For many businesses the generator has quietly become the main power station, and diesel one of the biggest running costs. Understanding what drives that bill is the first step to reducing it.
Fuel use follows load, not generator size
A generator burns fuel according to how much power it delivers, and it is least efficient at light load. An oversized generator on a small load burns more fuel for each unit of electricity. Diesel engines that run lightly for long periods also suffer carbon build-up and need more maintenance.
Hours multiply everything
Fuel per hour times running hours times the diesel price gives the core of the bill. Long outages, generators left running when the grid is back, and evening or weekend running all add hours that are easy to overlook.
The costs beyond fuel
- Oil, filters and servicing, which scale with running hours.
- Repairs and the shorter life of engines that run constantly.
- Fuel logistics, storage and the risk of losses.
- Production lost during switch-overs and breakdowns.
What solar and storage change
Solar can carry daytime load directly, so the generator runs less during the hours when most businesses use the most power. Batteries cover outages and smooth switch-overs, and can let the generator run only when it is efficiently loaded. The generator becomes a backup instead of the main source.
How much this saves depends on your daytime load, roof or land space, and how your outages fall. That is why a proper assessment measures your load before recommending a system size.
Get a rough figure for your own site with our diesel calculator, then ask us to measure the real one.