Electricity from Photovoltaic Panels or Warm Water from Roof Collectors?
a Department of Energetics, Institute of Chemical Technology, Prague, b Department of Mechanics of Liquids and Energetics, Faculty of Mechanical Engineering, Czech University of Technology, Prague
The article describes various photovoltaic panels and roof solar collectors. Their annual production, capacitance factors, conversion factors, energy efficiency and economical benefits were calculated. Thermal collectors show a higher conversion efficiency and higher heat production but excess heat in summer cannot be usefully consumed. Due to a low temperature of the produced heat the total energetic efficiency of the roof photothermal systems is lower than that of photovoltaic systems. The photovoltaic systems do not need to be supervised, and make it possible to use the electricity at home, at the production site. The excess electricity can be fed into the electric network. New support mechanisms are needed to decrease the investment return time for heat generation in roof collectors.
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