Building the business case your finance team will believe

Depot electrification lives or dies on one number: the total cost of ownership compared with carrying on with diesel. Get the sticker price of chargers and vehicles and it looks expensive; build a proper TCO across the life of the assets and the picture usually flips. The job of this guide is to help you build a case your finance director will actually sign off, because a business case that ignores half the costs — on either side — gets picked apart in the first meeting.

Count the whole cost, on both sides

A fair comparison puts the full lifetime cost of the electric option against the full lifetime cost of the diesel one — not just the purchase prices. On the electric side that’s vehicles, chargers, installation and grid works, energy, and maintenance. On the diesel side it’s vehicles, fuel, maintenance, and the rising costs of running combustion fleets. It’s the comparison that matters, and diesel’s ongoing costs are easy to underestimate.

Where electric wins: the running costs

The upfront cost of electrifying is higher; the running cost is lower. Electricity per mile typically undercuts diesel per mile, electric drivetrains need less maintenance, and there’s no exposure to volatile fuel prices. Over a vehicle’s life those annual savings accumulate into the number that carries the case. This is why the tariff and charging strategy matter so much — they set the size of the win.

Where the upfront cost lands: capex and grants

The counterweight is the capital cost, and this is where funding changes the maths. A grant that covers a share of chargepoint and civil costs directly reduces the upfront figure and shortens the payback. Factoring available funding into the business case — realistically, and timed to an application window — can be the difference between a marginal case and a clear one.

Payback and total cost of ownership

Two figures land the decision. Payback period answers “how long until the running-cost savings repay the extra upfront cost?” Total cost of ownership answers “over the whole life of the assets, which option costs less overall?” Present both. Payback speaks to cash flow; TCO speaks to the long-run decision. A strong case usually shows a payback within the asset life and a lower TCO than staying diesel.

Make the assumptions visible

The fastest way to lose a finance audience is a black-box spreadsheet. Show your workings: the electricity price you assumed, the annual mileage, the maintenance saving, the grant you expect, the vehicle life. Sensible, stated assumptions build trust — and let the reader stress-test the case rather than distrust it. An honest case with visible assumptions beats an optimistic one that can’t be interrogated.

The bottom line

The business case is rarely won on the purchase price and rarely lost on the running cost. Build the full TCO across the asset life, put realistic funding into the capital side, present payback and TCO together, and show every assumption. Done properly, the number usually makes the argument for you.