Photovoltaics or Solar Thermal –The Winner Takes it All?
Abstract
The future will see a further growth of PV. This depends from many factors but the worldwide trend for PV is still a growing market. In industrialized countries with heating systems and air conditioning the PV will push ST out of the main markets outside the niches described above. There are several markets for solar thermal. One is for very cheap compact solar hot water systems in the sunbelt-regions. As many regions will not have a grid, PV is more concentrated on small solar home systems (SHS) and micro grids. On the other hand in cold alpine climates with high sunshine, solar thermal is still interesting. Solar air systems could find their place in such systems. In the range of big system the district heating is a market for solar thermal systems too. Switzerland actually needs about 60TWh for electricity which are produced mainly by hydro- and nuclear-power. PV contributes to about 3% of the market. In the “Energy Strategy 2050” of the Swiss government the five nuclear power plants will be shut down in future. The replacement is mainly PV, Wind, geothermal and other renewable sources as small hydro, waste combustion etc. PV should bring about 12 TWh (1,5 kWp or 8-12 m2 per person). Conside¬ring the low possibility for geothermal, the problems with the construction of windpower in Switzerland and new consumers as EV I see up to 24 GWp as possible (3kWp or 15-20m2 per person). Swiss utilities still own more than 6TWh windenergy outside Switzerland. This is helpful to produce electricity in the winter. The Swiss PV market should grow from 300MWp to 600-1’000MWp annually to fulfill the targets of the “Energy Strategy 2050” and to cover the needs of 5 million electric vehicles. The worldwide PV market could grow from 100 GWp to 1’000GWp and more. The solar thermal market will still be under pressure as the demand for heating is going down. Clever marketing strategies for 100% multi-level houses could occupy a market niche. Small hot water systems will be replaced more and more by PV and heat pumps. Unfortunately the market of district heating was never tackled in Swit-zerland. In the big picture PV will be the dominant technology in the active solar applications. Here it’s the winner which takes it all!