Project Summary
Wales and West Utilities are partnering with HydroStar to look at features required from an electrolyser system and the associated electrolyte that ensures resilience of hydrogen supply across the network, giving best value-for-money to WWU and its customers, along with other Gas-Distribution-Network (GDN) customers.
Current electrolysers have focussed on stack efficiency and hydrogen purity without considering real-world manufacturing and operational constraints, and the high costs associated. This project focusses on using less pure water, namely rainwater, storm overflow and industrial process wastewater as feedstock, which reduces operational constraints and costs for customers whilst enabling wide-scale uptake of low carbon hydrogen.
Innovation Justification
INNOVATIONS
This project will improve energy system resilience and robustness by developing novel technologies to lower current operational barriers of Green Hydrogen production, namely water purity requirements, electrical grid constraints and hydrogen compression/transportation. This not only reduces future costs of hydrogen for network customers, but reduces single points of failure within the system and enables a distributed injection approach that can reach rural and urban communities alike. The key innovations are;
NextGeneration membraneless electrolyser which can use wastewater as feedstock instead of highly purified water
Total removal of rare metals within the electrolyser design
Green and non-corrosive electrolyte which can adjust based on specific wastewater feedstocks
Efficient matching of electrolysers to fluctuating renewables
Each innovation address real-world constraints, enabling hydrogen generation which is not limited by requirements for high infrastructure. This means that rural communities can benefit alongside more built-up environments, and reduces risks associated with single points of failure as is experienced in large-scale single location generation.
Discovery phase found that 1 litre of purified water requires 6 litres of tap water for purification alone. This represents 50million litres daily at Government 5GW target levels, posing threats to water availability in locations with constrained water infrastructure or annual shortages. Techno-economic modelling found that a 2MW solar/1MW electrolyser system consumed 91% of generated renewable electricity, and 99.5% from a 1MW turbine/1MW electrolyser setup. These systems produce an estimated 37,324 and 82,497kg of hydrogen respectively, reducing an estimated 205 and 454 tonnes CO2 when replacing natural-gas.
Alpha focusses on experimental development of the innovative membraneless electrolyser and green noncorrosive electrolyte, enabling wastewater feedstock and matching to fluctuating renewables. This builds on Discovery feasibility studies, which confirmed technological viability whilst quantifying the benefits of removing water purification entirely.
A counterfactual approach focussed on electrolysers with scope to operate efficiently off unpurified mains water but not wastewater. This addresses purification issues but greatly reduces production ability at locations without mains infrastructure, and does not reduce future demands on this infrastructure.
STAKEHOLDER MANAGEMENT
South-West-Water have been engaged from a wastewater perspective, with process wastewater identified as a potential further innovation, along with NGED for potential electrical demands at different regional sites and electricity network capacities available. A very strong relationship is held with Exeter-City-Council, with discussions on hydrogen production on city industrial estates underway. Further GDNs (Northern-Gas-Networks/National-Gas-Transmission) have been engaged regarding key similarities/collaboration potential in future projects, with both networks supportive of project focusses.
High gas demand customers, some with process wastewater, have been engaged about hydrogen offtakes (see-Section-10), with the potential to investigate colocation strategies which use onsite wastewater to produce hydrogen, then consuming hydrogen/byproduct oxygen onsite.
As a 6-month timescale with electrolyser/electrolyte experimental development, the project scale supports SIF objectives, providing vital insights into wastewater usage required to develop large-scale systems in Beta phase and during mass infrastructure development. Alpha uses insights gained during Discovery to guide key tasks and greatly increase TRL.
READINESS LEVELS
Commercial
Current---5/6. Expected---6/7. Financial models will be validated, with focusses on exploitation through customer integration and agreements, and innovation protection through patenting
Technology
Current---4/5. Expected---6. Technology validation/demonstration will be achieved during tests with electrolyte/electrolyser, and output analyses
Integration
Current---3. Expected---4/5. Experimental development of electrolysers/electrolyte will enable termination/management methods between the two technologies based on changing inputs
FUNDING
The project cannot be funded elsewhere or considered as business-as-usual because of the early-stage nature of the innovation. HydroStar has considered private equity investment, with Hydrogen One and Investec expressing interest in funding innovative hydrogen projects, however early-stage innovation risks are outside their investment scope. HydroStar will be considered within investment scope once the technology has been demonstrated at scale.
