42T worked with RheEnergise to scale production of its proprietary high-density fluid and deliver the manufacturing system required to commission the company’s first-of-its-kind 500 kW Technology Readiness Level 7 (TRL 7) demonstrator plant.
Key outcomes
The fluid-production capability provided consistent, high-quality batches for transfer into the main storage reservoir, supporting the commissioning of RheEnergise’s first 500 kW TRL 7 demonstrator.
42T translated a laboratory manufacturing method into an operational process capable of producing 5 tonnes of fluid per day. This provided the production capacity required to support the wider demonstrator programme.
The control system automated key stages of the mixing and production process, supporting consistent quality, process safety and repeatability. An intuitive operator interface allowed the system to be operated reliably by non-specialist personnel.
A risk-based engineering approach helped identify and address the most significant scale-up challenges early. This supported delivery of the fluid-production capability from initial concept through to commissioning within eight months.
The challenge
RheEnergise has developed a new form of long-duration energy storage (LDES) that uses a high-density working fluid to deliver the benefits of pumped hydro with significantly lower elevation requirements. This removes many of the geographical constraints associated with conventional pumped storage, opening a much larger range of potential sites and enabling installations at a smaller, more distributed scale.
To commission its first grid-scale demonstrator, RheEnergise needed to scale the manufacture of its proprietary fluid from around 0.5 tonnes produced in total during development to a reliable operational process capable of producing 5 tonnes per day. Throughout this scale-up, product quality, process reliability and operational safety had to be maintained.
42T’s solution
42T designed and delivered the fluid-production capability required to support the commissioning of RheEnergise’s 500 kW demonstrator.
Using a risk-based engineering approach, the team identified the key technical challenges associated with scaling fluid manufacture from laboratory production to operational deployment. 42T then developed the process design, manufacturing strategy and implementation plan, drawing on expertise in fluid systems, manufacturing innovation, automation and process engineering.
42T delivered the design and specification of a large-scale fluid-mixing plant, complete with a semi-automated control system incorporating process automation, safety systems and an intuitive operator interface. By combining bespoke engineering with carefully selected off-the-shelf technologies, 42T delivered a practical, cost-effective production system designed for safe, reliable and repeatable operation by non-specialist personnel.
By taking ownership of fluid-production scale-up, process design and automation, 42T provided RheEnergise with the production capability required for commissioning while helping maintain progress against an ambitious eight-month delivery timeline.
“Commissioning our 500 kW demonstrator is a major step in proving our unique approach as a practical LDES solution. 42T’s process design and automation experience has been vital in getting us to this point, and validating our fluid-production method under real-world conditions. As grids move towards 100% renewables, dependable long-duration storage like this will be essential.”
Why 42T
Scale-up expertise
Bridging the gap between laboratory development and operational deployment.
Cross-disciplinary engineering
Combining process engineering, automation, manufacturing scale-up and quality engineering within a single team.
Practical delivery
Developing cost-effective solutions that balance performance, risk and programme constraints.
Peter leads business development and strategy across 42T’s innovation and product development programmes, combining deep technical expertise with strong commercial insight.
Ellie supports multidisciplinary innovation and product development, combining structured innovation techniques with hands-on engineering experience across healthcare and renewable energy.
