About the Project
Flexible Railway Energy Hubs will demonstrate a transformative approach to accelerate the decarbonisation of the single largest electricity consumer, Network Rail. An Energy Hub is a modular microgrid solution that integrates batteries and local renewable energy with the rail traction network. By transforming the railway into a flexible electricity consumer, the project generates benefits to the electricity network and consumers by reducing wind curtailment expenses via flexibility services and reducing engineering disturbances.
Project Objectives
Our microgrid approach will be the first scaled demonstration of a battery powered microgrid that couples two large complex networks, rail, and electricity, facilitating cross-sector decarbonisation.
Hubs will use the railway traction power network as a conduit for delivering flexibility and ancillary services to the electricity transmission network. The “reach” of the traction power network gives access to a wide range of low-cost sites for battery storage and solar panel locations. The traction power network also reaches regions experiencing significant wind curtailment, where Hubs offer significant wind curtailment reduction potential.
Through simulation modelling and predictive control, Hubs will mitigate unwanted interactions of power electronic devices between electricity grid and the railway network as demand grows, while also reducing voltage drops at weak spots around the grid and improving voltage stability.
Benefits for the Customers & SP Energy Networks
The rail network is already the UK’s largest electricity consumer (4.2TWh p.a. ~1.2% of total UK demand, emitting 1.2 million tCO2e). At present this single largest electricity consumer is not flexible, without benefits for the electricity system or the rail system.
Diesel trains consume 648 million litres of diesel per annum, emitting an additional 1.8 million tCO2e. Replacing diesel trains with electric trains would nearly double rail electricity demand, requiring 448km of track to be electrified every year to meet the net zero target by 2050, representing over £30bn investment. The lead time for critical new projects to be connected to the grid is currently up to 15 years, implying a high risk of delayed railway electrification.
Benefits of the Energy Hubs
The Hub project is an innovative engineering demonstration which aims to create a blueprint for accelerating decarbonisation of major UK electricity demands. The project also balances commercial and regulatory considerations, with staged outcomes. The project will also verify our forecasts of significant and tangible benefits of up to £2 billion by 2070, including reduced construction costs and investment in conventional grid reinforcement; reduced electricity bills and network outages.
Benefits from Hubs are based on roll out to 390 rail sites (out of over 2600 rail stations, depots, and traction power feeder stations in the UK). The benefits comprise:
For Electricity Network Operators:
Reduced Wind Curtailment costs. The full-scale roll-out option provides aggregated battery storage of 1.9 GWh to alleviate transmission network constraints for the electricity operator and customers. The annual benefit to the electricity customers will reach £15.7m from 2043, with the cumulative benefit of £535m by 2050.
Benefits from Demand Flexibility Service. The capability to provide demand flexibility services has become increasingly important for the electricity network. In 2022, the ESO launched a new Demand Flexibility Service (DFS) for the winter period to access additional flexibility when the national demand is at its highest. By 2043, when all the Hubs are built, the railway network will have a capacity of 1.9GWh battery storage to provide flexibility services to the power grid, bringing a further £27.43m annual benefit to our customers.
Carbon Emission Reduction. The Hubs will result in carbon emission reduction of 282k tCO2e in the first 10 years, and the total whole life carbon emission reduction will reach 1,552k tCO2e by 2070.
For Railway Industry as the major demand:
Avoided Overhead Line Construction CAPEX. The Hubs can be used to decarbonise 2,700 stk in rural areas, avoiding /overhead line electrification. The overall benefit is projected to reach £2.7bn at a very conservative saving of £1m/stk.
Savings by Time Shifting Electricity Use. The storage in the Hubs will also bring savings to the railway customers by charging batteries during the nighttime and bridge the energy gap in the daytime to power the traction load, leading to additional £29.72m annual OPEX savings for railway customers by 2043.
Outputs
Output 1 (O1): Hub design specifications for the Ayr depot and the tertiary control specification report
O2: Digital simulation of the Hub and user interface to display the services of Hubs
O3: Hub demonstrator commissioned and live trial of the system functionalities at the Ayr depot
O4: Report on demonstrator data analysis and evaluation of operational, economic, and environmental impacts of the live demonstrator
O5: Report on stakeholder mapping and dissemination activities
O6: Report on commercialisation and rollout model, CBA model and the BAU transition.