The increasing proportion of highly volatile feed-in from wind and PV systems requires a decoupling of energy supply and demand. In addition to any kind of storage, technologies such as power-to-gas play a crucial role here. Because the power-to-gas technology combines two elementary goals of the energy revolution: a flexible balance between electricity generation and consumption using the price volatility on the electricity exchange and the appropriate use of the surplus power by converting it to storable methane that is usable in many ways.
How does a power-to-gas plant work? In times when very cheap electricity is available from wind and the sun, an electrolyser converts it into hydrogen. The electrolyser uses this electricity to split water into oxygen and hydrogen, a process called electrolysis. In a second processing step, the hydrogen is then converted to methane; currently, there are various approaches to this conversion step. The methane produced can then be stored and converted into electricity again when required or alternatively used in the mobility and heat sector. The date and location of production of renewable energy are thus decoupled from consumption with respect to time and place.
At the power-to-gas plant in Allendorf, BayWa r.e. is producing gas when the electricity price is low together with Viessmann, a manufacturer of heating, industrial and refrigeration systems. Here, our Trading & Operations Cockpit controls the plant to respond to price fluctuations in the electricity markets and to the demand for balancing power at short notice. The plant’s hydrogen electrolyser gets hydrogen from the current, which is converted into methane by microorganisms with the addition of CO2 from a neighbouring biogas plant.