THE world’s first grid-scale pumped heat energy storage (PHES) system has been assembled and commissioned by the technical team at the Sir Joseph Swan Centre for Energy Research at Newcastle University.

This facility includes a grid-coupled energy PHES electricity storage technology rated at 150kW and able to store up to 600kWh of electricity.

With its supporting R&D infrastructure, this now puts the UK in a world-leading position in the research and development of low-cost and grid-scalable electrical and thermal energy storage.

Originally developed as part of the Energy Technologies Institute (ETI) Distribution Scale Energy Storage Project, this technology seeks to store electrical energy produced from renewable solar or wind energy sources and then to make it available to electrical energy consumers when they need it.

In 2016 the ETI entered into an agreement with the Sir Joseph Swan Centre to take the technology further and demonstrate its exciting potential.

Professor Tony Roskilly, director of the Swan Centre for Energy Research, said: “Pumped Heat Energy Storage or Pumped Thermal Energy Storage is cheap and is compatible with the technical and scale-up challenges of grid-scale energy storage.

“Given the thermal power cycle’s enormous potential, there has been a tremendous amount of research and commercial interest in PHES technology over the last ten years, however until now nobody has managed to get as far as to demonstrate a real-world working system.

“What is exciting is that the UK is the first to do it and as such, is now leading the world in what looks like a highly disruptive and cost-effective technology which can balance renewable energy supply and demand.”

During recent testing, the 150kW reversible heat pump/engine was operated in compression and expansion modes i.e. as a heat pump and a heat engine, with evidence to support sub-second charge/discharge mode switching.

Dr Andrew Smallbone, co-director of the National Facility for Pumped Heat Energy Storage, said: “Our initial tests have been very promising, we can very quickly change our system control from charge to discharge in a few milliseconds. The analysis of system performance indicated that the current system operates with an efficiency which yields a round trip efficiency of 60-65 per cent.

“This figure is very exciting as it’s consistent with the original target design specification and as our recent work on Levelised Cost of Electricity Storage shows is already sufficiently high enough to put the technology in the mix for being the lowest cost and most flexible grid-scale energy storage technology. Additionally, these tests also indicated there is significant opportunity for further improvements through design enhancements and operational optimisation. This will now continue over the next few months.”