Environment Forum

Defense Department to test concentrating photovoltaic technology

The United States Department of Defense has signed a deal with Silicon Valley startup Skyline Solar to test its concentrating photovoltaic technology at military bases in California and Texas.

The Pentagon, one of the nation’s biggest consumers of energy, has emerged as a driver of new green technologies in an effort to wean itself of imported oil, reduce its carbon footprint and improve national security.

Earlier this year, Navy Secretary Ray Mabus pledged that within a decade the U.S. Navy would obtain half of its energy on land and sea from renewable sources. Back in 2007, the Air Force commissioned SunPower to build what was then the country’s largest photovoltaic power plant at the Nellis Air Force Base in Nevada.

According to the agreement announced Tuesday, Skyline will build a 100-kilowatt solar array at Edwards Air Force Base in Southern California and another 100-kilowatt system at Fort Bliss near El Paso, Texas.

At first glance, the company’s power plants resemble solar thermal parabolic trough installations that deploy long rows of mirrors to heat tubes of liquid suspended over the arrays to create steam that drives an electricity-generating turbine.

Skyline’s system, however, is a purely solid state. Each 120-foot-long trough concentrates the sun on photovoltaic modules attached to the edges of the arrays. That boosts the solar cell’s electricity generation as does a tracking mechanism that allows the arrays to follow the sun throughout the day.

Such concentrating photovoltaic systems — which Skyline calls “high gain solar,” or HGS — have been a niche market due to their relatively high costs. But as solar cell prices decline and solar thermal projects get bogged down in environmental disputes, they have become increasingly attractive as they can be built near utility substations and plugged into the grid without the need to build expensive new transmission systems.

Report: U.S. utility-scale photovoltaic industry set to boom

With NRG Energy’s announcement on Tuesday that it will invest $450 million investment in a California photovoltaic project, the New Jersey-based power provider has pledged a total of $750 million for big solar plants in the past two months.

A new report from GTM Research indicates why NRG sees such sunny prospects for the solar business. According to the researchers, utilities in the United States already have signed contracts for 5,400 megawatts’ worth of photovoltaic power plants that will be built by 2014 with another 10,100 megawatts in negotiation.

The U.S. utility-scale photovoltaic market is expected to grow from $1 billion in 2010 to $8 billion by 2015, the report said.

“The global PV industry is increasingly turning its attention toward the U.S. utility PV market as a driver of global demand over the next five years,” the report’s authors wrote. “Indeed, conditions appear right to support massive growth.”

That growth is being driven by a 50 percent fall in the price of photovoltaic modules since 2009 as well as state mandates that require utilities to obtain a certain percentage of their electricity from renewable sources.

The price of natural gas, though, will play a critical role in the competitiveness of solar power plants.

Nevada’s solar building boom

Over the past three months, California regulators have made headlines by licensing seven huge solar thermal power plants that would generate nearly 3,500 megawatts of electricity if all were built in the Southern California desert.

Garnering far less attention is a solar building boom that is getting under way in neighboring Nevada, which eventually could build plants that send electricity to California as well.

In October, Interior Secretary Ken Salazar approved the  Silver State North Solar Project, a 60-megawatt photovoltaic power plant to be built by First Solar on 618 acres of government-owned land near the casino town of Primm 40 miles south of Las Vegas.

And earlier this month Salazar signed off on a 500-megawatt solar thermal complex called the Amargosa Farm Road Solar Energy Project to be built by Solar Millennium, a German developer, some 80 miles northwest of Las Vegas. Several other large solar projects are currently under review by the United States Bureau of Land Management.

Although state environmental review of big solar power plants in Nevada is far less extensive than in California, the Solar Millennium project initially caused an uproar in Amargosa Valley, a hardscrabble town of sun-beaten mobile homes.

While some residents welcomed the prospect of 1,300 construction jobs coming to a county battered by recession, others worried about the project’s impact on their water supply.

Utility makes big bets on solar technology

As solar panel prices have plummeted over the past year, photovoltaic power plants have become a more attractive option for utilities under pressure to meet renewable energy targets.

Case in point: Late last week utility Southern California Edison announced it had signed contracts for 239.5 megawatts of electricity to be generated by 20 small-scale photovoltaic farms.

“Photovoltaics are definitely more cost competitive than they were just a couple of years ago,” said Mike Marelli, director of contracts for renewable and alternative power at Southern California Edison. “We’re seeing just a wild response to our solicitations for projects.”

The utility has inked deals in past years for huge solar thermal power plants that can generate 500 megawatts or more. But those projects — which focus large arrays of mirrors on liquid-filled boilers to generate steam that drives electricity-generating turbines –  need vast stretches of desert land.  Transmission lines must often be built or upgraded to carry the power to coastal cities.

The photovoltaic farms, ranging in size from five megawatts to 20 megawatts, are designed to be built near existing transmission lines or substations and plugged into the grid. And in California, for instance, photovoltaic power plants do not undergo the extensive environmental review required of big solar thermal projects, meaning they can be built much more quickly.

In the power purchase agreements reached last wee, Southern California Edison also for the first time placed bets on a technology known as concentrating photovoltaics – -CPV — signing contracts for 28.5 megawatts of electricity to be generated by four projects using technology supplied by Amonix,  a Seal Beach, Calif., company.

Feinstein wants her desert and solar, too

California Senator Dianne Feinstein is fuming over a federal plan to use some Mojave desert lands to develop solar power plants and wind farms.

In a letter to Dept. of the InteriorSecretary Ken Salazar, Feinstein said she planned to introduce legislation that would protect the former railroad lands, thereby preventing the federal government from leasing them to renewable energy project developers. The 600,000 acres in question were acquired by and donated to the government’s Bureau of Land Management between 1999 and 2004 for the purpose of conservation.

“I have been informed that the BLM now considers these areas open for all types of use except mining.  This is unacceptable!” Feinstein wrote in a March 3 letter made public last week.

Feinstein, a supporter of renewable energy, said many of the desert lands being considered for solar and wind development are unsuitable.

“It is critical that these projects move forward on public and private lands well suited for that purpose,” Feinstein wrote.  “Unfortunately, many of the sites now being considered for leases are completely inappropriate and will lead to the wholesale destruction of some of the most pristine areas in the desert.”

Earlier this month, the U.S. Interior Department said it would identify zones on public lands where the department can act rapidly to create large-scale production of solar, wind, geothermal and biomass energy. Building and consuming more clean, renewable energy is a cornerstone of the Obama administration’s energy and economic policies.