Combined heat and power production
Concentrating solar power (CSP) technologies use mirrors to concentrate the Sun's light energy and convert it into heat for production of electricity via a steam turbine or heat engine. Combined heat and power (CHP) systems capture usable heat produced during electricity generation in a single and highly efficient process. Scientists working on the EU-funded project E2PHEST2US investigated a novel conversion module (CM) concept for CSP. The CM employed thermionic and thermoelectric converters connected thermally in series developing advanced materials for thermionic conversion at 700–900 degrees Celsius. This is higher than that typical for CSP but less than that commonly required for thermionic conversion (over 1 300 degrees Celsius). The thermoelectric stage facilitated exploitation of temperatures from 400 degrees Celsius down to room temperature. A heat recovery system was designed to collect waste heat at intermediate temperatures for cogeneration. In addition, a unique hybrid cable was manufactured that is able to carry both high-temperature fluids and electricity. Research results led to the submission of three patent applications. A small-scale prototype solar system highlighted successes in terms of performance of the novel materials and technology, and also pointed the way to areas for continued research and optimisation.