Mercia Power is also developing grid-scale Battery Energy Storage Systems (BESS) to complement our existing gas-fuelled power stations.

In 2019, the UK government committed into law a Net Zero emissions target for the UK by 2050. Renewable generation, mainly provided in the UK by solar and wind, is both intermittent and unpredictable. With the decommissioning of traditional sources of baseload energy for the grid, such as coal and nuclear, power response sites are essential to filling the gaps.


We consider our battery assets as vital infrastructure for the UK. Energy storage is key to improving our energy security and successfully reaching net zero, two items that are inked at the top of everyone’s agendas. Our batteries will support the Grid in coping with the variability of renewable power supply as we transition to a greener energy mix, ensuring the necessary power is provided to keep the lights on in homes and businesses across the UK.

Graham White, CEO of Mercia Power Response

Mercia’s batteries will be used to store electricity when there is excess power, typically during high wind low demand periods (e.g. at night) and discharging during periods of high demand (e.g. during the day). This supports the Grid in managing the supply and demand of electricity across its network and helping to fill shortfalls when there is not enough renewable energy to satisfy demand. This will ensure that power is provided quickly and efficiently to households and businesses across the UK and maximising the delivery of energy to consumers from Net Zero Carbon sources.



Electricity storage capacity increases in all scenarios to ensure peak demand can be met reliably as an increasing proportion of our electricity is generated from weather dependent renewables. We need somewhere to store excess energy at times of high renewable generation, and somewhere to get energy from when demands are high and generation output is low.

National Grid’s Future Energy Scenarios (2022)



Battery Energy Storage Facilities - Case Studies

Mansfield Road Project

Size: 30MW
Location: Retford, Nottinghamshire

Darnall Road Project

Size: 40MW
Location: Sheffield, Yorkshire

Carlisle Road Project

Size: 40MW
Location: Sheffield, Yorkshire


A secure energy supply is vital for economic growth and would enable the transition to renewable energy whilst ensuring a reliable fossil fuel backup energy supply. Gas reciprocating engines are a uniquely placed technology, as they can respond to grid needs within seconds and potentially be transitioned to low-carbon fuels, such as Hydrogen, in the future.

Our engines are Hydrogen ready. The fuel-switch from natural gas to hydrogen will enable decarbonisation and will have long-term positive environmental, social and economic impacts by reducing dependency on fossil fuels.

As electricity cannot be stored in useful quantities, National Grid requires a range of ‘back-up’ balancing services because at certain times of the day reserve power in the form of either generation. Our Gas Reciprocating Engine sites provide a backup energy supply for when energy demand is greater than forecasted demand and/or plant unavailability.

We typically build and operate 5-8MW generation plants connected to localised 11kV networks, enabling us to provide energy quickly and efficiently to households and businesses, delivering strong returns to our investors.

Gas Reciprocating Engines - Case Studies

Fulwood Road

Size: 10.2 MW
Number of Engines: 3
Grid Connection: 11kV
Operational: December 2021

Graphite Way

Total Size: 18.0 MW (3 x 6.0 MW Sites)
Total Number of Engines: 12 (3 x 4 Engine Sites)
Grid Connection: 11kV
Operational: A: Nov 2018 | B: Jan 2019 | C: July 2019


Size: 7.9 MW
Number of Engines: 3
Grid Connection: 11kV
Operational: TBC