[pagebreak:Cool Earth Breaks Ground on Prototype Plant]

Cool Earth Solar, a startup developing inflatable balloon-like solar concentrators, has broken ground on its first prototype power plant, CEO Rob Lamkin told Greentech Media.

Lamkin said the plant, near the company's offices in Livermore, Calif., will consist of a row of slightly different concentrators to try out the designs and prove out the technology. All together, the plant might have the capacity to generate "maybe a fifth of a megawatt or something" and will be a couple of acres large, he said.

The company hopes the project will help it gather the information it needs for its next project, a larger pilot project – about 11 acres large – intended to produce up to 1.5 megawatts. Lamkin said Cool Earth plans to start developing the second prototype project in the winter and bring it online early next year. 

"It's a very exciting time. It's one thing to be doing this on paper, and another to be installing on a field," he said. "We will know for certain in the next couple of months whether we're spot on or crazy or what. We'll build our prototype and prove [it works] and then it's off to the races to start deploying our technology."

If all goes well, the company will begin developing its commercial plants, expected to have the capacity to deliver 10 to 30 megawatts, next summer, he said. 

The news comes less than a week after another concentrating-photovoltaic company, SolFocus Inc., said it had completed its first commercial project, installing 500 kilowatts of concentrators in Spain (see SolFocus Completes Spanish Project, Eyes California).

Concentrating-photovoltaic companies have been raising good amounts of venture capital - $350 million since 2005, according to Greentech Media senior analyst Eric Wesoff (see Green Light posts here, here, here, here, here and here).

But some analysts remain skeptical about how well they will do as a group (see Which Concentrating Solar Companies Are Doomed?). Prometheus Institute President Travis Bradford expects them to make up only about 2 percent of the solar market in 2020 (see Concentrating Solar to Reach 18 Gigawatts by 2020).

Cool Earth has invented a technology that uses an inflatable Mylar balloon – made of the thin reflective plastic used in potato-chip bags – to concentrate sunlight into a receiver, at the top and center of the balloon, equipped with a solar cell to convert the light into electricity.

The balloons, about eight feet across, concentrates sunlight 400 times and directs it to a four-inch pattern of solar cells. The receiver is cooled by a system that runs cool water in and warm water out, and the balloons are connected to an air system that keeps the balloons inflated to the ideal pressure and size to keep the focal point at the center.

Simple software and a computer processor keep track of the air and water, while also measuring the power coming out of the cell and managing the mechanical tracking system that keeps the concentrators facing the sun, Lamkin said.  

The company estimates that its technology, fully installed, will cost a total of about $1 per watt when it begins building commercial plants next year. That compares with solar-thermal projects that claim about $4 per watt, Lamkin said.

"It's a huge difference in price," he said. "And this is not something we're saying will be there in five to 10 years. This is what we expect to build at our plants [for] next year."

The company already is negotiating power contracts with several utilities, Lamkin said.

"It's not going to be a problem for us to sell our energy because our price is right," he said. "Utilities want renewable energy now, and we have the advantage of being able to deliver to them next year, not five years from now."

Utilities in states with renewable portfolio standards, such as California, have been scrambling to sign on projects that could help them meet the requirements to get a certain percentage of their electricity from renewable sources by a certain date. But not every contract will result in successful projects and delivered electricity.

[pagebreak:Cool Earth: Continued]

Cool Earth intends to purchase multilayered solar cells from a manufacturer such as Emcore Corp. or Boeing Co.’s Spectrolab (it later plans to use silicon-based cells), and also will buy poles and anchors to hold its concentrators 10 feet off the ground, from other suppliers.

The company also plans to buy thin-film plastic, which Lamkin said is made in "huge quantities," with some 450 billion square feet produced last year alone. 

Each concentrator will be made from 10-foot-wide rolls of plastic films, one layer coated with aluminum, and one clear layer. Cool Earth won't make the concentrators itself, but it also won’t need to build a big factory to start making them. Lamkin said the mylar balloons can be produced via an automatic process on a 12-by-12 foot table.

A machine cuts the layers of plastic film into a circle, treats the material, glues it together and heats it up, he said.

"We don’t need to build a $100 million manufacturing plant," he said. "We will spend tends of thousands of dollars on the equipment to build the concentrators."

Cool Earth plans to build, own and operate its own solar projects and to sell the electricity to utilities. That means it’s taking on all of the risks of the technology performing as the company expects, but Lamkin said he's confident.

"We’re best suited to take the risk of owning and operating our plants because we developed the technology. But also, the technology is so simple. We’re not trying to build a whole series of mirrors and doing boilers and miles of mirror troughs. The technologies are breakthrough, but in terms of building and engineering, these plants are very straightforward. We’ve got a good handle on the risk."

Cool Earth was officially founded last year, but the core engineering team filed the first provisional patents for the technology about two years ago.

Eric Cummings, the company founder, came up with the idea for the technology by considering which materials are abundant enough to be of use in addressing the huge size of the energy problem.

"Whatever solutions we work on, they have to scale," Lamkin said. "Using that as a premise drove the science and engineering team to look at thin plastic. That didn’t come about because Cool Earth looked at all the other technologies and thought ’How can we do this different and better?’ but because we thought ’We need to deploy this over hundreds of square miles of land to capture that much sun. What kind of material can do it? Thin plastic.’ "

The company closed an angel round of approximately $1 million in 2007, when it also bought Radiant Energy, a power producer that developed geothermal, hydro and solar plants.

Lamkin, previously the chief executive of Radiant, took the top position at Cool Earth as part of the deal.

In February, Cool Earth announced that it had raised $21 million in its first round of financing from undisclosed investors (see Concentrating Solar Gets a Cool $21M).

The money will be enough to build the first two pilot projects, Lamkin said. Cool Earth will need to raise money for its first 10-megawatt commercial plant, he said, but doesn’t yet know what form that financing will take – equity, debt financing or some combination.

Cool Earth plans to use the revenue generated from early power plants to help finance the next ones, in an attempt to deploy its technology "on a massive scale" as soon as possible, he said.

"It’s not enough to have a really cute or clever design, to build a few kilowatts and pat ourselves on the back," he said. "We feel the problem is significant and severe, and anything that we do, we have to be able to scale and get there quickly and the price has to be right - the same price as fossil fuels today."