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Sunday, September 4, 2011

Energy Information Available to Australian Politicians

GE Hybrid Power Station
The information on the Australian Parliament Library webpage "Clean Coal" is no longer current.

A summary of more recent technology is available in a submission "Australia's Clean Energy Legislative Package" and in a short article "power station operator gets great value for investors".
These technology changes that are not mentioned at present include:
  • Coal can be gasified to produce Natural Gas (Substitute Natural Gas, or "SNG"), and used either in power stations or any other application where natural gas is used. eg. Compressed Natural Gas (CNG) to fuel cars, trucks and buses.
  • In Coal to Natural Gas conversion, 50% of the carbon is separated as carbon dioxide.
  • When the resulting Natural Gas is used in a power station, thermal efficiency of 60% can be achieved. This compares to 35-40% when the coal is burned in a coal-fired power station.
  • The effect is to reduce carbon dioxide emissions by 65% - 70% from about 1,000 kg per megawatt-hour to about 330 kg per megawatt-hour.
  • A further benefit is that the same electrical energy can be produced with about 2/3 of the coal when the coal is burned in a coal-fired power station.
The Parliamentary Library webpage states "An example is gasification of coal by burning it in oxygen".
Coal gasification can also be carried out with concentrated solar thermal energy. In this process, the solar energy contributes about 25% of the final energy generated by the Combined Cycle Gas Turbine (CCGT) power station that uses the resulting Natural Gas fuel. Carbon dioxide emissions are further reduced, and even less coal is needed for the same electrical energy output.
References to some related technology and its use in China, the US and elsewhere include:
The web site also has a completely separate page on "Renewable Energies", and there is no discussion on hybrid fossil fuel/renewable energy approaches.
Hybrid energy systems with coal, gas, biomass and solar thermal energy are increasingly seen as a cost-effective way to add renewable energies into electricity supply grids. Recent large-scale projects are bypassing the limitations and costs of concentrated solar thermal storage:

The Spanish solar research centre co-authored this paper:

Novel integration options of concentrating solar thermal technology with fossil-fuelled and CO2 capture processes
April 1, 2011
Guillermo Ordorica-Garcia a, Alfonso Vidal Delgado b and Aranzazu Fernandez Garcia b

a Alberta Innovates–Technology Futures (AITF), 250 Karl Clark Rd., Edmonton, Alberta, T6N 1E4, Canada
b Plataforma Solar de Almeria (PSA)–CIEMAT, Ctra. Senés Km. 4, P.O. Box 44, Tabernas, Almería, 04200, Spain

"One key shortcoming of Concentrating Solar Thermal (CST) technology is its sensitivity to disruptions in sunlight availability over time. CST systems require either thermal energy storage or backup systems to operate during heavy cloud periods or at night. On the other hand, fossil-based energy systems have high availability and reliability, but they generate substantial CO2 emissions compared to equivalent CST processes.

A novel solution would combine the benefits of CST technology and of fossil-fueled energy systems. Such a solar-fossil hybrid system would guarantee energy availability in the absence of sunlight or stored solar energy."

Two recent projects using this approach:

June 10, 2011
A new hybrid power plant in Turkey will combine a traditional gas-fired steam turbine with solar thermal power and wind power, according to GE. It’s a step toward integrating renewable sources into the traditional power grid, using steam and mirrors. ...the real gain may be in the ease with which wind and solar are being added to the power grid.

Aug 11, 2011
California regulators approve hybrid power plant
The California Energy Commission today approved the construction of a proposed 570-megawatt hybrid power plant in Los Angeles County.

“The project will provide reliable and consistent power,” said Commissioner Karen Douglas, who is the presiding member for the committee reviewing the Palmdale project.

The proposed project consists of natural gas-fired, combined-cycle generating equipment integrated with solar thermal generating equipment. During daylight hours when the parabolic solar thermal collectors are in use, the solar field will provide about 10 percent of the peak power generated.

The solar field will provide heat directly to the heat-recovery steam generators to produce steam, reducing the natural gas used at the facility