Impacts and Benefits
Impacts and benefits descriptionThe Environmental and Financial benefits realised during Discovery Phase are quantified below. The New-to-Market benefits have been expanded during Discovery to refine their focusses.
Environmental---carbon reduction---direct CO2 savings per-annum
Natural gas produces 0.18254kgCO2/kWh of gas consumed, and 0.0311kgCO2/kWh as Well-to-Tank emissions (Government-Conversion-Factors). This equals a total of 0.21364kgCO2/kWh for the current position.
Lifecycle analyses of Green Hydrogen indicate a carbon footprint of 1.7kgCO2/kg (Royal-Society-of-Chemistry). The calorific value of hydrogen is 33.33kWh/kg, therefore the assumed carbon footprint of Green Hydrogen is 0.051kgCO2/kWh, with this value to fall further as the supply chain develops.
This represents a 76% reduction compared to natural gas.
WWU distributes 60.5TWh of natural gas annually, equivalent to 1,815Mt of hydrogen and with a carbon footprint of 3,086MtCO2. Therefore, annual direct carbon savings of 2,345MtCO2 are possible by using Green Hydrogen over natural gas as BAU.
Environmental---carbon reduction---indirect CO2 savings per-annum
Discovery phase calculations have shown significant carbon emissions associated with water purification to reach the required standard of ultrapure water that current electrolysis technology requires.
Purification processes require 6 litres of tap water to create 1 litre of highly purified water, or 6,000litres/m3, with electricity consumption of 3kWh/m3. UK tap water has a carbon footprint of 0.149kgCO2/m3 and 2022 UK electricity a footprint of 0.19338kgCO2/kWh. Therefore total carbon emissions of delivering the current position of highly purified water for electrolysis is 1.47414kgCO2/m3.
Direct water consumption of electrolysers is 10l/kgH2. To deliver the equivalent 1,815Mt of hydrogen which would be distributed by WWU annually, 18.15million m3 of water is required for purification alone. This represents a carbon footprint of 26,755,641kgCO2 which could be saved indirectly from using water which does not require a purification process.
Financial---cost savings per-annum on energy bills for consumers
Techno economic modelling within Discovery phase found that the LCOH (Lifetime-cost-of-hydrogen) from a 2MW solar/1MW electrolyser system using wastewater sources as feedstock instead of highly purified water was 19% cheaper, at £5.98 instead of £7.41 at an electricity cost of £80/MWh. A similar reduction was found from removing the need for compression through distributed injection into the network, reducing costs from £7.12 to £5.97.
Further modelling investigated wind energy for hydrogen generation, showing a 1MW turbine/1MW electrolyser could generate at a LCOH of £2.13 if all plant/generation were owned, representing a significant reduction in price compared to the current Green Hydrogen prices of between £7 and £10/kg.
New to market---Products
Electrolysers which can operate from wastewater feedstock without the need for highly purified water, using membraneless technology to also reduce the capital costs of electrolysis systems.
An electrolyte which facilitates the process and can handle the different ions present in wastewater sources without limiting the electrolysis process or creating dangerous byproducts, and can be changed slightly to account for changing ion concentrations
New to market---Processes
Production of Green Hydrogen from wastewater or less pure water, helping to achieve the 2030 Government 5GW electrolysis targets by lowering operational barriers and site requirements for electrolysis production.
This enables a distributed generation strategy, injecting hydrogen at strategically beneficial network locations to enable operators to control/track hydrogen more easily, delivering specific concentrations to locations dependant on user requirements. Capital/operational costs are reduced, with distributed injection reducing the need for compression or transportation, which currently has high energy/financial costs associated.
New to market---Services
Colocation services for water treatment and onsite gas demand production, reducing overall energy/fiscal costs and with potential to supply oxygen demands for any onsite processes as an electrolyser byproduct
Nodal hydrogen injection services into specific locations on gas networks to increase hydrogen quantities or concentrations required at these locations, improving security-of-supply for both network users and operators
