Project Summary

Green Hydrogen is essential to decarbonise the gas network, but with current PEM technologies requiring up to 153,300,000 litres of highly purified waterannually for a 10MW system this poses a significant threat to water reserves, particularly in communities without substantial water mains infrastructure. This means that rural communities are less likely to benefit from hydrogen usage, which will often focus on highly populated areas.
This project targets the issues of high-water demand and difficulty of supplying low carbon energy to isolated communities by developing Next Generation electrolyser systems which can run off wastewater sources such as rain, well or river water, dramatically reducing demand for precious mains water, increasing resilience of green hydrogen production. The NextGen electrolysers can substantially reduce operational water demands since, unlike PEM electrolysers, they do not require purified water from reverse osmosis, providing agility in the production process.
NextGen electrolysers will integrate with fluctuating renewable electricity production alongside using wastewater, adding resilience to hydrogen production and effectively supporting the SIF challenge aims of providing robust, agile and resilient energy systems, whilst accelerating decarbonisation of major energy demands.
The large numbers of different end usage cases experienced by HydroStar pairs with the extensive operational knowledge of WWU as the lead network and NGED as a project partner acting in an advisory capacity to ensure whole system representation, to deliver the project successfully and realise the benefits of the innovation.

• WWU---regulated gas distributor at the forefront of the transition to net-zero, currently managing 412 GWh green-gas across its network. Recognising thecomplexity of the subject, WWU will support through an experienced projectmanager.
• HydroStar---cutting-edge developer of membraneless electrolysers that uniquely run off any wastewater source, creating dramatic water resource savings of up 86%, simultaneously slashing CAPEX.

There are a number of different use cases for the innovation, however, this project will initially analyse high gas demand industrial businesses for proof-of-concept,from which knowledge can be applied throughout the gas network. The needs of the innovation users are common across the board with a resilient, decarbonised and sustainable gas supply required for industrial and domestic users alike.
HydroStar are working with Yeo Valley, Burt's Crisps and Muller on commercial  decarbonisation strategies, along with Exeter-City-Council and Devon-County-Council on public sector strategies (Letters-of-support available on request).

Innovation Justification

At present, electrolysers use extensively purified water, wasting significant amounts of drinking water within the purification process and requiring expensive plant to be co-located onsite. Additionally, electrolysers are only widely operated from constant energy profiles from the grid. These are costly and inflexible processes, consuming vast quantities of water and only achievable at certain locations.
The problem this project aims to solve are current knowledge gaps, primarily effects of different wastewater types on Green-Hydrogen production and the associated efficiency levels, along with electrolyser operation with fluctuating renewable sources.
The two key focus areas are the use of wastewater sources such as rain (harvested), well or river water instead of highly purified to create Green-Hydrogen, and by using low-cost Next-Generation electrolysers matched to renewable generation to produce Hydrogen at below £4/kg.
The novel and innovative approach uses Bio-Ionic electrolytes (green/non-caustic) to enable NextGen electrolysers to use harvested rain, well or river water for electrolysis. Particular emphasis is placed on biological aspects and removal of microplastics. The project will address these gaps by creating a testing rig to test different water types and operation from fluctuating production, exposing thesystem to multiple operating conditions and analysing the response. NextGen electrolysers use disruptive membraneless electrolysis, removing the need for expensive membranes or cryogenic separation. The electrolysers have already been modelled, with calculations verified by the National-Physics-Laboratory in a funded A4I-project. This project aims to discover how real-world operation compares to modelled production.
Economic and environmental sustainability are at the heart of the innovations. The ability to use wastewater can vastly reduce water consumption compared to alternative electrolysers in the market, e.g---PEM, which consumes 7 litres of drinking water to produce 1 litre of Green-Hydrogen feedstock. When scaled to a hydrogen economy, billions of litres could be saved. Economic benefits are reduced resource usage, carbon savings from reduced natural-gas usage (augmented with Hydrogen) and low-cost manufacturing of NextGen electrolysers with Stainless-Steel electrodes rather than Platinum coated Titanium, lowering CAPEX and environmental impacts.
The early TRL of NextGen electrolysers means that high levels of risk are inherent and therefore not considered part of BAU activities as per regular price control mechanisms. Therefore, government funding is required to reduce the associated risk to acceptable levels. Other funding mechanisms e.g---NIA, were considered, but this project is very applicable to the SIF, with the ability to move with agility through the three SIF stages to a demonstrator solution.

Project Benefits

Financial - Cost savings
Green Hydrogen from Next Generation electrolysers facilitates direct financial benefits to network customers. Key issues of energy security and stability of prices have been highlighted within the last year. NextGen electrolysers running off renewable energy can facilitate this, meaning customers do not experience stressful and crippling energy bill increases. Furthermore, reduced CAPEX costs of NextGen electrolysers results in lower prices per unit of hydrogen compared to current sources.
Substantially reduced water demand of NextGen electrolysers, enhanced by the ability to use wastewater, reduces stress on local water systems. This means new infrastructure investment which would pass on costs to customers are avoided.
In this phase, metrics will be modelled instead of measured. The following metrics will be modelled to quantify Green-Hydrogen cost savings;

1. Water usage and source (litres of rainwater, well water, mains water) allowing quantification of water savings.
2. Electricity usage(kWh) tracking renewable energy consumption of electrolyser allowing quantification of reduction in wasted curtailed power.
3. Green Hydrogen production (kilograms) Allowing quantification of carbon savings from natural gas replacement, calculating electrical efficiency of electrolyser
   Tracking of benefits will occur during the physical demonstration and emulation stages, planned to be by the end of Year 2 where Beta Phase infrastructure would be operational.

Environmental - Direct/Indirect CO2
Gas CO2 savings
CO2 savings are calculated per kWh of natural gas replaced. Calculations take into account direct emissions along with indirect Well-to-Tank emissions (WTT---anaverage of all GHG emissions from production, processing and delivery) for natural gas. A Life Cycle Analysis (LCA---methodology for assessing environmental impacts associated with all the stages of a commercial product) providing CO2 footprint of Green-Hydrogen from solar. All calculations use Government-Conversion-Factors.
Natural gas---0.184kgCO2e/kWh
WTT---0.03446kgCO2e/kWh
Total emissions---0.21846kgCO2e/kWh
1kgH2---33.33kWh
Hydrogen emissions from solar--- 1kgCO2e/kg
Therefore---0.03kgCO2e/kWh
REDUCTION = 0.21846 -- 0.03 = 0.18846kgCO2e/kWh (86%)
10MW system at 100% capacity produces 1,460,000kgH2/annum, removing 9,170,803kgCO2e.

Water CO2 savings
Water---0.149kgCO2/m3
NextGen demand -- 15l/kg
PEM demand -- 105l/kg
From above, 10MW system produces 1,460,00kgH2/annum. Resulting waterdemands are;

• 21,900,000 litres from Next Generation (if from mains) = 3,263kgCO2e
• 21,900,000 litres from Next Generation (if not from mains) = 0kgCO2e
• 153,300,000 litres from PEM electrolyser = 22,842kgCO2e

Reductions

• 22,842 -- 3,263 = 19,579 (86% from mains)
• Wastewater---100%

Carbon savings are an important metric, however water demand reduction is potentially even more significant, since the quantity demanded for a hydrogen economy are infeasible to provide through the mains, especially during water shortages.