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Projects: Projects for Investigator
Reference Number	EP/J006246/1
Title	Pumped Thermal Electricity Storage
Status	Completed
Energy Categories	Other Power and Storage Technologies(Energy storage) 100%;
Research Types	Basic and strategic applied research 100%
Science and Technology Fields	ENGINEERING AND TECHNOLOGY (Mechanical, Aeronautical and Manufacturing Engineering) 100%
UKERC Cross Cutting Characterisation	Not Cross-cutting 100%
Principal Investigator	Dr AJ White No email address given Engineering University of Cambridge
Award Type	Standard
Funding Source	EPSRC
Start Date	01 June 2012
End Date	31 July 2016
Duration	50 months
Total Grant Value	£318,325
Industrial Sectors	Energy
Region	East of England
Programme	Energy : Engineering
Investigators	Principal Investigator	Dr AJ White , Engineering, University of Cambridge (99.999%)
	Other Investigator	Dr GT Parks , Engineering, University of Cambridge (0.001%)
	Industrial Collaborator	Project Contact , Scottish and Southern Energy plc (0.000%) Project Contact , Isentropic Ltd (0.000%)
Web Site
Objectives
Abstract	The increasing use of renewable energy technologies for electricity generation, many of which have an unpredictably intermittent nature, will inevitably lead to a greater need for grid-scale electrical energy storage schemes. The UK government's target (as part of the EU Renewable Energy Directive) is for 20% of energy to come from renewable sources by 2020. This will require a much a higher proportion of electricity to be generated from uncontrollable sources such as wind, and one of the associated challenges will be providing sufficient electricity storage capacity to deal with the resulting variability in supply. Currently there is about 30 GWh of electricity storage capacity in the UK, with a maximum power output of around 3 GW. Nearly all of this is in the form of Pumped Hydro Storage (PHS), which is expensive and its scope for extension is limited by geographical constraints. Estimates vary, but the expert view is that our storage inventory will need to at least double over the next decade or so in order to efficiently accommodate the expanding fraction of wind and other renewable generation technologies. There is thus strong motivation to develop new, efficient and cost-effective electricity storage methods.This project is aimed at investigating a novel storage technology known as Pumped Thermal Electricity Storage (PTES). PTES uses a high temperature-ratio heat pump to convert electrical energy into thermal energy which is then stored in two large reservoirs - one hot and one cold. The reservoirs contain gravel, or a similar high heat capacity material, and are able to store the energy much more compactly than PHS. When required, the thermal energy can be converted back into electrical energy by effectively running the heat pump backwards as a heat engine. The projected round-trip efficiency is approximately 75%, which is a little lower than PHS, but PTES has a number of potential benefits, including low capital cost and no geographical constraints. Compared to chemical energy storage methods (batteries and flow batteries) it also has the advantage of not requiring any hazardous or scarce substances.The success of PTES will hinge upon minimising the effect of various thermodynamic irreversibilities (for example, heat transfer across substantial temperature differences and losses associated with compression and expansion of the working fluid) whilst simultaneously keeping capital costs low. Accordingly, the proposed work focuses on investigating fundamental thermodynamic, fluid flow and heat transfer processes using a combination of experimental, theoretical and computational methods. An important aim of the work is also to develop and validate an overall system model and to use this to optimise the design and operation strategy, and to examine the benefits that PTES might bring to the electricity supply chain
Publications	(none)
Final Report	(none)
Added to Database	05/03/12