Reversible hydride thermal energy storage cell optimized for solar applications

Abstract

A solar energy collection and storage system and a method of collecting and storing solar energy. The system includes a device for focusing solar energy onto a reaction chamber for the conversion of metal hydride to liquid metal and hydrogen, a metal / metal hydride chamber containing a metal / metal hydride mixture, a hydrogen storage system using hydrides and a thermo-cline for recovering the thermal energy from the hydrogen when it is cooled from 2000 F to ambient conditions for storage.

Description

FIELD OF INVENTIONThis invention relates to a solar energy collection and storage system and more particularly to a solar energy collection and storage system which converts solar energy into thermal energy storing the energy in the heat of formation of calcium hydride.BACKGROUNDSolar energy provides a thermal power source which can supply a significant fraction of the world energy needs. A complete system which can absorb the sunlight during the day and produce continuous electricity provides a benefit to the society. Large scale solar power production, in GWatt quantities, is the focus of this patent. A power tower concept provides a solution where a central receiver absorbs sunlight from a field of mirrors focused on the tower. The Barstow facility, Solar 1 and 2, provides an example of this type of facility. For extended operation a thermal storage medium of potassium nitrate / sodium nitrate salts allow several hours of extended run time beyond the daylight hours. These systems u...

AI Technical Summary

Benefits of technology

Providing continuous electricity from solar significantly increases the benefit and usefulness of this energy source. This invention utilizes the heat of formation between calcium and hydrogen to form calcium hydride as the energy storage medium. Calcium hydride provides up to 20 times the energy density of the solar 1 and 2 salt systems.

The hydrogen, separated during the daytime, is stored in a separate low temperature hydride tank which allows a low cost bulk storage technique for the hydrogen. Titanium iron hydride provides a low cost storage solution for the hydrogen.

The advantage of this system is that it is a completely reversible closed cycle. The intermittent sunlight can be chemically stored and released at a controlled rate for electric power production. The system uses materials which are low cost and provide a competitive electrical production facility for both small and very large scale application.

Problems solved by technology

The energy density of the salt mixture requires significant quantities of salts to provide a few extra hours of operation due to the low energy density.

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