France has set itself some ambitious targets for 2030: to increase the renewables contribution to total energy consumption to 40%, and boost the percentage of total gas consumption accounted for by gas from renewable sources to 10% . Power-to-Gas is an innovative technology that converts energy generated from renewable sources into gas to increase the contribution made by green electricity and gas to the French energy mix. We explain why the technique is a crucial part of the energy transition.
Renewable energy sources like solar power and wind power have the potential to generate more electricity than consumers need. If that power is not stored, it is lost and cannot therefore be reused at times of higher demand or when generation from renewables is at a low level on dull days and/or days with little wind.
As energy from renewable sources becomes more abundant, estimates suggest that we could be looking at more than 50 terawatt hours (TWh) of power per year in surplus electricity by 2050 . But since the storage of electricity remains in its infancy today, how can we make use of these surpluses now? The answer is by storing them in the form of hydrogen, a gas with the ability to store large volumes of energy over long periods of time. The use of this energy vector to offset the inherently intermittent nature of renewable energy sources, and therefore match generation to demand, is what we call Power-to-Gas.
It’s a simple process. Surplus electricity from renewable sources is used to power electrolyzers that deconstruct water molecules into their component hydrogen and oxygen molecules. This green hydrogen can then be stored and recovered later as electricity using a fuel cell, or injected directly into the natural gas supply network. It can also be combined with carbon dioxide (CO2) to produce methane syngas.
So Power-to-Gas offers not only the opportunity to reduce the carbon footprint of gas supply networks, but also to encourage the generation of electricity from renewable sources through its ability to recover surplus power.
Construction work on France’s first industrial-scale Power-to-Gas demonstrator - Jupiter 1000 - began on December 18 last year at Fos-sur-Mer on the Mediterranean coast of southern France. The project is slated for commissioning in 2019. Led by GRTgaz, the project is designed to convert surplus electricity generated by wind farms in the surrounding region into green hydrogen and methane syngas. Two electrolyzers will produce the hydrogen, and a methanation reactor will combine the hydrogen with CO2 to create methane syngas, whose properties are identical to those of natural gas. The CO2 used will be extracted from fumes generated by neighboring industrial plants, thereby helping to reduce local pollution. The demonstrator will have a total generating capacity of 1 Megawatt electric (MWe).
In addition to its status as the country’s first megawatt Power-to-Gas plant, Jupiter 1000 is a first in France for a number of other reasons: