First Bus has expanded its work on battery energy storage in partnership with Palmer Energy Technology, a move that is anchored by installation of a turnkey 4.2MWh, 2.15MW system and transformer at the operator’s Aberdeen depot.
The burgeoning relationship will support fleet electrification by the operator. Its Aberdeen business runs battery-electrics from Wrightbus and Yutong. In 2025, sister business FirstGroup Energy took a lead investor position in Palmer Energy Technology.
The supplier has end-to-end responsibility for system supply, civil works, engineering and commissioning of the Aberdeen project. That is described as an important milestone in the delivery capability of the business, which was founded by automotive leader Dr Andy Palmer and Wei Shao.
In parallel, Palmer Energy Technology is delivering around 500kWh of battery storage at four other First Bus sites. That will capture surplus solar generation, reduce emissions, and optimise exposure to time-of-use energy tariffs, lowering costs. Those sites are expected to go live this month.
Central to the Aberdeen installation is Brill Power’s battery and energy management system. That platform enables optimisation of battery operation in real time, maximising usable energy capacity, extending lifetime, and improving overall system efficiency.
By dynamically balancing battery performance and intelligently managing charging and discharging behaviour, the Brill Power platform helps to unlock greater operational and commercial value from the asset over its lifetime.
The Aberdeen work represents a first for Palmer Energy Technology via the installation of a transformer free of sulphur hexafluoride (SF6). It is among the first of its kind to be deployed in the UK.
Alongside supplying the battery system, Palmer Energy Technology is designing and manufacturing the transformer, a capability that the business is now bringing to market as part of its broader offering. Commissioning is expected early in Q2 2026.
The project also supports wider First Bus exploration of second-life battery applications where energy storage retired from on-road use can be repurposed to static utilisation.
Head of Construction David Seaton adds that the partnership is helping First Bus to explore how battery storage and intelligent energy management can support operational efficiency and grid stability.
“The Aberdeen project is particularly exciting, not only because of its scale on a constrained site, but because it demonstrates the kind of innovative, lower-carbon infrastructure solutions that will be needed to support the transition to net-zero transport.”
Adds Dr Palmer: “This programme with First Bus reflects the direction of travel for Palmer Energy, combining storage and grid support at meaningful scale.
“Taking full responsibility for delivery on our largest project to date is a strong endorsement of our technical depth, and the introduction of SF6-free transformers signals how we intend to push cleaner infrastructure into the mainstream.”
