A neutral observer has also given the Stirling solar design a good review. "This is a very high efficiency system," says Frank Wilkins, solar thermal team leader in the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy. "It's modular and has low water consumption, which is critical in desert areas. Of all the solar energies of the moment, this is at the top...You have to figure, this exercise is going to get [Stirling Energy Systems] more competitive in the energy market," Wilkins says.

Despite his optimism, though, Wilkins also wonders how easily the system would translate into a utility-sized operation.

"Even 40-dish systems haven't been built before, so there's a lot that hasn't been scaled to large systems," says Wilkins. In particular, he points to unknown operation and maintenance demands, as well as cost limitations.

"[Cost] been a sticking point with the other thermal technologies I work on that use solar heat to produce electricity [like heliostats]," Wilkins says. "The cost has to come down, whether through research breakthroughs or industries deploying the system."

Producing enough energy to offset the cost is what Stirling Energy Systems hopes to accomplish with its SCE deal, since high-volume fabrication should drop costs. The Department of Energy has stated that the prototype dishes at Sandia cost $150,000 to build; Stirling has estimated that large-scale production could bring down the cost to under $50,000 per dish.

Although it will provide environmentally friendly energy, the Stirling project will still make a mark on the Mojave landscape, covering as much as 4,500 acres when completed. Daniel Patterson, a desert ecologist with the Center for Biological Diversity, wants to be sure concerns for nativen wildlife are also addressed as planning proceeds. Parts of the desert are home to endangered animals like the desert tortoise, whose habitat has become encroached upon by mining, development and livestock grazing.

"We want to be very supportive of curbing fossil fuels," Patterson says, "but citing the actual location of the projects is important."

Stirling CEO Bruce Osborn says that their concerns will be addressed. "We're looking at a combination of Bureau of Land Management and private land, and we will certainly have to go through environmental studies to be sure it's good with the flora and fauna," Osborn says.

Osborn also reiterates that the system should bear less impact on the environment than other existing energy production methods: "the Stirling system takes less land than other solar systems, and requires minimal land grading. Plus, there are no toxic chemicals, and we use minimal water -- only a little to wash the mirrors every month...From our standpoint, we're very enviro-friendly."

In April at a DOE workshop (see links in Notebook), top solar scientists from academia and industry assessed the state of solar research. According to their findings, while solar power is improving, significant technological breakthroughs are still needed before it makes a dent in carbon-based fuel consumption.

"We need to double worldwide energy production by 2050," said Dr. George Crabtree, the Director of Materials Science at the Argonne National Laboratory in Illinois, who co-chaired the meeting, adding that in the long run, though, our society will "need something other than fossil."

To Crabtree, Solar is the most promising energy source because of its sheer volume: the sun provides more energy to the Earth in one hour than all the energy consumed by the planet in a year. Nevertheless, solar remains largely untapped, making up around one millionth of the world's total electrical supply, according to the report.

"If you want to have solar 50 years from now, you have to invest in doing it dramatically better," says Crabtree, "because the learning curve [for scientists and engineers] is steep."

Crabtree hesitates to put a figure on how much he thinks federal funding should increase, but asserts that current levels are not nearly enough. Current estimates put federal funding for solar research at approximately $10 million, while industry experts estimate the need for at least $30 million annually to support research.

Although Crabtree doesn't see Stirling Energy Systems' dish technology as necessarily a technological revolution, he does think it's encouraging to see industry players adopting solar energy.

"Making it work, putting it out in the field -- you might call that a cultural advance," says Crabtree.