Power plants – Utilizing natural heat – Geothermal
Reexamination Certificate
1998-04-09
2001-06-19
Nguyen, Hoang (Department: 3748)
Power plants
Utilizing natural heat
Geothermal
C060S651000, C060S671000
Reexamination Certificate
active
06247312
ABSTRACT:
TECHNICAL FIELD
This invention relates to methods for using a geothermal power.
BACKGROUND OF THE INVENTION
In many parts of the world, isolated land masses exist which require the importation of fossil fuels to generate electrical power. The Hawaiian Islands are an example of such land masses; and power generation is presently limited to conventional fossil-fueled plants using steam or gas turbines which produce undesirable atmospheric pollutants. In an effort to improve the environment, it has been proposed to utilize geothermal sources to produce power. If the geothermal sources are present on certain outlying islands, the power produced can be sent to the main islands, for example, by conventional underwater power transmission lines. Because the normal electrical load in the islands is such that the load during the day or periods of peak power demand greatly exceeds the load at night, or during periods of off-peak power demand, geothermal power plants inherently are not totally suitable. The problem is that a geothermal power plant usually operates at rated capacity all the time, both day and night. Thus, a plant capable of supplying the daytime load would have excess capacity at night. Because of the geographical isolation of the plant, it is not practical to transmit the excess power produced at night to another customer; and for this reason, large scale geothermal power plants are often not appropriate for the conditions described above. Consequently, conventional fossil-fueled power plants are supplemented by fast starting gas turbine power units for daytime peaking because these units can be brought on and off line quickly. Generating electricity using conventional oil-fired plants using steam turbines for base line power production supplemented by gas turbine peaking is both expensive and polluting.
Geothermal power plants are cost effective, but the nature of these plants is not conducive to quickly starting and stopping, which means that the substitution of such plants for conventional fossil-fueled plants is not practical in a geographically isolated location where excess power at night cannot be disposed of. One approach to this problem is to vent the geothermal production wells at night, and reduce the operating level of the plant to accommodate the low level load during the night. This approach is not desirable because geothermal vapors contain noxious gases which, when released to the atmosphere, are dangerous to human health. Treatment systems exist for removing noxious gases, but the cost of this equipment is prohibitive. It is therefore an object of the present invention to utilize a geothermal power plant in a new and different way so as to avoid the problems with the prior art as outlined above.
BRIEF DESCRIPTION OF THE INVENTION
The present invention provides a method for operating a transportation system based on electric powered vehicles, such as battery powered vehicles particularly suitable for use in an isolated geographic area within which the base electrical load during the day, or periods of peak demand, exceeds the normal electrical load during the night, or periods of off-peak power demand. The method includes the steps of generating power for the electrical load wherein a power production system or a geothermal power plant that operates day and night, preferably at substantially constant power output, may be used or included in the power production system. Thus, for example, during the day, the power plant supplies the required electrical load, and the battery powered vehicles are operated without imposing any load on the power plant. This is particularly effective when the geographical area served by the power plant is isolated, and vehicular traffic is essentially tourist travel.
During the night, the batteries of the vehicles are charged utilizing the power generated by the power plant at night in excess of the normal electrical load. Thus, the electrical load supplied, for example, by the geothermal power plant during the day is the usual daytime load, and the electrical load supplied by the geothermal power plant during the night is the normal nighttime load plus the load imposed by recharging the batteries in the vehicles.
Preferably, recharging stations are provided in the geographic area are linked by roads over which the battery powered vehicles travel. Advantageously, the distance between adjacent stations can be selected so as to be substantially equal to the cruising range of a vehicle which means that a vehicle can travel from one station to the next station on a full battery charge. Such travel occurs during the day so that, at night, the vehicle may be recharged at a charging station.
The invention also consists of a transportation system for an isolated geographic area comprising a ring-road defining the geographical area, and a plurality of re-charging stations spaced around the ring-road. An electrical distribution system is provided for supplying power to the recharging stations wherein the electrical distribution system may include a geothermal power plant that preferably produces power at a substantially constant rate.
Thus, the increased electric load during periods of off-peak power demand, such as during the night, will lead to increased use of geothermal power plants, usually increasing the level of power production of such plants thereby reducing the amount of pollutants produced in electric power production. Also, the use of battery operated cars will bring about a reduction in air pollution because the number of fossil fueled cars or vehicles will be reduced.
REFERENCES:
patent: 1165784 (1915-12-01), Klingelsmith
patent: 4388618 (1983-06-01), Finger
patent: 4542625 (1985-09-01), Bronicki
patent: 4578953 (1986-04-01), Krieger et al.
patent: 4700543 (1987-10-01), Krieger et al.
patent: 4883823 (1989-11-01), Perry, Jr. et al.
patent: 5497624 (1996-03-01), Amir et al.
patent: 5531073 (1996-07-01), Bronicki et al.
patent: 5740672 (1998-04-01), Bronicki
patent: 5857338 (1999-01-01), Rigal
Wiliam Hamilton, Electric Automobiles, General Research Corporation, pp. 163-251, Dec. 29, 1980.
Meyer Jerald L.
Nath Gary M.
Nath & Associates PLLC
Nguyen Hoang
Ormat Industries Ltd.
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