Cranfield University



Cranfield University is a postgraduate research university specialising in science, engineering, design, technology and management. The University was investigating ways to decarbonise their high energy use at their Bedfordshire campus. Using a £5 million grant received from the Public Sector Decarbonisation Scheme, the University introduced a range of measures.

Primarily the site wished to reduce reliance on their gas-combined heat and power system by replacing it with a new air source heat pump installed on the district heating network. The University also had an existing solar farm on site. The farm was installed in 2018 with the goal of generating 5% of the campus’s annual usage and was due for expansion. They therefore saw the value of installing battery energy storage on site to maximise the use of solar power and create its own building energy management system.



Cranfield University is a large campus site. After reviewing the site and understanding Cranfield’s objectives – primarily to maximise their solar generation on site and to minimise the increase in electrical demand from the air source heat pump – it was decided to install three battery energy storage systems.

The systems work together to allow the site to balance its energy across its own private network and help the University to overcome grid constraints.



Three 300kW battery storage systems were installed at three separate locations. Working independently but linked through our back office software to work as a team. The systems work on a schedule which was set at the start of the project. They allow the storage systems to take excess solar generation at key times of the day and then deliver that power back to the campus when generation stops. Two of the systems connect directly into the site’s 40 electricity transformers to provide power to energy intensive equipment.

What was particularly important to Cranfield University and to other organisations with challenging Climate Strategy and Action Plan targets, is that a Connected Energy system is made from used car batteries. Each contains 24 used Renault Kangoo vehicle batteries. While operationally identical to units made from brand new batteries, these second life storage units provide a positive carbon benefit of 450tCO2e for every 1MWh installed compared with a first life energy storage unit. 

"This is the start of completely reimagining how we balance our energy onsite. We will be using the batteries in a number of different ways to help us smooth out the energy interactions between the solar farm, the air source heat pump, the gas CHP, and the import of energy." - Gareth Ellis, Cranfield University’s Energy and Environment Manager