Today's Date: Sunday, September 07, 2008
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EmailPower Generation: Continued
November 30, 2007Page 5 of 15
- Experimental Power - Early stage and experimental technologies are at the farthest edges of green technology. Primary examples of experimental green-power generation use nanotechnology to generate constant power for miniature devices or to provide less resistance for electricity pathways in green-technology devices.
- Microgenerators - Microgenerators harness mechanical energy from ambient vibrations and ultrasonic waves to vibrate arrays on nanowires across a saw-shaped electrode. A number of different prototypes currently exist, in sizes appropriate for devices ranging powering nanorobots to larger industrial sensors. A potential application for microgenerators is powering internal medical devices such as pacemakers.
- Nano Solar - Light is present even at the smallest scales and new research is being done to take advantage of that. Coaxial silicon nanowires concentrically align different grades of silicon into a wire which acts as an electron harvester and proton-transfer unit. Coaxial nanowires are able to self-power nanowire-based logic circuits. Nanoparticle solar cells operate in a similar way. They transmit light through a series of carbon nanotubes, which pass electrons through electrodes to generate electricity. Another technology suspends silicon nanocrystals in a solvent to create silicon nanocrystalline ink, which can be poured on virtually any surface. While achieving efficiencies similar to polysilicon cells, nanocrystalline ink costs about 50 percent less to produce.
Microgenerators PMG Perpetuum Steorn Nano Solar InnovaLight, Inc. >Eikos, Inc. >Suniva - Clean Coal - Fossil fuels will continue to be part of our energy mix for a number of years. While we wait out the death of coal, which some analysts predict will occur in the next 50 to 60 years, technologies developed and deployed today aim to reduce the impact that coal has on our environment. Clean coal technologies reduce the CO2, NOX, SOX, and CO content of coal plant effluent, capture and sequester these pollutants and convert coal into carbon-neutral liquid fuels for electricity generation. The U.S. government has sunk a considerable amount of money into the FutureGen project - the coal power plant of the future. FutureGen is a zero-emissions coal plant that combines coal-to-hydrogen conversion with carbon capture and storage. Waiting for FutureGen, which has a planned deployment in 2012 but currently lacks a final site, seems like a losing bet.
- Internal Gasification Combined-Cycle (IGCC) - A process of high-temperature coal gasification that creates syngas from the carbon monoxide and hydrogen end product. The syngas is combusted and used to power a turbine generator. The remaining heat and steam are also used to spin turbine generators. IGCC enhances the efficiency of coal-powered electricity generation while reducing emissions. Retrofitting coal plants for IGCC operation is cost-prohibitive, while new construction costs come out to roughly $3600 per kW (20 percent more than a typical coal power plant), when construction and operation costs are added in. However, IGCC plants are able to capture CO2 during gasification, significantly decreasing pollution levels.
- Oxy Fuel- This new technology uses oxygen-enriched gas to fire coal power plants. The oxy-fuel process yields an effluent stream that is nearly pure oxygen, and leads to a 75 percent reduction in the amount of flue gas. Oxy-fuel combustion for electricity generation is less efficient compared to IGCC, but its end-product effluent captures and stores CO2 more effectively. Oxygen production is currently the most expensive component of oxy-fuel combustion.
| Internal Gasification Combined-Cycle (IGCC) | ||
| Altarock Energy | Xcel Energy | GreatPoint Energy |
| Oxy Fuel |
| Clean Energy Systems, Inc. |