V2G for UK Fleets: When to Pilot and What £4,000–£6,000 Buys
V2G can turn depot EVs into flexible energy assets that reduce depot energy costs and, for the right fleets, generate material revenue. Overnight-dwelling fleets with predictable schedules stand to gain the most, according to evidence from Cenex’s Project Sciurus trial. If your vehicles sit idle for hours at a depot each night, V2G deserves a serious look.
TL;DR:
Fleets with predictable, long overnight dwell times benefit most from V2G, as they can confidently participate in grid services without risking vehicle availability.
Revenue potential varies across markets, with ancillary services offering lower cycling and risk, while energy arbitrage can generate higher returns but faster battery wear.
Compatibility issues, especially support for ISO 15118-20, and contractual terms with aggregators are key technical and operational risks to address upfront.
Implementation costs for V2G hardware have decreased significantly, with recent chargers costing about £4,000 to £6,000 per unit, depending on site complexity.
Prioritizing depot energy management through load balancing, solar, and storage before V2G maximizes project feasibility and reduces dependence on fluctuating grid revenue.
Table of Contents
Revenue streams and business models fleets can access with V2G
Practical implementation: site assessment, typical costs and deployment options
Evidence: case studies and modelling that show fleet outcomes
Data management and cybersecurity considerations in vehicle-to-grid systems for fleets
How Swift Charging can help fleets evaluate and deploy V2G-capable infrastructure
How V2G works and why fleets are well suited
Bidirectional charging lets an electric vehicle’s battery send power back to the grid or building, not just draw it. Smart charging, known as V1G, only adjusts when and how fast a vehicle charges. Vehicle-to-grid (V2G) goes further and exports stored energy, while vehicle-to-home (V2H) and vehicle-to-building (V2B) send that same power to a home or commercial building instead of the wider grid.
Fleets suit this better than individual drivers because depot vehicles follow repeatable schedules and sit connected for long, known periods. A single van parked overnight offers modest value. Thirty vans parked overnight at the same depot, all wired into one charge point management system, become a coordinated battery bank an operator can schedule with precision.
That aggregation matters commercially:
Predictable dwell times mean chargers can commit to grid services without risking a vehicle being unavailable for its next shift.
Centralised control through one charge management platform removes the need to coordinate with individual drivers.
Combined battery capacity across a fleet reaches a scale that makes participation in wholesale or ancillary markets viable.
Revenue streams and business models fleets can access with V2G
Fleet V2G revenue comes from several distinct markets, and not all pay the same or carry the same risk.
Ancillary services, such as frequency response, pay for battery capacity being available to the grid operator, often with lower cycling demands than other options.
Energy arbitrage earns money by charging when electricity is cheap and discharging or avoiding purchase when prices spike, but it cycles the battery harder.
DNO or local flexibility markets pay fleets to reduce demand or export at specific times to relieve strain on the local network.
Tariff optimisation shifts charging to off-peak periods and can cut energy costs without any grid export at all.
Most fleets access these markets through an aggregator, who bundles capacity from many sites and takes a share of the revenue in exchange for market access and settlement handling. Contract terms vary widely on availability requirements, penalty clauses and minimum notice periods, so read them carefully before signing.
Revenue tends to be most material for fleets with reasonable scale, high charger availability during grid-stress windows, and access to more than one revenue stream rather than relying on a single market.
Pro Tip: Ask any prospective aggregator how they split ancillary and arbitrage revenue, and whether that split changes if market prices fall.
Technical and standards checklist for fleet V2G projects
Interoperability, not battery chemistry, is usually what decides whether a V2G project works. The IEA’s 2026 review of vehicle-to-grid technology notes that markets including the UK meet many of the conditions needed for V2G, but flags that ISO 15118-20, the standard governing vehicle-to-charger communication, remains unevenly implemented across hardware.
Before committing to a fleet V2G project, check:
Whether chargers and vehicles support ISO 15118-20, or have a confirmed firmware upgrade path if not, since this is a well documented source of plug and charge compatibility issues.
Which vehicles in your fleet are actually V2G capable now, since the compatible vehicle list is still narrower than V1G-only models.
Whether your charge point management system (CPMS) can talk directly to an aggregator’s platform for scheduling and settlement.
How metering and settlement will be handled, since inaccurate metering undermines any revenue claim.
Practical implementation: site assessment, typical costs and deployment options
Start with a site energy and dwell analysis. Pull vehicle telemetry and driver schedules to map exactly when vehicles arrive, how long they stay connected and how much spare capacity exists during that window. Our own operational-first approach to depot charging covers this groundwork in more detail, and partner tools such as EnerlyticsAI’s fleet analytics can help model dwell and usage patterns before committing capital.
Cost is driven by three things: the V2G-capable charger premium over standard AC or DC units, the complexity of the electrical installation, and whether you add battery storage (BESS) or solar PV. Cenex’s Project Sciurus reporting shows single-phase V2G hardware costs have fallen from an early figure near £15,000 including installation to a more recent premium in the region of £4,000 to £6,000. Our commercial installation cost guide breaks down the wider installation cost elements.
Three deployment patterns reduce grid upgrade risk:
A behind-the-meter DC hub that keeps most energy flow on-site rather than through the grid connection.
A selective AC V2G rollout on a handful of vehicles before scaling fleet-wide.
A combined PV and battery storage approach that reduces reliance on grid import in the first place.
