Solar Power in Space Can Power the Planet

The 21st century is full of examples of sci-fi becoming just plain science, and none is more startling than PowerSat Corporation's determination to float solar panels in space to trap sunlight and beam the energy back to earth in the electromagnetic equivalent of radio waves.

It's an idea ahead of its time, but solar radiation is five times stronger than any place on earth because all the atmospheric particulates and carbon dioxide don't reduce solar inputs. There are also no clouds or storms to worry about; thus the Sun transfers nearly 100% of its energy to the solar panel.

There are, however, obstacles to space-based solar power, one being getting the panels into the ionosphere without spending a gazillion dollars, and the other involves wiring the array.

PowerSat recently filed a patent meant to solve both problems. Of course, we can't give you the precise details, but it seems the company will build a solar array and use the power from that (code name SPOT, or Solar Power Orbital Transfer) to launch some (half, one-quarter?) of the panels into orbit via electronic thruster technology - a move that reportedly saves $1 billion.

The second solution is similar to cloud computing, or linking remote desktops to create a more powerful computer. Reportedly, PowerSat's system - code name Brightstar - could connect as many as 300 smaller arrays into one huge one, convert the direct-current (DC) energy into radio-frequency energy, and beam that down to earth to be converted into electricity at the substation. Scotty is not part of that plan, however.

PowerSat says the inventions could save $1 billion of the estimated cost of putting 2,500 megawatts of solar panels in space, but doesn't say how much money is still required to accomplish the feat. A 2007 Pentagon report suggests $1 billion per megawatt, with the project technically doable by 2016. Still, if one does the numbers, the distance to grid parity remains enormous. At least on earth, we're getting close to parity, with the U.S. aiming for $.10 cents in 2010 and Europe, with its much higher utility costs, expecting parity within a decade.

Parity is the point at which renewable energy technologies like solar and wind cost customers the same amount per kilowatt hour as traditional energy sources like coal and oil.

PowerSat isn't the first company looking to space for solar energy. Two months ago, Solaren announced a contract with California-based Pacific Gas & Electric (PG&E), which has promised to buy its entire output of space-based solar power - 200 megawatts by 2016.

Solaren, now 10 years old, remains confident it can meet that deadline. PowerSat, a mere eight years old, seems equally confident of its expertise. Is it the optimism of youth, or do these guys know something that has eluded the rest of us science neophytes?

Time will tell, perhaps in as little as three years, when PowerSat launches a low-earth-orbit, 10-kilowatt demonstration project at a cost of about $100 million, followed in 2015 by a prototype. If success ensues, the company will seek out a partnership with a utility or the government, or offer an IPO to generate the funds needed for step two. Projections estimate the cost of a 2.5-gigawatt project at about $4.5 billion.