Veolia, working through its specialist energy team, has commissioned a new Battery Energy Storage System (BESS) for the 500-bed Rotherham Hospital as part of a 20-year Energy Performance Contract (EPC).

The 500kWh storage capacity will contribute to targeted EPC savings of over £1m a year, provide an energy income, increase resilience of the energy supply, and enable Rotherham NHS Foundation Trust to cut carbon emissions by 49,620 tonnes.

The EPC used by the trust is the NHS standard performance contract, managed, procured, financed and monitored for its lifetime by the Carbon and Energy Fund.

Balancing demand

The battery system effectively balances the output of renewable energy sources which operate in a less-predictable manner compared to traditional power stations.

When discharging at peak time, the battery displaces the marginal generator which is still fossil-fuelled power for most of the year.

In this way it will perform a key role in the transition to a sustainable decarbonised electrical supply.

The BESS comprises multiple battery cells that store electrical energy produced for use at a later time.

Based on the latest lithium-ion technology the battery unit is capable of delivering 500kWh, equivalent to the energy output from 130,000 standard AA-size batteries.

Reducing energy bills

The technology enables the trust to take advantage of reduced electricity bills by discharging power when the demand is highest, which reduces imported electrical consumption and peak electrical import charges.

And, because of its unique reaction speed, and fast-acting controls, it provides continuous stability for the National Grid by adjusting power flows at each millisecond to balance the surplus, or lack of energy, on the network. 

Engineered into the electrical infrastructure and CHP system by Veolia, the BESS enables the trust to gain income from the grid by exporting power when there is less being generated than used by consumers, and also for absorbing power when more power is being generated than is being used.

Achieving net-zero carbon will require a sustainable energy supply that can replicate and replace fossil-fuelled power stations

This reduces electrical bills via the BESS’s ability to discharge power at these key times and reduce imported electrical consumption and import charges.

And this adds to the financial benefit gained from the fast-frequency response through grid stabilisation.

Supply resilience

Control takes place automatically via a third-party aggregator, which manages electricity assets to counter load imbalances in response to changes in energy demands.

By operating in an Uninterruptible Power Supply (UPS) mode the system also delivers greater electrical power supply resilience for critical healthcare activities, such as operating theatres, by providing power if grid supply is lost.

Commenting on the project, John Abraham, chief operating officer at Veolia UK and Ireland, said: “Achieving net-zero carbon will require a sustainable energy supply that can replicate and replace fossil-fuelled power stations.

“To do this we believe flexibility and demand management of decentralized energy is the key to addressing this issue.

“Backed by the energy saving upgrades that are part of the energy performance contract, the new BESS at Rotherham Hospital is another key step in achieving this goal, and helps the NHS to become more sustainable and focus budgets on patient care.”