A logistics depot adding twenty 50 kW chargers has added a megawatt of potential demand to a site that previously drew 300 kW. That is the problem to solve, and solar addresses only part of it.
Commercial fleets typically charge overnight, when vehicles are back at the depot and electricity is cheapest. Solar generates during the day, when vehicles are out.
So the direct match is poor. Solar can supply chargers during the day for vehicles that happen to be present, and it reduces overall site consumption, but the notion of vehicles running on the depot's solar is mostly not what happens without storage.
Where the match is genuinely good: sites with vehicles that return through the day, opportunity charging during loading, shift patterns keeping some vehicles onsite during daylight, or customer vehicle charging at retail and hospitality sites.
Before anything else, establish your existing connection capacity and how much headroom exists. Adding charging load frequently exceeds it, and a connection upgrade can be expensive and slow – in constrained networks, years.
This is where storage earns its place. A battery lets you charge vehicles at a rate exceeding your connection capacity by supplying the difference from stored energy, recharged during periods of low site demand.
A site with a 400 kW connection can support a charging peak well above that, provided the energy is available and the timing works. Compared to a connection upgrade, storage is frequently faster, cheaper and more flexible.
The cheapest capacity is the capacity you do not need.
Most fleet vehicles sit at a depot far longer than charging requires. A van needing four hours of charge parked for fourteen has ten hours of flexibility. Sequencing across that window, rather than starting everything simultaneously, dramatically reduces peak demand.
Load management systems that allocate available capacity dynamically across chargers – prioritising by departure time and state of charge – routinely allow far more chargers on a given connection than static allocation.
Do this before sizing storage. Storage sized against an unmanaged charging peak is storage sized against a problem you did not need to have.
A workable architecture for a depot:
Charging creates exactly the kind of sharp, high peak that demand charges punish. A site that was previously flat can find its demand charge multiplying.
Model this specifically. In some tariffs the demand cost of charging exceeds the energy cost, which changes the entire economic case and makes both smart charging and storage more valuable than an energy-only analysis suggests.
Fleet electrification is usually phased. The mistake is designing infrastructure for phase one and discovering phase two requires starting again.
Even if you are installing six chargers now, size the cabling, containment and switchgear for the eventual fleet. Trenching and cable routes are the expensive, disruptive parts – installing spare capacity during the first dig costs a fraction of returning later.
The chargers themselves can be added incrementally. The infrastructure underneath them should not have to be.