This article focuses on problem diagnosis. If you have already identified the Power Island bottleneck and want to see the ROI calculation for a specific solution, you can skip directly to “How to Eliminate the Power Island Problem: Increase Charging Throughput & Unlock £36,500 Annual Savings”

I get this call a lot, usually from someone who’s been managing a depot for a year or two and just can’t figure out why the numbers don’t add up. They’ve got a decent grid connection, they bought from a reputable supplier, the install went fine — and yet at 6am there are still two or three vehicles sitting at 60%, and the dispatcher is not happy.

The first question I always ask is: how many power cabinets do you have, and are they talking to each other?

Most of the time the answer is no. And that’s the whole problem right there.

What’s actually happening in your depot at night

Picture a fairly typical setup. Four power cabinets, each rated 480kW, each feeding three dispensers. A mixed fleet — couple of HGVs, a handful of vans, maybe some passenger EVs in the mix too.

Around 8pm everything starts rolling in. The vans plug in first because they finish their routes earlier. By 11pm most of them are sitting near 80%, drawing maybe 30-40kW each — barely sipping power at that point, that’s just how lithium charging curves work, nothing wrong with the battery. Meanwhile your HGV comes back at midnight at 15% SOC and needs to be back out the door by 5am. It needs every kilowatt it can get.

Here’s the bit that catches people out: in a conventional setup, the power sitting unused in those van cabinets cannot get to the HGV. It’s locked. The cabinet doesn’t know or care that there’s a starving vehicle three bays over — it just keeps doing what it was told to do at install. So you’ve got, what, a couple hundred kilowatts of capacity just… sitting there. Not being sold, not being used, not doing anything except making your grid connection look bigger on paper than it actually is in practice.

I did the maths on this for someone last year. A 2MW site running at this kind of inefficiency was leaving roughly £100 a day on the table — between the trapped idle power and a knock-on efficiency loss I’ll get into in a second. That’s £36,500 a year. For one site. If you’ve got three or four depots, you can see where this is going.

It’s not just about wasted power, it’s about wasted efficiency too

This is the part most fleet managers haven’t been told, and honestly I don’t think it’s because anyone’s hiding it from them — it’s just not something that comes up unless you go looking for it.

Every power module has what I’d call a sweet spot. Manufacturers love quoting 97-98% efficiency on a spec sheet, and that’s not technically a lie, but it’s measured at one specific load point — usually somewhere around 60-80% of the module’s rated capacity. Push that same module to 100% and the efficiency actually drops. More heat, more loss, control loop gets sloppier. It’s just how power electronics behave.

So if your cabinets are running unevenly — some modules maxed out serving the hungry HGV, others nearly idle serving the topped-up vans — none of them are sitting in that efficient zone. You’re paying for electricity that’s quite literally turning into heat instead of going into a battery.

What HanYuan actually changes

This is the bit I find genuinely satisfying to explain, because it’s not a software patch or a clever app — it’s the hardware architecture itself.

HanYuan treats every power module across every cabinet on site as one shared pool. There’s no “Cabinet A’s power” and “Cabinet B’s power” — there’s just available capacity, and an algorithm constantly redirecting it to wherever it’s needed most. When the vans taper off near 80%, that freed-up capacity doesn’t sit idle. It moves, automatically, to the HGV that’s starving for it. No one has to log into a dashboard and manually rebalance anything.

Same architecture also fixes the efficiency problem, almost as a side effect. Because the system spreads load across more modules rather than letting a few run flat out while others coast, it keeps modules sitting in that 60-80% efficiency zone far more consistently. We typically see that translate into a 1-1.5% bump in overall conversion efficiency. Doesn’t sound like much until you’re running thousands of kWh a day through the site — then it’s real money, every single day, compounding.

Practically, a single HanYuan system scales from 480kW up to 1,920kW just by adding cabinets into the same pool — so if your fleet grows, you’re not ripping out infrastructure, you’re just expanding the network it already belongs to.

What I’d actually check if I were you

If you manage a depot and you’re not sure whether you’re sitting on this problem, here’s the honest test: look at your busiest return window — usually late evening through early morning — and check whether any cabinet is sitting well above 80% load while another is sitting well below it at the same moment. If you see that pattern, you’re losing money right now, tonight, and probably have been for a while.

It’s not a failure of planning. Most depots were built before anyone really thought through what happens when twenty vehicles with twenty different charge states all show up within the same three-hour window. The fix isn’t to add more capacity — it’s to stop the capacity you already have from sitting in silos.

If you want to talk through your specific setup, happy to have that conversation. Bring your cabinet layout and your typical return schedule and I can usually tell you within a few minutes whether this is costing you money.