Wastewater Green Hydrogen Batteries and Micro-grids
TRL 3
Status: Postponed, unlikely to continue
What are Wastewater Green Hydrogen Batteries and Micro-grids?
This project is an innovative green hydrogen concept that uses wastewater from the treatment process as a feedstock for electrolysis. By utilising surplus renewable electricity to power electrolysis, we can generate hydrogen in a sustainable way while helping to balance local micro-grids.
We have been actively researching the role of wastewater electrolysis in renewable energy storage, and early external studies show promising results, including successful applications such as the Borkum project.
Literature Review
A literature review, conducted by Prof Anh Phan and Dr Hannah Gibson through the Arrow programme at Newcastle University, confirmed that electrolysis of partially treated wastewater is technically feasible and is already being explored across several industries.
Arrow is part-funded by the Government’s UK Shared Prosperity Fund through Durham County Council and the North of Tyne Combined Authority (now administered by the North East Combined Authority).
While electrolysis of wastewater for green hydrogen shows promise, there are several technical and economic blockers that must be addressed before large-scale adoption is possible.
Key blockers in wastewater electrolysis include:
- Membrane fouling: Proton Exchange Membrane (PEM) systems are highly sensitive to impurities found in wastewater, leading to clogging and reduced lifespan. Alkaline systems suffer less, but still face degradation over time.
- System efficiency: Electrolyzers typically require ultra-pure water to achieve high efficiency. Using treated wastewater introduces additional resistance and energy loss, making hydrogen production less economical.
- Gas purity and treatment: The hydrogen and oxygen released from wastewater electrolysis contain contaminants and need additional purification, which increases system costs and complexity.
Main blockers for hydrogen adoption include:
Overall efficiency losses: Across production, storage, transport, and end-use, hydrogen systems suffer from multiple efficiency penalties, raising the total cost of energy delivered compared to direct electrification or batteries.
Hydrogen embrittlement: Metals and pipeline materials can weaken over time when exposed to hydrogen, raising safety and durability concerns for infrastructure.
Storage challenges: Hydrogen has a very low volumetric energy density. Storing it requires high-pressure tanks, cryogenic liquefaction, or conversion into carriers like ammonia — all of which are costly and energy-intensive.
Pressurisation and end-use: Whether hydrogen is used in transport, industry, or the grid, it often needs to be pressurised or converted into different forms, adding more steps and inefficiency.
Fuel cell and turbine economics: Fuel cells rely on precious metals such as platinum, driving up capital costs. Gas turbine engines require system modifications to run efficiently on hydrogen and face combustion stability issues.