How we make, deliver and use energy is under scrutiny like never before. But there’s one thing most people agree on. To reach net zero, cut costs and boost energy security we must urgently electrify transport and heat – and generate clean electricity to power them.

This is not without its challenges, not least that our current electricity system wasn’t designed with millions of electric vehicles (EVs), heat pumps, wind farms and solar panels in mind. A distributed energy system is on its way, creating the opportunity to reimagine how we do things, and build smart, local energy systems.

Local authorities are on the front-line of this transition in the UK, and Oxford City Council is showing real leadership. It has set an ambitious target to be net zero by 2040 and, thanks to Energy Superhub Oxford, it is transforming how its citizens heat their homes, travel to work and power their lives.

Smart power infrastructure 
Energy Superhub Oxford is a four-year project part-funded by government under the ‘Prospering from the Energy Revolution’ programme.

Delivered by a consortium of six companies led by EDF Renewables and Oxford City Council, the £41mn initiative aims to show how public-private sector partnerships can innovate to decarbonise power, transport and heat, benefit local communities and accelerate net zero.

It will save 10,000 tonnes of CO₂ every year, equivalent to taking over 2,000 cars off the road, increasing to 25,000 tonnes by 2032. Ultimately the goal is to create a blueprint for towns and cities across the UK to cut carbon and improve air quality.

What makes the project unique is that its core components make use of a direct, 33 kV connection to National Grid’s transmission network, instead of the local distribution network. This helps to alleviate strain on the local grid and reduces the need for costly upgrades, while making more efficient use of the UK’s existing high voltage power network.

It is an approach first conceived by Pivot Power (now part of EDF Renewables) to support the integration of renewables and enable mass-scale rapid EV charging at strategic locations up and down the country.

Hybrid battery storage 
At National Grid’s Cowley substation, to the south-east of the city, EDF Renewables has installed a cutting-edge hybrid battery, combining a 50 MW/50 MWh lithium-ion battery with a 2 MW/5 MWh vanadium flow battery. The lithium-ion battery went live in June 2021, and the vanadium flow battery has been online since July 2022.

The goal is to test how the high-power capabilities of a lithium-ion battery can be combined with the heavy-cycling, non-degrading characteristics of the flow battery to support more renewables, increase grid resiliency and create a smarter, more flexible system.

The battery sits at the heart of the project. By providing ancillary services to National Grid and trading electricity in wholesale markets it helps to pay for the connection to the transmission network and support more renewables, which in turn unlocks the capacity needed to provide mass-scale, rapid EV charging locally.

Aerial shot of National Grid’s Cowley substation, to the south-east of Oxford, showing both vanadium flow and lithium-ion battery systems 
Photo: Energy Superhub Oxford

Driving Oxford’s EV revolution 
The battery shares its connection to the transmission network with a high-voltage underground cable, delivering power directly to a massive public EV charging hub at Redbridge Park and Ride, four miles from Cowley substation.

While the site has opened with an initial 42 charging bays, thanks to the connection it has up to 10 MW of installed capacity, enough to charge up to 400 cars simultaneously. It brings together three different chargepoint operators at one location, and has been designed to cater for all needs, so that drivers can charge and be on their way in minutes, or while they visit the city centre and go about their day.

The Oxford Superhub offers charging for 42 cars at once: 10 Fastned charging bays – up to 300 kW; 12 Tesla charging bays – up to 250 kW; and 20 Wenea charging bays – 7–22 kW.

Aerial view of the Redbridge Park and Ride station 
Photo: Energy Superhub Oxford

The network can be expanded to other strategic charging locations in Oxford along the privately installed cable, including bus depots, taxis and commercial fleets, supporting Oxford’s net zero 2040 target, as well as providing the charging infrastructure needed for the pilot Zero Emission Zone – a first-of-its-kind scheme that applies fees to any non-electric vehicle entering the central zone.

EDF Renewables has already installed a substation at Oxford Bus Company’s Watlington Road depot, ready to support the company’s plans to introduce over 100 electric buses in the coming two years.

In parallel, Energy Superhub Oxford has financed the electrification of 40 of Oxford City Council’s 330 vehicle fleet, from cars and vans to road sweepers and a refuse collection vehicle. These vehicles are providing valuable insights to inform the council’s ongoing fleet electrification strategy. The project has also provided funding to support the city’s Hackney Carriage (taxi) drivers to make the switch to EVs.

Low carbon heating 
While the UK recently hit the one-million milestone for EVs, progress on weaning the nation off gas-fired heating remains frustratingly slow. To this end, Energy Superhub Oxford has supported the installation of over 60 ground source heat pumps at social housing properties in and around Oxford, helping to alleviate the reliance on fossil fuel-based heating.

This has involved a three-step process, first evaluating the benefits of replacing electric storage heaters with heat pumps; second, using the building fabric to shift the load by several hours; and then finally by adding a new, pioneering integrated heat battery. This allows heating to be shifted by many more hours, reducing the load on the grid at peak heating times and offering the opportunity for significant savings by combining with time-of-use electricity tariffs.

‘The Energy Superhub Oxford is an example of how our transmission network can act as a catalyst for the decarbonisation of society. The high voltage connection provides the power to help electrify transport and reduce emissions, as well as deliver a battery storage facility to help manage peaks and troughs in demand for electricity.’ – Roisin Quinn, Director of Customer Connections at National Grid Electricity Transmission

Residents have reported running cost savings of over 50%, while the five properties trialling the flexible storage heat pump technology are expected to show that heat pumps could be up to one-third cheaper than gas boilers to run.

The project is evaluating adoption and usage, to understand how heat pumps benefit local residents and how we can reduce future electricity bills as heat pump installations scale from thousands to millions over the next decade.

Innovation versus regulation 
A project like this is exploring new approaches to how battery storage, charging infrastructure and heating can be delivered, and how flexibility can support a future UK energy system.

But, with innovative approaches there will always be barriers and Energy Superhub Oxford has met its fair share along the way. Both in transmission charging structures and in renewable heating we have faced real challenges in overcoming existing regulatory structures and funding models to deliver this project. There are valuable lessons to be learned if we are to create a truly flexible and efficient energy structure for a net zero UK.

Roadmap to net zero 
Energy Superhub Oxford provides a vision of the future, today. By delivering a world-leading project that cuts emissions across transport, power and heat, we are breaking new ground to help the UK reach net zero sooner.

Already its approach is being replicated, with construction underway at EDF Renewables’ next two Superhubs in Coventry and Birmingham. Like Oxford, these projects combine transmission-connected grid-scale storage and EV power infrastructure to deliver national benefits and local opportunities, creating the low carbon infrastructure needed to accelerate net zero and power more of our lives with clean energy.