Integration of a LOHC storage into a heat-controlled CHP system

In order to enhance efficiency of thermal energy supply in residential buildings, combined heat and power (short: CHP) systems are more and more replacing conventional heating systems. However, heat controlled CHP systems either generate an excess of electrical energy, which is commonly fed into the power grid, or suffer from a lack of electrical energy, which has to be covered from the grid. In order to increase self-sufficiency and self-consumption, electrical energy storage should be integrated into a heat controlled CHP system. Therefore, an electrical storage based on a Liquid Organic Hydrogen Carrier (LOHC) is investigated in this work. For this purpose a heat-controlled CHP system coupled with an LOHC system is modelled and simulated. The CHP system and the LOHC system were evaluated concerning key figures like self-sufficiency, self-consumption rate and primary energy demand. Moreover, a comparison between an LOHC system and a battery system was done. Both systems showed that with an additional electrical energy storage system the primary energy demand can be significantly decreased and the self-sufficiency and the self-consumption rate can be improved. Best results concerning electrical self-sufficiency could be achieved using a battery. Both systems are able to reduce the primary energy equally, however with the LOHC technology slightly more primary energy can be saved. (C) 2016 Elsevier Ltd. All rights reserved.