How to share your EV charging infrastructure: A view from the pioneers

In 2022, First Bus took a bold step at our electrified Glasgow Caledonia depot. We opened our in-depot rapid chargers to DPD drivers. At the time, we didn’t realise it, but we were stepping into a new role: a third-party charge point operator (CPO). Not your typical CPO though. Our chargers live inside private bus depots and are primarily designed for overnight charging of our own fleet.

Since then, we've scaled this model across more than ten electrified depots nationwide, powering not just buses, but coaches, trucks, logistics fleets, utility vehicles, and even blue light services. We also took the leap into fully public charging at our former Summercourt depot in Cornwall in 2024. And in 2025, we evolved the concept again by opening a part of our Caledonia depot to public charging during the day.

Along with decarbonising at pace ourselves (1400+ ZEVs on the road already), our vision is to support the electrification of businesses and local communities across the country as well. And all our efforts in the third party charging space come under the banner of our not-very-imaginative-but-quite-effective sub-brand, ‘First Charge’.

Our efforts have been pioneering, and we’ve learned a great deal along the way. In particular, as depot-based eHGV charging begins to scale across the UK, more operators are asking the same question: how can charging assets be shared intelligently? This article sets out the frameworks and practical lessons we’ve uncovered, in the hope they help others move faster, and with fewer surprises.

The three models

At First Bus, we’ve tried and tested three distinct models for shared infrastructure.

Inside the fence: The most intuitive and default model: chargers are located within a private facility and made available to selected third parties, by prior arrangement, during hours when they’re not required by the primary user.

Outside the fence: Chargers sit outside sensitive private premises and are accessible to the public but still benefit from shared (and expensive) grid connections, transformers, and distribution equipment originally installed for the primary user.

Flex the fence: The chargers transition between private and public use at different times of day, enabled by innovative property design and operational controls.

Others may already be exploring models four and five. I’d genuinely love to hear about them and your own learnings on this journey.

I explore each model below in more detail, with particular focus on the traditional inside-the-fence approach, and how it stacks up against conventional public rapid charging from an end-customer perspective.

Inside the Fence

You’ve just installed 20 shiny new rapid chargers at your depot. You’ve paid for the power upgrade. The transformers. The whole lot. But your own fleet only needs them for a predictable four-hour window each day. Which means the chargers sit idle for most of the time.

You then glance at the extortionate public rapid-charging prices nearby. You do some exciting arithmetic involving charger power, hours, and a modest utilisation assumption. Kaching! The numbers look great. Enough to make your finance business partner or CFO raise an eyebrow. The business case seems to write itself.

So why might it be wise to dial expectations down a notch? And what actually makes this model work well in practice?

Let’s look at this systematically, using public rapid charging as a benchmark and assuming your customers are other organisations rather than the public. This is written from a bus-operator perspective, so details will vary elsewhere. Matters relating to risk assessments, health and safety and the operational interface with depot staff are not covered in detail here, but they are, of course, critical.

Public rapid charging vs. in-depot shared infrastructure

Location Public rapid charging is, by design, located at high-traffic hotspots: motorways, retail parks, service areas. Depot charging may or may not be a natural destination for drivers.

Customer awareness Public chargers appear on Zapmap, Google Maps, PlugShare, and the like. Private depots generally can’t be advertised in this way.

Contracts Public charging typically requires none. Depot access usually does for safety, insurance, and governance reasons.

Operating hours Public chargers often run late into the night. Depot charging is constrained by business hours and the primary fleet’s needs.

Authentication and access Public chargers support contactless and roaming cards (Paua, AllStar, Electroverse, etc.). Depot chargers are often optimised for home-fleet use and may lack third-party authentication capability, with roaming integration sometimes adding further complexity.

Welfare and facilities Standardised at public locations. Non-standard in depots, though in-house facilities can sometimes be made available.

Billing and invoicing Fleet drivers using public chargers usually settle centrally via a single fuel-card provider. Depot charging can introduce admin overhead: onboarding, invoicing, reconciliation.

So yes, there are frictions. But there are some very real advantages.

