Planning, Optimisation and Evaluation of Small PtGtP Systems: Case Study of a German Dairy

In the course of the energy transition, distributed, hybrid energy supply concepts, such as the combination of photovoltaic and battery storages, are increasingly being used for economic and ecological reasons. However, electricity generation is highly weather-dependent and the storage capacity of batteries is limited. Nowadays, a new component is emerging for distributed energy supply: the Power-to-Gas-to-Power (PtGtP) technology which stores electricity as hydrogen even over longer periods of time. As this is still a relatively new application, there is still a lack of valid assessments of its usefulness and prospects. In order to be able to give such an assessment under the current German market conditions, a methodology is being developed that optimises the sizing and operation of such a PtGtP as part of a hybrid energy system. The evaluation is based on a multi-criteria approach optimising for both costs and CO2 emissions. In order to gain further insights into this energy supply concept and its future prospects, a sensitivity analysis is carried out, where key parameters are identified and their effects on the results are described. The methodology is used to examine the case study of a dairy and shows that PtGtP is not yet profitable but promising.