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First Bus trials electric depot charging that adjusts to grid demand in Glasgow
2026-05-19, Moovit News Team
First Bus Depots Join Grid Balancing Trial
First Bus has begun a trial using electric bus depots to help balance the UK’s electricity system by adjusting when vehicles charge, marking the first time a UK bus operator has enrolled in the National Grid balancing mechanism. The trial, which started at the company’s Glasgow depot, will extend to its Great Yarmouth facility in Norfolk later this spring. The system increases charging demand when excess renewable energy is available and reduces it during peak periods, helping to avoid wasted generation and support grid stability.
Reducing Renewable Energy Waste
The initiative addresses a growing challenge in the UK’s energy system: managing surplus renewable generation, particularly wind power in Scotland. By charging buses on a more flexible schedule in response to real-time grid signals, First Bus aims to absorb excess clean energy that might otherwise be curtailed. The approach also supports a more efficient energy network by reducing demand during peak periods, when the grid is under greatest strain. Isabel McAllister, Chief Sustainability Officer for First Bus, said electric buses can play an active role in the UK’s energy system by charging when the grid needs them to, reducing wasted renewable energy, supporting system stability, and improving the economics of electrification.
Partnership with Optimo Energy
The trial is being delivered in partnership with Optimo Energy, whose platform enables operators to optimize charging in response to real-time grid signals while ensuring vehicles remain ready for service. First Bus operates over 1,400 zero-emission vehicles, representing one of the UK’s largest electric bus fleets. The company has committed to operating a fully zero-emission commercial bus fleet by 2035 and plans to develop 20 electric depots across the UK, with several more due to be completed by 2027. First Bus has also opened its depot-based charging infrastructure to third parties through its First Charge offering.
Expanding the Trial
The Glasgow depot trial will be followed by the Great Yarmouth depot in Norfolk later this spring. The trial will explore how depots can participate in additional energy flexibility markets, potentially creating new revenue streams while supporting the transition to net zero. The National Grid balancing mechanism aims to balance electricity supply and demand before electricity delivery, and First Bus’s participation represents a new model for how transport infrastructure can contribute to energy system resilience.
Planning Around Grid-Responsive Charging
Riders using First Bus services in Glasgow and Great Yarmouth should see no impact on vehicle availability, as the charging optimization system is designed to ensure buses remain ready for scheduled service. The trial demonstrates how electric bus operations can align with broader energy system needs without compromising transit reliability. Passengers can use Moovit to check real-time schedules and plan journeys across First Bus routes as the company continues expanding its zero-emission fleet and grid-responsive charging capabilities.