Research into the feasibility of using battolysers to produce green hydrogen

According to the 2021 AR6 IPCC Climate Change report, international greenhouse gas emissions will need to be cut down by 100% by around 2050 to have a chance of staying within the 1.5 degrees C goal set out in the Paris Climate Agreement. Man-made greenhouse gas emissions come from a range of sources including the combustion of fossil fuels, releasing Carbon and Nitrogen Oxides into the atmosphere in the process.

De-carbonising the energy sector requires replacing constant output generators, such as coal-fire and gas powerplants, with intermittent renewable energy sources, such as wind turbines and solar panels, which can introduce unpredictability in generation and a mismatch between supply and demand. This will result in frequency and voltage drops across grids, or over-voltages causing damage to infrastructure, consumer, and industrial devices.
Energy storage is therefore required to compensate for this, drawing power when there is excess generation and providing it when demand is greater than supply for both seasonal and daily management.

Batteries offer rapid response times and will be needed for short-term daily energy storage and management. They have already successfully been implemented at grid and micro-grid scale for frequency & voltage control, and peak power management .

Electrolysers split water into its constituent molecules- hydrogen and oxygen and are seen as a pathway toward decarbonising heavy industry by replacing fossil fuel feed-stocks with hydrogen and its derived fuels. By powering electrolysers with renewable energy, the hydrogen generated can be considered "green hydrogen" and carbon neutral.

Batteries and electrolysers possess similar properties and components. Therefore, integrating the two into a single unit, i.e., a "Battolyser" offers a novel solution to reducing infrastructure requirements and material consumption for both grid-scale and micro-grid energy storage. Battolysers preferably take the form of flow batteries whereby the infrastructure for pumping the electrolyte also functions to move the evolved gases out of the cell.

This research aims to assess the feasibility of a battolyser. To meet that aim, the following objectives have been identified:

1. Understand how a battolyser works
2. Compare different possible chemistries for use as a battolyser
3. Design & build a prototype system of a battolyser and a test rig
4. Test a small prototype system to understand its performance (as a battery and producer of hydrogen). Capacity, hydrogen yields, and discharge profiles of the battolyser will all be measured and the battolyser's equivalent circuit characteristics will be determined
5. Understand the scale up issues