Moving Towards Space-Based Solar Power
Solar power is very green, and the great big fusion reactor in the sky generates more than enough energy for all of humanity’s needs. But if you put solar panels on the surface of the Earth, you have to deal with two big problems: 1) Solar energy bounces off the atmosphere, especially on cloudy days (see pic below), and 2) you don’t get power at night. Engineers have had a theoretical solution for both of these problems for a few decades: Put your solar collectors in geostationary orbit (22,300 miles/35,700 km) where they’ll get direct sunlight 24/7, and beam down the energy using microwaves. Progress has been slow so far, but Japan is shaking things up.
The Longest Journey Starts With a Single Step
Bloomberg is reporting that “Mitsubishi Electric Corp. and IHI Corp. will join a 2 trillion yen ($21 billion) Japanese project intending to build a giant solar-power generator in space within three decades and beam electricity to earth […] Japan is developing the technology for the 1-gigawatt solar station, fitted with four square kilometers of solar panels, and hopes to have it running in three decades”
They will be working on one of the essential technologies needed for space-based solar: Wireless energy transmissions.
A research group representing 16 companies, including Mitsubishi Heavy Industries Ltd., will spend four years developing technology to send electricity without cables in the form of microwaves.
The next step will be figuring out how to reduce the cost of putting all that material in space. This will probably mean cheaper and more efficient launchers, but also lighter solar panels and equipment.
While the project might sound like science-fiction now, it likely that the landscape will be more favorable in 30 years (strict carbon emissions caps will make clean energy more cost-competitive, for example).
But Won’t This be a Death-Ray From Space?
For those of you who are afraid that beaming down gigawatts of energy from space could be dangerous (SimCity 2000 players?), this interview with Solaren’s CEO has some interesting info:
He also dismissed fears, raised in the past, that the transmission beam could hurt birds or airline passengers who stray into its path. The beam would be too diffuse for that.
“This isn’t a laser death ray,” Boerman said. “With an airplane flying at altitude, the sun is putting about four or five times more energy on the airplane than we would be.”
A no-fly zone would need to be created, but all kinds of power plants have them so that wouldn’t make much difference.
In a different interview, he also addresses the potential environmental impact of space-based solar:
Q: How will this project impact the environment?
A: The construction and operations of Solaren’s SSP plant will have minimal impacts to the environment. The construction of the SSP ground receive station will have no more environmental impact than the construction of a similarly sized terrestrial photovoltaic (PV) solar power plant. Space launch vehicles will place the SSP satellites into their proper orbit. These space launch vehicles primarily use natural fuels (H2, O2) and have an emissions profile similar to a fuel cell. When in operation, the Solaren SSP plant has a zero carbon, mercury or sulfur footprint. In addition, the high efficiency conversion of RF energy to electricity at the SSP Ground Receive Station does not require water for thermal cooling or power generation, unlike other sources of baseload power (nuclear, coal, hydro).
There might be other problems, and maybe costs won’t go down fast enough, but space-based solar is certainly a field to keep an eye on.
By Michael Graham Richard, Ottawa, Canada on 09.03.09