Hybrid Photovoltaic Solar-Thermal Collector Does Both Jobs

The Turkish company, Solimpeks Corp., has launched its Volther hybrid photovoltaic-solar thermal collector, which produces electricity and hot water simultaneously. The hybrid system allows extra module heat to be absorbed to produce hot water while optimising efficiency, the company says.

Historically, the main drawback of many conventional photovoltaic (PV) systems has been the high initial cost and limited amount of electrical output compared to the solar input. This new system allows excess heat to be recaptured and boosts the system’s return on investment (ROI), announces Solimpeks.

Any PV cell is negatively affected by heat, with output dropping by around 0.5 % for every Kelvin degree. A 10-degree rising in temperature, for example, would mean a loss in power output of about 5%. Scientists at Solimpeks have turned this problem into a solution by developing its “PV-T”: a hybrid PV and solar thermal collector, which enables the PV cells to be cooled using water circulating around them. The result, greater electrical output from the cells and the production of hot water.

As well as increasing PV module performance, the PV-T hybrid collectors mean that less roof space is required for the same output of electricity and hot water, since only one system is needed as opposed to a solar thermal array and PV array side-by-side. Furthermore, Solimpeks reports that the hybrid PV-T system’s ROI is shorter than the PV systems, and because PV cell temperature is reduced, the lifetime of cells is lengthened.

According to the Turkish company, calculations by several scientific organisation and universities show that an average family house in northern Europe would require only 25 square-metres of PV-T collectors to meet its hot water and electricity demands.

Solimpeks’ R&D Manager, Joop Hoek, also explains that excess electricity from the system could be stored in normal batteries or hydrogen fuel cells, while heat could be stored underground; giving the example of the Drake Lake solar project, where 52 homes were heated through the winter by Solimpeks using solar thermal energy collected during the summer.

www.solimpeks.com

New Report Says The Major Solar Thermal Market Is China

The report “Solar Thermal Power Report” describes solar thermal energy technology in its various applications. Although concentred solar power (CSP) generation is probably better known, solar thermal (ST) collectors employ a much lower level of technology and convert far more of the sun’s energy into useful heat. Perhaps least well known and in its infancy, but a technology of the future, is ST cooling. The report describes the various technologies: collectors, receivers, heat storage systems and energy conversion units.

ST collectors have more capacity and produce more energy than wind power and more than geothermal, solar PV and ocean energy combined. By 2009 there were147,000 MW of wind power, 174,000 MW of solar thermal collectors for water heating and building heating or cooling installed, but only about 1,000 MW of high temperature solar thermal collector generating capacity and about 17,000 MW of solar PV capacity.

According to the 75 page report, the major solar thermal market is China, which leads the world by a long margin, followed by the United States, Germany and Turkey. Although the installed capacity of CSP, solar power generation is still small it has started to take off in the last two years, notably in Spain and the United States.

Report Scope
Electricity cannot be stored in any large measure, but heat can. Because solar thermal energy, like wind, is intermittent, the storage of heat is crucial to its success. Energy captured during sunny periods of low demand can be stored for use in periods of high demand.

The last two or three years have seen strides forward in all solar technologies and many 50 to 100 MW CSP power generation projects are being developed, with larger ones in the pipeline. The major direct use solar thermal markets – China, USA, Turkey, Germany and Japan are outlined and current market sizes provided. Israel is important for per capita use but relatively small in total. Between them, they have 75% of the global market for solar thermal collectors and ancillary equipment. The growing CSP markets of Spain and the United States are outlined, with lists of projects already competed, under construction and planned.

www.reportbuyer.com