Power-to-gas system enables massive storage of renewable energy

Power-to-gas (P2G) is bringing fresh momentum to the renewables field, providing a powerful approach to convert renewable power into ‘green’ hydrogen and methane. 

An EU-funded project developed flexible P2G technology that offers the renewables sector an array of possible lucrative use cases.

Currently, the renewable generation capacity is estimated at around 20 %, but according to the International Energy Agency, it is forecast to increase by 50 % between 2019 and 2024. Certain countries already have plans to transition their electricity supply resources to 100 % renewables by 2050.

These renewable energy scenarios bring many benefits, but also face significant challenges. Wind and solar power are highly intermittent – their electrical output cannot be used at any given time to meet society’s fluctuating electricity demands.

Power to gas: a critical ingredient in the energy transition

P2G technology is one of the few viable options for large-scale energy storage solutions. Converting excess renewable energy into methane allows storing high energy amounts for a long time in existing gas infrastructures. Researchers working on the ProGeo project successfully developed a 500-kW power-to-gas modular unit.

The system can store electricity by converting ‘clean’ hydrogen and CO2 into methane with high flexibility. Methane is a flexible energy carrier that once purified can be used in manifold ways.

Results from demonstration activities showed that the newly developed system can produce 25 Nm3 of gas per hour, achieving 99 % pure methane out of CO2.

Benefits of P2G

The ProGeo solution can highly benefit small thermoelectric power and cogeneration plants. The P2G system can be used to store the energy, in the form of methane, and when needed, be converted into electricity or heat. “Thermoelectric power plant owners will have a chance to choose whether to sell or store the produced energy, avoiding the sale of low-priced electricity during low-peak hours,” explains Torrisi. What’s more, the ProGeo system can increase the sustainability of the P2G conversion process.

The ProGeo solution is one of the most efficient, cost-competitive alternatives to a low-carbon economy, helping maintain electricity grid balance.

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