Ace is putting his reputation on the line in touting multiple scientific breakthroughs that he says can harness the suns diffuse rays into energy that is cheap and reliable enough to compete with other fuel sources. If so, he has conquered a challenge whose answers have eluded scientists and engineers around the world.
There are obstacles everywhere, enough so that a senior Energy Department official told McClatchy last year that the agencys solar program is still in its infancy despite billions of dollars in expenditures over more than 35 years.
For starters, the energy in sunshine is dilute, unlike the highly concentrated energy in oil or coal, and so it takes a lot of area to absorb solar energy.
Collecting those rays is tricky, because the Earths rotation makes it difficult to design mirrors or receivers that can track sunlight for more than a few hours per day.
Even rotating mirrors, called heliostats, cant collect solar energy on cloudy days.
There are also the radiation losses from a hot receiver, the geographically variable weather that leaves some regions with less sunshine and the critical need for massive storage.
The currently preferred storage method is to transfer solar energy to tanks of molten salt. So far, thats proved too expensive, accounting for 25 percent of a power plants cost just to store eight to 12 hours of energy, only a few hours for higher-temperature plants. As a result, pilot plants built in the sunny Southwest under Sandias auspices require backup from conventional fuels and wouldnt be viable without federal subsidies. To make matters worse, fierce competition from plants powered by cheap, Chinese-made photovoltaic panels have undercut the financial models behind solar thermal plants, leading to bankruptcies and canceled plans.
Ace said that, because his solar traps can collect energy at ultra-high temperatures, the storage issue all but disappears. The energy can be stored for weeks in silicon dioxide (pure sand) or other cheap materials and extracted via heat exchangers as needed, he said, meaning that reliable solar power plants could be built almost anywhere, though it would be more expensive in cloudy regions.
As for finding the space to mount enough solar traps atop homes and businesses, Ace estimates that there are well over 7,000 square miles of residential and commercial rooftops in the United States.
A solar energy breakthrough of the magnitude that Ace describes not only would be momentous for its scientific merit, but also for its timing, amid global warming concerns and projections of a looming worldwide energy crisis, despite the U.S. oil and gas revival. The world population is projected to surge past 8.5 billion people in the next 20 years, even as energy companies are drilling for oil in increasingly harsh conditions.
An all-out shift to solar energy, a process that would take decades even on a fast track, could avert economic tumult and potential military conflict if affordable fossil fuels became scarcer.
While solar power wouldnt on its face address the long-term need for liquid fuels to replace oil, Ace said that once a region amassed huge stores of thermal energy, it could be used to create other forms of energy, including liquid fuels. For example, Sandia researchers developed a way to use high-temperature solar energy to break down carbon dioxide from the air into carbon monoxide, a key building block in making synthetic hydrocarbons whose greenhouse gas emissions would be carbon neutral.