Here is A Good Approach to the Energy Problem

The Kohkala technology recovers waste heat (or uses solar heat) and produces electricity as well as hot water and space heating from low temperature heat that is usually wasted. This approach will be a boon to homes and small industries that have not been able to utilise cogeneration technologies due to the low level of heat produced. This is one approach to small scale power generation that can be widely applied--especially when combined with newer geothermal technologies. Making use of relatively low temperature energy is like snatching usable energy from the jaws of the monster entropy.

Here is more from Kokhala:

Kokhala's solution uses a unique heat-to-electricity closed loop power cycle solution optimized to generate electricity from external heat sources above 120F. The heart of the EnergyCell® are two proprietary, oil-free variable speed positive displacement expander engines, optimized to efficiently convert the external heat into mechanical rotary power, and then into electricity. The modular components are designed to function in a compound thermal relationship such that a high temperature power cycle is optimized with working fluid circulates between 600F and 250F and a low temperature power cycle is optimized with a different working fluid circulates between 250F and 120F. Since the heat transfer and expansion occurs in a biphase mode, cycle efficiency are optimized and the heat exchangers are minimized. Each expander turns an efficient permanent magnet DC generator with a high turned down ratio. The residual heat from the low power temperature cycle is provide to heat domestic hot water and provide comfort heating for the facility. Based on principles of organic Rankine thermodynamics, the EnergyCell®. exhibit excellent efficiency, low acoustical and electrical noise, no polluting emissions, high reliability and long life.

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