Bachelor's thesis Jann Weinand

 

Optimisation and economical comparison of solar thermal- and photovoltaic-system configurations by linear optimisation

Comparison between the costs of a photovoltaic-heat-pump-configuration and a heating system with gas-fired condensing boiler Copyright: EBC Comparison between the costs of a photovoltaic-heat-pump-configuration and a heating system with gas-fired condensing boiler

Solar thermal configurations are mainly used as roof- mounted systems in combination with heating boilers for the production of domestic hot water and room heating. In competition with these systems, roof- mounted photovoltaic systems, that are constantly becoming more affordable, have been offered on the market in combination with electric heat pumps.

In this thesis the total costs occurring over a period of 20 years of solar thermal configurations are being compared with photovoltaik- configurations in a single-family house in Munich. For this purpose, the components of both systems are varied, and the optimal components are worked out with a linear optimization.

As a result the cheaper components outperform the technically efficient components. Although the tecnically efficient components reduce the consumption-linked costs, that result from the purchase of electrical and thermal energy, higher investment costs outreach these benefits. In the solar thermal configuration the unglazed collector in combination with a 500 liter thermal storage device are identified as the most cost efficient components. The photovoltaic configuration achieves minimal total costs in a configuration with cheap photovoltaic panels, a ground source heat pump with surface collector and a thermal storage system with 500 liter capacity. Due to the good ratio between investment costs and technical efficiency, low capacity batteries should be chosen as electric storage devices. Despite lower investment costs, a configuration where the heating boiler is replaced by a heating rod is not favourable. The main reason for this are high consumption-linked costs due to the high demand of electrical energy of this component.

The simulation shows that photovoltaik heat pump combinations have significant advantages regarding electricity and heating costs as well as the total costs.