Green Energy News | August 12, 2001

August 12, 2001 – Vol.6 No.20

ENERGIES... week of August 12, 2001

FOUR HUNDRED SUNS. For solar energy to become fully competitive in the energy arena it must be less expensive, more efficient, or both. In laboratory tests Spectrolab has achieved a world-record solar conversion efficiency of 34 percent for its technology known as the triple junction terrestrial concentrator cell.

Triple junction cells are essentially a three-layered photovoltaic (PV) solar cell with each layer, or junction, converting a different portion of the solar spectrum into electricity. In addition to the normal high efficiency of the triple junction cell, the use of sunlight concentrator technology on the cell further increases its efficiency. Spectrolab's triple junction concentrator cells are also capable of withstanding the high thermal energy of concentrated sunlight. The company achieved this record breaking efficiency using light under a concentration of 400 suns.

Using a small number cells together with the appropriate concentrator technology reduces the number of cells needed to generate a given amount of power. The fewer the number cells combined with the high efficiency of those employed lowers the cost per watt of installed solar power.

According to Spectrolab using a concentration of 400 suns along with the cost savings of megawatt scale mass production (enough cells manufactured to generate a megawatt or more of power), this solar technology could be produced for less than $1 per watt. The company also claims that 50 cents per watt can be achieved utilizing higher solar light concentrations.

Spectrolab, which specializes in high-end solar cells for satellites, claims it has the production capacity to manufacture enough of these cells each year to generate hundreds of megawatts of solar power. Arizona Public Service has already placed an order for triple junction terrestrial concentrator cells that could produce 140 kilowatts of solar electricity. Visit Spectrolab at http://www.spectrolab.com/ .

ICELAND TO THE RESCUE. As a world leader in harnessing geothermal energy, Iceland has agreed to share its extensive knowledge with another geothermal hot spot - California. The Iceland Ministry of Industry and Commerce has signed a Memorandum of Understanding with the California Technology, Trade and Commerce Agency (CTTCA) in an effort to expand the state's geothermal resources. The agreement is aimed at helping California eliminate its energy struggle by adding more green geothermal energy to the state's power grid.

Iceland has one of the highest standards of living and some of the cleanest air in the world - in part attributed to its vast clean hydro and geothermal energy resources.

TURBO FUEL CELL. Usually gas turbines, like the jet engine strapped to an airliner, require hot, expanding gases from combustion to operate. Those hot gases, however, don't necessarily have to come from a mixture of exploding hydrocarbon fuel and air. Hot expanding gases can also be derived from another source - the waste heat of a fuel cell.

FuelCell Energy has begun testing a proof-of-concept 250 kilowatt Direct Fuel Cell (tm) modified to work in a hybrid configuration with a 30 kilowatt Capstone Microturbine generator. In the configuration no combustion takes place within the turbine - no fuel is fed into the unit. Hot gases needed to turn the turbine come from waste heat developed by the fuel cell transferred to the turbine through heat exchangers. The addition of the microturbine to put waste heat to work will increase overall efficiency of the fuel cell.

The hybrid fuel cell known as DFC/T (Direct Fuel Cell /Turbine) was developed as part of the Vision 21 Program though the U.S. Department of Energy's National Energy Technology Laboratory (NETL) to develop power plants that could operate near 75 percent efficiency using natural gas while also significantly reducing sulfur and nitrogen oxide emissions. FuelCell Energy will use data from this DFC/T to design a 40 megawatt version as specified by the Vision 21 Program, as well as smaller versions. Testing of this DFC/T will determine if the 75 percent goal can be achieved. Visit FuelCell Energy at http://www.fuelcellenergy.com/ .

LANDFILL GAS TO WORK. The Los Angles Department of Water and Power (LADWP) has fired up the largest microturbine power plant in the world designed to run exclusively on landfill gas. The power plant at the Lopez Canyon Landfill has an array of 50 Capstone 30 kilowatt turbines combined for an output of 1.5 megawatts.

Landfill gas, if not utilized for power generation, is often flared off or allowed to vent into the atmosphere. Landfill gas typically has a high concentration of methane, a more-potent-than-carbon dioxide greenhouse gas. The project is part of the Green Power for a Green LA program. Visit Green LA at http://www.GreenLA.com/