Geothermal Technology
 

Raser uses proprietary heat transfer technology that lowers the flash point to as low as 180° F (82° C)

Raser Technologies holds license rights to several key technologies used in geothermal and other heat transfer based power generation. These technologies include two important and proprietary technologies for more efficient heat transfer and waste heat recovery that have the potential to improve geothermal and other electric power generation efficiencies by up to 30% or more.

Heat Transfer Technology
Raser’s Heat Transfer technology is based on a patented liquid heat carrier that has a substantially lower steam point or “flash point” than water. Water boils at 212° F while the liquid used by Raser is effective at temperatures as low as 180° F. This can be extremely valuable by allowing more low-temperature geothermal sites to be productive. It also allows more economical geothermal sites, using water from shallower depths with lower temperatures, to be productive as well.

Bottom Cycling.
In geothermal sites where much higher temperature water is available, a second stage or “bottom cycling” power generation cycle can be achieved with lower temperatures using this technology.

In addition to using this technology for geothermal power plants, there are many applications where heat transfer with lower temperatures can be achieved as well. In conventional power plants a second power generation cycle can be achieved at lower temperatures using this proprietary heat transfer technology and bottom cycling techniques. This additional cycle can sometimes improve power plant efficiencies by up to 30 percent.

Waste Heat Recovery Technology
Many manufacturing plants and other large facilities often release large amounts of heat in their manufacturing process that is not hot enough for conventional power generation, but can be used to generate electric power using the technologies described above to reclaim waste heat and convert to electric power. Often, enough power can be generated to substantially offset utility fees and expenses.

Combining heat transfer efficiencies with other power plant optimization steps including motors and generators with Symetron™ technology, can yield higher overall plant efficiencies that yield more power generation.

Types of Geothermal Power Plants

Dry Steam.
In dry steam power plants, the steam (and no water) shoots up the wells and is passed through a rock catcher and then directly into the turbine. Dry stream fields are rare.

Flash.
Flash steam power plants use hot water reservoirs. In flash plants, as hot water is released from the pressure of the deep reservoir in a flash tank, some of it flashes to steam. Some problems that arise from Flash plants include complications from natural materials present in the ground water that damage turbines and pipes, and the potential for contamination of the ground water through contact with turbines and other equipment before being reintroduced back into the ground.

Binary.
In a binary cycle power plant (binary means two different liquids), the heat from geothermal water is used to heat and vaporize a second liquid or “working fluid” in separate adjacent pipes through a heat transfer process. The water from the well remains in a closed loop and never comes in direct contact with the surface, air or turbines. It is returned to the well unchanged and uncontaminated. Because of this, binary plants operate with little or no emissions or green house gases. Binary is considered the most environmentally friendly method. Most importantly, binary systems allow a working fluid with a much lower "flash" or vaporization point to be used to generate power from lower temperature and shallower sites. Raser uses a binary method along with a proprietary working fluid capable of a very low flash point. Other advantages of binary systems include no contamination of ground water, and the ability to keep the turbine and other equipment in a closed clean environment.

About Geothermal Power Generation

Fossil fuel consumption has tripled in the last 4 decades and contributed to many environmental problems worldwide. “Energy production and energy consumption cause more environmental damage than any peacetime activity on earth," said Christine Ervin of the Department of Energy.

To combat these problems, the U.S. and other countries are adding “carbon taxes” for energy production. Geothermal energy is proven to be a great energy alternative having the lowest environmental impact, with most consistent power production. Geothermal emits low to no carbon or greenhouse gases (binary is zero). By using electricity from current geothermal plants 22 million tons of CO2 do not enter the atmosphere each year. Likewise, 200,000 tons of nitrogen oxide and 110,000 tons of particulates are also prevented from entering the atmosphere.

As of 1999, 8,217 megawatts of electricity were being produced from some 250 geothermal power plants running day and night in 22 countries around the world; 2,850 megawatts were produced here in the United States. The U.S. is fortunate to have one of the largest concentrations of accessible geothermal sites in the world and energy from these already-identified reservoirs can contribute as much as 10% of the United States energy supply.

Low Temperature Power Generation
Modular Power Generation

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