A lot of wave and tidal power systems being proposed these days will be capable of generating megawatts of power.
Puget Sound Tidal Power is aiming for 10 to 15 kilowatts with its turbine--barely enough for five homes--but the lower power output also means a lower price tag, according to company President Burton Hamner. The total cost of a single turbine from Puget Sound in mass manufacturing will come to around $10,000 or so, he said. The budget on larger turbines often runs into the millions of dollars.
"We think you could get payback in five to eight years," he said during a meeting a the Dow Jones Alternative Energy Innovations Conference taking place in Redwood City, Calif., this week. "We have devised a turbine that is small enough to be mass produced."
Micro power production is a growing theme among energy start-ups. Hawaii's Sopogy is promoting systems for producing electricity from solar thermal energy that would go on a house. Now, solar thermal systems are mostly huge engineering projects taking up hundreds of acres of desert land.
Similarly, Rentricity has come up with a hydroelectric turbine for generating electricity from municipal water plants. Now, hydro power comes from erecting massive dams on rivers.
Puget Sound has essentially created a scaled-down version of a tidal turbine. Overall, the unit stands about 15 feet high. In these systems, ocean tides or current from a river turn a turbine, which in turn generates electricity. Wind turbines do the same thing, but they aren't under water. Water is far denser than air, and tides are more predictable than the wind, so the potential to generate electricity from tides is enormous.
On the other hand, inserting mechanical equipment into the open ocean or a river comes with risks. Thus, most tidal and wave power devices are still in the testing or conceptual stages.
The smaller size has a few advantages, Hamner asserted. For one, Puget Sound's turbine can fit into more places than larger systems. He estimated that there are 500,000 sites worldwide and 10,000 in the U.S. that could be equipped with one of the company's turbines.
The turbines can also be lashed together to mimic the performance of a larger system. The company is currently analyzing the tidal power sites controlled by Tacoma Power, a local utility. One location could be equipped with 175 of the small turbines.
Environmental issues, of course, will have to be analyzed. Putting too many in a river could become a hazard. Puget Sound is also studying which type of turbine blade to use. Ideally, the company wants something that will turn in almost any conditions but also turn slowly enough not to harm fish.
Canada's General Fusion has received $1.2 million in venture funding to conduct further research on its fusion reactors, according to VentureWire.
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, relatively low. (By contrast, roughly $250 million was spent on a 64-megawatt solar thermal plant in Las Vegas recently.)
General Fusion has adopted the 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.
In theory. Conducting those reactions isn't easy. 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.
But research is still ongoing. Los Alamos National Labs is currently conducting research.
Millions have been invested in fusion and nuclear projects over the last decade. Recently, Tri-Alpha Energy, out of the University of California Irvine, landed $40 million in VC funds.
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