.

According to BrightSource CEO John Woolard, size matters. Woolard estimates that in order to stabilize atmospheric carbon at 450 parts per million (we’re at 392 and counting) by 2050, “Every day we have to build the equivalent – somewhere in this world – of a nuclear power-plant’s-worth of output of carbon-free energy. It’ll be a combination of wind, solar, some nuclear, maybe we’ll figure out carbon sequestration, but 1 gigawatt per day.”

In any case, new projects are being slated at such a pace that the answer to which is the biggest may be: “What day is it?”

It looks pretty big but PG&E's Vaca-Dixon PV array generates just 2 MW--and that's the strategy. (Photo: Craig Miller)

Meanwhile, some developers are taking the opposite tack. Last month, PG&E threw the ceremonial switch on its Vaca-Dixon solar array, just off I-80, west of Davis. It’s an example of what you might call “solar infill.” Built on 16,000 acres surrounded by farmland, the photovoltaic (PV) array generates just two megawatts of power for the grid. Eventually, though, the utility plans to build out enough PV patches to produce 500 MW (enough to power about 150,000 average homes in California); half on its own and half from contractors. All the arrays, however, will be two megawatts or less.

In the video clip below, PG&E President Chris Johns talks about the company’s newest solar mini-farm.

By the way, Terra-Gen Power announced this week that after lining up more than a billion dollars in financing, it will break ground next week on a 3,000-megawatt wind farm in Kern County. Once all five phases of the Alta Wind Energy Center are built, it would be, according to Terra-Gen, “the largest wind power project in the world”…of course.