Power-to-Gas Makes Serious Headway

Power-to-gas developments make it a lead contender for storing excess renewable energy.
Published: Wed 12 Feb 2014

Harnessing excess wind power has just become a reality for the German region of Falkenhagen. Wind farms in the area have been producing vast amounts of electricity which the power grid has not been able to handle. But now, with E.ON’s recent power to gas success, that surplus wind power can now be harnessed and utilised effectively.

A power-to-gas unit, installed by E.ON, has successfully carried out the process of injecting hydrogen, converted from excess wind power, into a natural gas pipeline system for the first time. The unit is expected to produce 360 cubic meters of hydrogen per hour when it goes into operation in August this year.

The wind power runs electrolysis equipment that transforms water into hydrogen which is injected into the regional gas transmission system as recently reported on engerati The Dash for Energy Storage Solutions-Renewables Revisited and Germany’s Energiewende is Destabilizing the Grid.

Enormous potential - the numbers

This concept has caught the attention of the power industry as many early pilots have proved to be a success. Natural gas distribution giant Enbridge Inc. has been sufficiently convinced to take a U$5-million equity stake in Hydrogenics in 2012.

Governments around the world are also beginning to realise the importance of finding a solution to energy storage and are throwing their weight behind power-to-gas pilot projects. According to Chuck Szmurlo, vice-president of alternative and emerging technology at Enbridge Inc, the amount of storage capacity in the natural grid is enormous and shows great potential.

For instance, injecting 5% of hydrogen into Ontario’s natural gas grid alone has the potential to generate 2,200,000 MWh of electricity. This would be enough to power 225,000 homes.

Batteries vs. Power to Gas

The industry has been focusing on the battery for energy storage but they have a limited storage capacity and can only last for a set period of time. This is the reason why researchers have been turning their attention towards natural gas as it has vast storage capabilities. Natural gas can be stored in large quantities and then tapped when required. It is using that large amount of storage capacity to hold excess energy produced by renewable that has caught the attention of the power industry.

Excess energy stored in the natural gas grid will be easy to access when there is a need for power. The power can be called up and released into power-generating turbine plants when needed. It can also be used to make fuel for vehicles, or for industrial production, where manufacturing plants can run on clean, “renewable” natural gas.

Gerbert van der Weijde of E.ON points out in his presentation at European Utility Week 2013, Power-to-Gas: A Promising Solution to Integrate Large Quantities of Fluctuating Renewable Power, that power- to-gas is the only service offering long-term and very large scale storage although it can act on short term as well.

What opportunities does the power to gas process offer?

Mr van der Weijde of E.ON explains that the process can integrate renewable power in to different market systems and offers a solution for sustainable mobility. In addition, it is an alternative source for gas with a lower carbon footprint and the gas infrastructure renders large capacities for transport and storage.

Harnessing the ebb and flow of renewable energy has become a major challenge for the power industry. But power-to-gas will overcome these issues as it will become possible to store clean energy in a separate but parallel energy system that already exists. Storage solutions like these will help us deliver flexibility in the power system so that we can tap in to the full potential of renewable energy.

Our Take

It has been our long held view that power to gas is one of the best contenders in the energy storage mix. This is because beyond the numbers stacking up it is also decarbonising heat. Further it causes us to think not just of an electricity grid, gas grid or water grid but an interconnected Energy Grid.