| Abstract |
How great can the coverage of Self-generated PV electricity be for the Generation of buildings heat? In order to become more independent of energy suppliers and fossil fuels, more and more people are making use of energy which their own land can provide. Soil and groundwater supply enough thermal energy, even in the deepest winter, to heat a building. Such energy is rendered usable by means of a heat pump. It extracts heat from the soil with the help of electrical energy and “pumps†it up to a higher temperature level. The electrical energy or a portion thereof can also be generated using a photovoltaic installation on one’s own land. Generating solar power on one’s own roof and consuming it in the house, may be more economical today than feeding it into the grid. The more electricity one can use oneself the better. And a heat pump and photovoltaic installation are ideal complements. The photovoltaic installation supplies inexpensive electricity for the heat pump and thus reduces heating costs. In return the heat pump enhances the economic efficiency of the photovoltaic installation by the greater use of solar power. The environment also benefits from this equipment combination since, whereas the heat pump electricity from the power grid is generated partly regeneratively and partly conventionally, the self-generated solar electricity is always 100% regenerative. Seen over a whole year there is always a mix of grid and solar electricity. How great the solar portion is will depend initially on the given quantitative relations; for example, the electricity consumption of the heat pump and the yield of the photovoltaic installation. For a well-insulated single-family house it can be about 30 to 50 %. A further crucial factor is the extent to which the two systems are coupled with one another. By the simplest of methods it is possible today for the heat pump to switch itself on automatically whenever there is a surplus of solar electricity. The paper will give an overview of the subject of combined geothermal source heat pump and photovoltaic installation and is intended to communicate and highlight basic knowledge of the combination of these two technologies. Using a calculation tool, different modes of operation, including storage technologies, can be simulated to ensure that the heat pump can be operated for the most part with self-generated electricity. The presentation will be supplemented by best practice projects which give an overall view of the various possible uses and technologies. Leonhard Thien EnergyAgency.NRW Head of Geothermal Energy Division T: +49 234 32-10715 F: +49 234 32-14070 M: +49 171 7770900 E: thien@energieagentur.nrw P: Lennershofstrasse 140, 44801 Bochum |