Evidence: case studies and modelling that show fleet outcomes
The strongest UK evidence for fleet V2G comes from three sources. Project Sciurus found domestic participants earning up to roughly £80 a month in V2G credits under a simple OVO Energy proposition, with modelling suggesting potentially substantial annual household earnings under more favourable products. The 3ti V2X DC FastHub demonstration modelled an integrated DC microgrid combining PV, battery storage and bidirectional chargers, showing depot-level energy cost savings and peak demand reductions.
Evidence source | What it measured | Reported outcome |
Domestic V2G credits and modelled earnings | Up to £80 per month in credits; up to £725 per year modelled | |
3ti V2X DC FastHub (Cenex) | Depot PV, BESS and V2G integration | Peak demand reduction of 5 kW depending on site |
Co-optimised trip and charging scheduling | Seasonal revenue uplift varies with time of year, with per-EV annual revenues potentially substantial |
Academic modelling of British electricity scenarios found that co-optimising trip schedules with charging, rather than charging opportunistically, increases fleet V2G revenue substantially, with the biggest gains in summer months when ancillary demand is stronger. These UK government V2X innovation programme projects funded several of the trials behind this evidence base.
Risks, battery degradation and regulatory constraints
Battery wear is not uniform across revenue types. Ancillary services tend to cycle batteries less than energy arbitrage, so the mix of services you choose affects long-term battery health as much as raw usage does.
Watch for these before signing anything:
Aggregator contracts often carry availability penalties, so read notice periods and minimum uptime clauses closely.
Settlement timing can lag actual grid service delivery by weeks, which affects cash flow projections.
DNO engagement is worth starting early, since local network constraints can limit how much export capacity is available at your site.
Firmware lock-in from a single vendor can strand a project if that vendor exits the V2G market.
Data management and cybersecurity considerations in vehicle-to-grid systems for fleets
A fleet V2G system connects vehicles, chargers, a charge point management platform, and often an external aggregator, which means fleet and vehicle data now travels across several organisations rather than staying inside one depot’s network. Telemetry data covering vehicle location, state of charge, and dwell patterns is commercially sensitive, and giving an aggregator visibility into it is usually a condition of participating in ancillary or flexibility markets.
Before connecting fleet systems to a third-party platform, check how data is encrypted in transit and at rest, and who retains ownership of the usage data your vehicles generate. The IEA’s 2026 review points to multiparty interoperable standards, rather than single-vendor systems, as the more resilient path, partly because standardised protocols make it easier to audit who can access charging and discharging commands.
Cybersecurity matters here in a very practical sense: a compromised charger or CPMS with export control could, in theory, be used to manipulate power flow across an entire depot. Firmware that can be updated remotely and securely, rather than requiring a hardware swap, is one of the clearer safeguards against this. Ask any charger or CPMS vendor how they handle security patching, who can issue remote charge or discharge commands, and how access is logged. These questions belong in procurement discussions alongside ISO 15118-20 support, not treated as an afterthought once hardware is already installed.
Our view on where V2G fits in fleet electrification
We think most fleets should treat V2G as the second step, not the first. Get depot energy use right, through load management, PV and battery storage where it makes sense, before expecting meaningful grid revenue. That sequencing tends to produce a more bankable project and a smoother pilot.
Support is available to fleets through feasibility assessment, site surveys, charger procurement and long-term management, providing assistance to operators at each stage of that decision.
If you’re weighing up a feasibility pilot, we’re glad to talk it through.
— Swift Charging
How Swift Charging can help fleets evaluate and deploy V2G-capable infrastructure
Fleet electrification and V2G readiness both start with the same groundwork: knowing your depot’s power capacity, your vehicles’ schedules and what your electrical connection can support. Support can be offered from the early feasibility stage through to installation and ongoing management, providing a single point of contact rather than separate suppliers for each stage.
Our fleet-related services include:
Site feasibility and energy assessments for depot charging.
Charger procurement and installation across AC and DC hardware.
Fully Managed maintenance plans to keep chargers running once installed.
Support identifying and applying for available EV charging grants.
Complementary energy solutions, including solar PV and battery storage, for depots looking to reduce grid reliance.
If you’re planning fleet charging infrastructure and want to understand where V2G might fit, our Fleet EV Charging Solutions page is the place to start.
Sources
FAQ
Is V2G legal to use with fleet vehicles?
There’s no blanket ban on V2G, and UK government innovation programmes have actively funded V2X trials rather than restricted them. Specific grid connection and market participation rules still apply, so check requirements with your distribution network operator before deployment.
Which vehicles are currently V2G capable?
The list of V2G-capable vehicles is narrower than the list of EVs generally, since it depends on both the vehicle’s onboard hardware and charger compatibility. Check current compatibility with your charger supplier before assuming any specific model will work, as this list changes as manufacturers add support.
How much does a V2G charger cost?
Published project reporting from Project Sciurus shows single-phase V2G charger costs have fallen from an early figure near £15,000 including installation to a more recent premium in the region of £4,000 to £6,000. Costs vary by site complexity, so a site survey gives a more precise figure for your depot.
What is the main risk with fleet V2G projects?
Interoperability is usually the biggest risk, since chargers and vehicles that lack support for the ISO 15118-20 standard, or a firmware upgrade path to it, can leave a fleet locked out of certain aggregator platforms. Battery degradation and aggregator contract terms are the other main factors to weigh before committing.
Should a fleet optimise site energy before pursuing V2G revenue?
Getting depot energy use right first, through load management and possibly solar PV or battery storage, tends to make a V2G pilot more financially sound. It also reduces reliance on grid revenue that can fluctuate with ancillary service prices.
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