Nuclear Fusion - Coming Soon ?  

CNet's Green Tech Blog has a post on a venture capitalist who believes that commercial power generation using nuclear fusion will be available in the not too distant future. The article says that the process uses lithium - "a fairly inexpensive and plentiful metal" - though that may not remain the case indefinitely if lithium-ion battery production continues to accelerate ("peak lithium" is a concept that has already been broached),

Nuclear fusion will move from the lab to reality in a few years, a noted venture capitalist says.

"Within five years, large companies will start to think about building fusion reactors," Wal van Lierop, CEO of Chrysalix Energy Venture Capital, said in an interview at the Clean Tech Investor Summit taking place here this week. In three to four years, scientists will demonstrate results that show that fusion has a 60 percent chance of success, he said.

If van Lierop were some crazy guy off the street with an old stack of Omni magazines, you could dismiss him. Fusion--which extracts energy from nuclear reactions without the dangers associated with nuclear fission--has been studied for decades, but has yet to go commercial. Van Lierop, however, isn't a random individual. He is one of the earliest and more active investors in clean tech: Chrysalix started investing in clean energy in 2001. The firm's limited partners include BASF, Shell, and Rabobank.

Chrysalix's optimism is pinned on an angel investment the company made in General Fusion, a Canadian company that says it has found a way to hurdle many of the technical problems surrounding fusion. The company's ultimate plan is to build small fusion reactors that can produce around 100 megawatts of power. The plants would cost around $50 million. That could allow the company to generate electricity at about 4 cents per kilowatt hour, making it competitive with conventional electricity.

The company uses a technique called Magnetized Target Fusion (MTF) model. In this scenario, an electric current is generated in a conductive cavity containing lithium and a plasma. The electric current produces a magnetic field and the cavity is collapsed, which results in a massive temperature spike.

The lithium breaks down into helium and tritium. Tritium, an unstable form of hydrogen, is separated and then mixed with deuterium, another form of hydrogen. The two fuse and make helium, a reaction that releases energy that can be harvested. So in short, lithium, a fairly inexpensive and plentiful metal, gets converted to helium in a reaction that generates lots of power and leaves only a harmless gas as a byproduct. MTF has an advantage over other fusion techniques in that the plasma only has to stay at thermonuclear temperatures (150 million degrees Celsius) for a microsecond for a reaction to occur, according to the General Fusion's Web site. General Fusion has also filed for several patents.