BLOG-H (using a Battolyser to produce LOw cost Green Hydrogen)

Earlier this year, the UK government in keeping with many other nations laid out its hydrogen strategy plan. This equates to a target of 5GW of low carbon hydrogen production by 2030. Presently, the most common production route for hydrogen is steam methane reformation. Hydrogen can also be produced through electrolysis of which there are four main types; alkaline, PEM, Anion exchange membranes and solid oxide. The Anion exchange membrane is currently <5000 hours life span and the solid oxide electrolyser has a stack capital cost that exceeds £1500/kWe. The alkaline electrolyser is cheaper at a stack cost of £200/kWe and the PEM is close to £300/kWe. The total cost including balance of plant is closer to £700-£1000/kWe including rectifiers, H2 purification, water supply and purification and cooling. Most units are manufactured at around 1MW, however, there are plans for a 20MW trial unit.

The government has also pledged to move to 100% renewable energy and therefore to meet the technical requirements around electricity grid stability including meeting winter peak at times of low wind, additional capacity renewable generation needs to be installed. Instead of curtailing a wind farm due to grid based operational constraints, the energy produced as part of this can be used to produce hydrogen at minimal extra operating cost. The cost of the hydrogen therefore depends on the capital costs of the technology, storage and transport. If there is ample free electricity, for which there is little other use, then the efficiency of the hydrogen producing is less of an issue than its cost.

This proposal looks at using an alternative and complimentary technology to electrolysers to achieve this; the battolyser. A battolyser is a battery/electrolyser combined and is based on aqueous flow battery technology. Because it is pre-designed for battery functionality too, the electrodes may be more stable than those in an electrolyser. Flow batteries are being designed in scales of up to 100MW, 500MWh compared to Electrolysers at a planned 20MW and therefore there is good potential to scale up battolyser technology quickly once it passes early stage TRL hurdles. Additional advantages of a battolyser include the use of low hazard chemicals and the higher availability of materials used in manufacture. There is also additional potential to link into existing recycling facilities helping with long term sustainability planning.

As the battolyser is a single device which can produce both electricity and hydrogen it has the potential to be more economically viable than an electrolyser because of the multiple value streams.
This project will research the potential of a battolyser to produce low cost green hydrogen. The project aims to show that this is both financially viable and technically possible by modelling, prototyping and characterising a green hydrogen producing battolyser in conjunction with an offshore wind farm. The team based at the Centre for Renewable Energy Systems Technologies (CREST) at Loughborough University will be joined by wind farm experts from Strathclyde University and partner companies FibreTech, Arenko and SSE to complete this research into zero emission hydrogen.