There is a potential market for ‘fuel free’ low CO2 electricity from low temperature waste heat and solar energy. The ‘bottom up’ data collected by ECN from industrial plants in the Netherlands confirm the ‘top down’ statistics which identify large amounts of heat rejected to the environment through final cooling. This heat is easily accessible, and available in locations where large, cold sinks can be built. These sites are often power generating, but additional electricity production could be exported, most likely into the premium ‘green’ power market. A low temperature engine to exploit this market would, eventually, need MW output capacity. CO2 free electricity currently earns a substantial market premium. This is insufficient to provide a commercial return to solar energy in temperate climates, but this market is growing rapidly based on a growing appreciation of solar energy as a clean energy source. To succeed in this market, where costs are now falling, the supercritical approach can take advantage of low cost solar collectors, such as solar ponds, and new heat exchange systems to create low cost (adiabatic) sink capacity at temperatures sufficiently low for efficient operation. Modelling by SAFIRE indicated the possibility of large markets based on decentralized electricity generation as European electricity markets are privatised. The longer-term prospect, however, is for larger (MW), Sun Belt units based on substantial solar capture in ponds, and close coupled with night-temperature ground sinks. Future applications include ocean thermal and low temperature geothermal where the resources are very large.