IN Brief:
- SP Energy Networks is deploying TUAL PowerUp charging at Middlewich, Liverpool, and Cambuslang following an initial trial.
- Integrated battery storage supports high-power DC charging without requiring the same scale of immediate site reinforcement.
- The rollout will test battery-buffered charging across operational depots where fleet availability and infrastructure flexibility are critical.
SP Energy Networks is extending battery-buffered electric vehicle charging across three operational sites following a successful trial of TUAL’s PowerUp Charger at its Middlewich depot in Cheshire.
The electricity network operator will deploy the technology at Middlewich, Liverpool, and Cambuslang near Glasgow as it increases the number of electric vehicles used by operational teams. PowerUp combines stationary battery storage with high-power DC charging, allowing charging capacity to be added where extensive conventional site upgrades or civil engineering would otherwise present difficulties.
Depot electrification often exposes a difference between available electrical energy and available electrical power. A site connection may be capable of supplying enough energy to recharge vehicles over several hours while lacking the instantaneous capacity needed to run high-power chargers directly from the network when vehicles return together.
A battery buffer can absorb energy at a lower rate over a longer period before supplying a higher rate to vehicles during charging sessions. Total electricity consumption remains, but the peak demand seen by the site connection can be altered by moving energy through the stationary battery.
SP Energy Networks says the technology is particularly relevant where existing infrastructure, site limitations, or future development plans make conventional installations more difficult. The company also highlighted the ability to relocate the equipment if site requirements change, avoiding some of the permanence associated with a substantial fixed reinforcement scheme.
The Middlewich trial demonstrated that the system could be deployed quickly and deliver the required DC charging capability for operational vehicles. SP Energy Networks also says the integrated battery supports operational resilience, although the announcement does not specify that the charger can operate as an islanded backup supply during a network outage.
That leaves fleet readiness as the central operational requirement. Network vehicles may be required for fault response, maintenance, restoration, and emergency work at short notice, giving the operator less tolerance for a charging system that depends on vehicles remaining parked for long periods.
Battery buffering provides another variable in the design, but it does not make connection planning disappear. The stationary battery still has to receive enough energy between charging sessions, and repeated high-power vehicle demand can eventually exhaust the buffer if its recharge rate and stored capacity are insufficient for the fleet duty cycle.
Vehicle arrival times, daily mileage, charger utilisation, stationary battery capacity, connection rating, and the required reserve for unexpected call-outs therefore determine whether the architecture works at a particular depot. A design based solely on charger nameplate power can overlook the energy that has to pass through the site across an entire working day.
The electrical installation adds power conversion, switchgear, protection, controls, communications, isolation, thermal management, and battery safety requirements. Those components have to operate alongside the existing depot supply while keeping charging available to vehicles without exceeding agreed network limits.
Stationary batteries introduce degradation and conversion losses as well. Their commercial value depends on whether the avoided or deferred electrical works, installation flexibility, and fleet-operating benefits outweigh the cost of the storage equipment and the additional cycling imposed by regular charging duty.
The approach contrasts with larger fleet sites where permanent network reinforcement is already justified by vehicle numbers and long-term use. Liverpool’s Gillmoss bus depot electrification, for example, involved upgraded grid connections and intelligent high-power charging infrastructure for more than 100 battery-electric buses.
Software-led flexibility provides another option where vehicles remain connected for sufficient periods. An ev.energy aggregation programme has enrolled 10,000 charging assets into British flexibility markets, shifting charging demand through control software rather than using a stationary battery to reshape the site’s power profile.
Neither architecture is universally preferable. Scheduled charging can be effective where departure times offer substantial flexibility, while a buffer can be useful where vehicles need higher charging power than the grid connection can provide directly. Larger depots may ultimately combine reinforcement, smart charging, storage, and local generation rather than relying on one method.
Public infrastructure statistics provide only partial visibility of this electrical workload. The Department for Transport counted 121,171 public EV chargers across the UK on 1 July 2026, including 28,887 rated at 50kW or above, while many private workplace and fleet installations sit outside the public network totals.
Commercial fleets can concentrate substantial load at relatively few locations. Distribution operators therefore have to accommodate charging growth while customers decide whether to reinforce connections immediately, accept flexible arrangements, alter operating schedules, or install behind-the-meter equipment.
SP Energy Networks occupies both sides of that calculation as a network operator electrifying its own vehicle fleet. The Middlewich, Liverpool, and Cambuslang deployments will provide operating experience of battery-buffered charging at sites where vehicle readiness, connection constraints, and infrastructure flexibility have to coexist rather than being considered as separate problems.
