Most conversations about HGV charging economics start and end with the pence-per-kWh markup. Charge trucks, sell the electricity for more than it cost, repeat. In a UK market with volatile wholesale prices and grid connections that take months to secure and hundreds of thousands of pounds to build, that leaves most of the money on the table. A depot's meter has four separate ways to earn, and only one of them is selling kWh to a driver.
We covered the mechanics of the fourth of those, which UK electricity markets a site can register for, in an earlier piece. This one is narrower and more concrete: what the four layers actually look like on an HGV depot's numbers, and what a real 25MW trial found when we tested how much they're worth.
The Same Meter, Four Ways to Make Money
Buying power smarter, generating and storing some of it on site, pricing what you sell dynamically, and getting paid to flex your load, none of these require selling a single extra kWh to get more out of a site that's already built. They stack on top of each other, and the further down the list you go, the more sophisticated the platform behind the site needs to be.
Layer One: Buying Power Smarter (the Foundation)
Say a depot charges 10,000 kWh a day, bought at a flat £0.15 per kWh. That's £1,500 a day in energy costs. Load forecasting and electricity price forecasting can identify which 30% of that volume can safely shift into low-price overnight windows, typically around £0.10 per kWh, without disrupting the fleet's turnaround schedule. That shift alone saves roughly £500 a day, close to £15,000 a month.
No extra electricity sold. No pricing change for drivers. Purely the difference between buying on a flat rate and buying against a forecast. The bigger the site, the bigger this number gets, and it's the layer every depot should have in place before touching the other three.
Layer Two: Solar and Storage as a Buffer
On-site solar generation and battery storage sit on top of procurement optimisation, not instead of it. Storage acts as an energy reservoir: it absorbs cheap or self-generated power when it's available and releases it later, smoothing out the savings procurement optimisation already found and giving the site a dispatchable asset it can use in the next two layers. For the hardware payback math on solar and storage specifically, see our depot solar and storage model and the BESS versus grid-only comparison.
Layer Three: Dynamic Pricing (the Core Lever)
This is the layer drivers actually see. When wholesale prices are low, dynamic pricing pulls more vehicles onto site to charge. When prices spike, pricing up protects margin and nudges demand away from the peak, without simply refusing service. Done well, this adds real percentage points of margin on the same traffic a site would have had anyway, while helping flatten the peaks the grid is straining under.
Layer Four: Flexibility Revenue (the Upside)
Aggregate a site's load, and any storage or V2G-capable vehicles on it, into a single dispatchable resource and it can be offered into demand response and balancing markets. The grid pays for the flexibility a site is willing to provide. We've written in detail about which specific UK markets are live for this today, wholesale arbitrage, NESO frequency response, the Capacity Market and V2G export, and what each requires, in The Fourth Decision. This piece is about what all four layers are worth together, not the mechanics of any one of them.
A depot like this isn't just charging infrastructure. Every cabinet, panel and battery on site is a potential trading asset.
The Trial: 25MW of Aggregated Capacity
We tested how much these layers are worth against 25MW of aggregated capacity, in three stages, each building on the last.
Day-ahead joint optimisation planned procurement and dispatch across the full 25MW portfolio a day in advance, and lifted daily profit by approximately 6.2% against a baseline without that planning. A 4-day live run on a real operating site took that same approach out of simulation and into production, where operational constraints are messier and forecasts are never perfect, and still delivered a 9.88% uplift in total profit over the period. Real-time rolling dispatch went further again, re-optimising continuously as prices, load and generation shifted intraday rather than committing to a plan and holding it, adding a further 9.0% on top.
The pattern that matters: the uplift didn't come from a bigger model alone. It came from a model accurate enough to trust, paired with execution on site reliable enough to act on what the model says, in real time, without a human in the loop. Either one without the other leaves money on the table.
Four Capabilities That Separate a Platform From a Pretender
When you're building a depot or choosing a platform to run it, four capabilities determine whether any of the above is actually achievable, or just a slide in a sales deck.
| Capability | What it means | What it enables |
|---|---|---|
| Aggregation | Pooling a site and nearby load into one dispatchable resource | Scale large enough to matter to a market operator |
| Forecasting | Load forecasting, spot price forecasting, spread direction | Knowing when to buy, store, sell or hold |
| Control | Dynamic pricing, load shifting, V2G where applicable | Actually acting on what the forecast says |
| Market access | Trading on the operator's behalf: bids, capability declarations, settlement | Getting paid for the flexibility offered |
The first three determine whether a site can flex. The fourth determines whether it gets paid for it. Without market access, a well-forecast, well-controlled, perfectly aggregated site is still just a load as far as the electricity market is concerned, not a participant in it.
Stop Optimising for the Spark Spread Alone
A UK grid connection for a depot of any size typically takes somewhere between 18 and 36 months to secure and can cost anywhere from £50,000 to £500,000 or more, depending on the capacity required and the state of the local network. Once that connection exists, the question isn't whether it can be used more intelligently, it's how much profit is being left unclaimed by treating it as a pipe for selling electricity rather than a platform for trading it.
The next generation of UK charging operators isn't just installing equipment or brokering electrons between the grid and a driver's battery. It's operating a portfolio of energy assets inside the power market, the same connection, the same hardware, doing more than one job.
See What Your Depot's Load Is Worth
Send us your site's daily volume and connection size and our engineering team will model what these four layers look like for it, using the same methodology behind the 25MW trial above.
Talk to the engineering teamFrequently Asked Questions
How do HGV charging depots actually make money beyond selling electricity?
Four layers stack on top of drive-up charging revenue: buying wholesale power at optimised times instead of a flat rate, using on-site solar and battery storage as a cost buffer, dynamic pricing that shifts vehicle demand toward cheap periods, and flexibility revenue from offering aggregated depot load into demand response and balancing markets.
How much can energy procurement optimisation save an HGV depot?
On a site using 10,000 kWh a day at a flat £0.15 per kWh, that's £1,500 a day in energy costs. Shifting 30% of that volume into low-price windows around £0.10 per kWh using load and price forecasting saves roughly £500 a day, close to £15,000 a month, without selling a single extra kWh.
What did the 25MW trial actually measure?
Three optimisation stages were tested against aggregated capacity of 25MW: day-ahead joint optimisation across the portfolio, which lifted daily profit by approximately 6.2%; a 4-day live run on a real operating site, which lifted total profit by approximately 9.88%; and real-time rolling dispatch that re-optimises as conditions shift intraday, which added a further 9.0% uplift.
What should an operator look for when choosing an energy trading platform for a charging depot?
Four capabilities: aggregation, the ability to pool a site and nearby load into one dispatchable resource; forecasting, covering load, spot prices and spread direction; control, to actually drive dynamic pricing, load shifting and V2G where applicable; and market access, the ability to trade on the operator's behalf, including capability declarations, performance verification and settlement. The first three determine whether a site can flex. The fourth determines whether it gets paid for it.
Grid EMS Day-Ahead Optimisation Real-Time Dispatch Dynamic Pricing