What works in your favour

Charging experience Public charging often suffers from queues, poor uptime, derated chargers, and bays that simply aren’t designed for large vehicles. Shared depot infrastructure, by contrast, generally does what it says on the tin. It’s reliable, predictable, private and for bus operators in particular, already designed with large bays and long cables that suit eHGVs far better than most public sites

Price Because infrastructure sharing is a bolt-on use case to the primary need of self-charging, providers do not need to recover the full capex of the charging installation through external pricing. As a result, depot-based charging can - and should - be cheaper than regular public alternatives.

Putting a product and UX hat on, the more friction you can remove from the in-depot vs. public comparison above, the stronger your offer becomes. In our experience, enabling roaming card payments has been a genuine game-changer. It allows fleets to authenticate, identify, and pay in the same way they would at a public charger.

We’ve seen strong uptake of the behind-the-fence model with customers such as Police Scotland, Openreach and Collins Earthworks (pictured at our Leicester depot below), and we’ve also pioneered integrations with roaming providers like Paua and Allstar to make charging with us as seamless as possible.

Outside the Fence

Perhaps letting third parties onto your site feels like a step too far for now, but you still want a lower-friction way to share infrastructure. That’s where the outside-the-fence model comes in.

If you’re fortunate with land and location (say, a depot near a tourist hotspot), you might install chargers just outside your secure boundary, on the perimeter or in a less sensitive parking area. These chargers can then be opened to both fleets and the general public, published on all the usual maps, and used without contracts.

We did exactly this at our Summercourt depot in Cornwall (pictured below), installing eight rapid charging outlets in the depot car park and opening them to the public from spring 2024 until the depot’s closure in February 2026.

We learned a lot.

Unlike the inside-the-fence model, this is still a standalone capex investment that relies on sensible utilisation forecasts. However, because the heavy electrical infrastructure was shared with the main depot, only the end-chargers themselves were incremental. This made it a far more attractive proposition than a greenfield public CPO site.

That said, brand and familiarity matter. While customer feedback on Zapmap was very positive in terms of charging experience, first-time users were understandably wary of the novelty of charging at a bus depot. (At first, I thought the location in the map might be wrong.. but it’s attached to a bus depot) Perception still counts for much when folks are considering their charging options.

One final note: opening chargers to the general public likely brings you within scope of UK Public Charge Point Regulations (PCPR). Choosing the right technical partners early can significantly reduce the compliance burden.

Flex the fence

The flex-the-fence model is in effect the “have your cake and eat it too” approach. It’s best explained by example.

Our Glasgow Caledonia depot has over 160 rapid charging outlets and is one of the largest rapid-charging hubs in the UK. Since 2022, we’ve welcomed commercial fleets under the inside-the-fence model. But in 2025, we took it a step further.

During the day, when buses are out in service, we temporarily segregate part of the depot and open up 34 ultra-rapid charging outlets to both the general public and commercial fleets between 9am and 4:30 pm.

As can be seen below, the depot also happens to sit near retail amenities, which allows us to offer something that feels no different or even better than a premium public charging hub experience.

Many of the frictions of the traditional inside-the-fence model fall away here. The site can be listed on charger maps with defined opening hours. The hardware/software tech stack supports both public and fleet charging. And customers can access the site with minimal hassle. Additional capex is minimal, though investing in on-site “charging hosts” can further improve customer experience and help mitigate any health and safety concerns.

Bear in mind that as with the ‘outside the fence’ model, this model also may fall under the PCPR regs.

So which model is best?

There’s no universal answer. But if the property layout allows it, either through retrofit or upfront design, it’s hard to beat having your cake and eating it too by flexing the fence.

That said, the simplicity of the classic inside-the-fence model shouldn’t be underestimated. For long-standing customers willing to commit to guaranteed volumes in exchange for preferential pricing, it’s a perfect match. Particularly where the site’s unique strengths (privacy, large bays, high availability) closely match their needs.

And finally, beyond models and economics, there are softer ingredients that really make this work, especially when we’re pioneering without a rulebook. Curious and innovative customers, willing to experiment with us. Patient and open-minded depot managers juggling an already demanding day job, but very aware of the wider business and industry benefits of letting third parties use their chargers. Senior leaders willing to take measured risks and let their teams explore non-core activities. And, of course, a committed project team that genuinely gets a buzz every time under-utilised infrastructure gets put to good use.

That’s been our experience, and we’re only just getting started.