Solar power and solar hot water are usually two separate systems, but some companies are looking at combining the two to make more effective use of the sun.
When the sun’s rays hit a solar panel, aside from electricity, heat is generated – and is usually wasted. An overheated solar panel also loses some of its efficiency.
To get around this issue, systems are being developed that have water pipes attached to the back of solar panel. The heated water is then pumped into a tank ready for use, cooling the panel in the process and allowing it to work more effectively.
Other companies are looking at a different method; using an extension of a solar hot water system concept to also create electricity.
Cool energy is developing the SolarFlow System, which generates solar electricity when heat from the solar thermal collectors is not needed in the host buildings. During the winter, most of the energy from the collectors is used to heat the building’s living space and services hot water requirements. In the summertime, the system’s engine converts that thermal energy to electricity via a Stirling engine.
A Stirling engine converts heat energy into mechanical power, which can be utilised for spinning a turbine, by alternately compressing and expanding a fixed quantity of air or other gas.
Cool Energy is currently building its third-generation engine prototype for a pilot SolarFlow installation planned for the summer of 2009 at a public facility in Boulder, Colorado.
Related:
Solar hydronics – thermal energy for home water and space heating
