Power-to-Gas - Investigation of the Overall Energy Network with increasing Regenerative Supply and Analysis of the System Coupling

Project Leader: Professor Dr-Ing Alfons Kather
Duration: 01.12.2016- 30.09.2020

The reduction of greenhouse gas emissions by 80 % until 2050 in comparison to 1990 is one goal postulated by the European Union. Thereby, the share of renewable energies contributing to the electricity mix needs to be increased further. Considering that the goal to reduce greenhouse gas emissions applies nationwide it is not enough to concentrate actions only on emissions from electricity generation. Therefore, this project focusses on interactions between the three main sectors (electricity, heat and mobility) regarding CO2 emissions and the need for energy storage in the future.

Overview of the energy system

At present the share of renewables is quite low in the heat and mobility sector, compared to the electricity sector. To reach the goal of 80 % CO2 reduction, an increased renewables share in these sectors is essential. Through interaction between the three sectors synergy benefits can arise. Solutions like heat pumps or e-mobility are examples of how CO2 emissions can be reduced by combining electricity generation with other sectors.

The present part project here focusses on the impact on the development of the fluctuating renewable power generation from energy storage. Hereby the growing electrical energy demand caused by the electrification of the heat and mobility sectors is considered. Since the power-to-gas technology offers a great potential for long-term storage, the storage in form of gas is investigated. The advantage of storing excess energy in form of gas is conbined with a possible utilization with all three sectors considered (electricity, heat, mobility). In a power-to-gas plant hydrogen is produced through electrolysis using excess energy. The hydrogen can either be stored or optionally be used for a methanation, converting hydrogen to methane. Both possibilities, hydrogen and methane storage, are examined, to highlight their advantages and disadvantages.