Intermittency could be solved by storing excess solar as methane

Project VGV aims to store excess solar as methaneAudi is the first company to develop a commercial scale plant converting excess renewable energy generation into methane gas for storage.

Herman Pengg, head of renewable fuels for Audi, joined international nuclear energy attorney Corinne Lepage and University of New York Professor Robert Bell in a Planetworkshops Global Conference discussion about the new Project Volt Gas Volt that the latter two introduced last week in the European Parliament in Brussels.

Project VGV converts excess solar and wind energy generation into methane that can be stored in the natural gas grid and used as heating fuel, to generate electricity or even as a replacement for vehicle fuels.

Audi completed the world’s first industrial-scale installation of the technology this month and will use it as a demonstration of the technology’s viability in the market.

Pengg explained the technology to Automotive Engineer in November.                      

Audi has wind and solar electricity generation capacity. “(The technology) draws electricity whenever there is a surplus, balancing fluctuations in supply,” pengg said.

The first step of the process converts the electricity to hydrogen through electrolysis. The process could stop there. But Audi is interested in developing an alternative fuel that can easily replace gasoline. And since there is no existing infrastructure for hydrogen cars, Pengg said Audi takes the process further. They combine the hydrogen with Carbon Dioxide to produce CH4 – methane. Since methane is the main component in natural gas, it can easily be used to replace gasoline.

“This is what we call Audi e-gas,” Pengg said in November.

He said then that Audi does not intend to become an energy producer. Once the car manufacturer proves the technology, he expects the industry to take over.

Lepage and Bell have spoken about Project VGV in the last weeks as a sound alternative to nuclear power and other traditional electricity sources. This could be the grid storage answer the renewable energy industry has been looking for, they say.

“A breakthrough in energy storage permits a constant flow of electricity,” according to a press release from the pair issued after the EU presentation, “allowing for a shift to 100 percent renewable energy sources, overcoming the major obstacle of intermittent flow of energy.”

If excess renewable energy can be converted to methane and stored in the natural gas grid, it would not only make renewable energy a viable source for all energy needs, Lepage argued. It would also eliminate the need for the controversial hydraulic fracturing process used to extract natural gas.

“With Project VGV, industry and government have the solution for a successful energy transition to optimize wind and solar energy,” Lepage said.