What we cover

Application	Typical requirement
Container and modular offices	Lighting, heating, computers, kettle and microwave. Small load, long hours, and noise matters because people are sitting next to it.
Welfare units	Hot water, drying room, canteen. Peaky load with big morning and lunchtime spikes — the classic case for battery buffering rather than a bigger engine.
Remote work sites	Tools, compressors, pumps. High starting currents that size the system, and often a long distance from anything.
Temporary compounds	Security, cameras, gates, site cabins. Runs continuously at low load — the worst possible duty for a diesel on its own.
Mobile and event units	Needs to travel, set up quickly, and be quiet enough to sit near the public.

Why hybrid usually wins on site

Temporary sites have a characteristic load shape: a long, low base load overnight and through quiet periods, with short heavy peaks. A single diesel sized for the peak spends most of its life at a fraction of its rating.

That costs you three ways. Fuel burnt for nothing. Engine hours accumulating towards services and wear. And wet stacking — unburnt fuel in the exhaust that eventually needs an engine strip to put right.

What a battery does to that

The battery covers the base load with no engine running at all. The generator starts when the battery needs charging or when a real peak arrives, runs at high load where it is efficient, and shuts down. On a typical welfare or security compound that can take engine hours down by two thirds.

The knock-on effects matter as much as the fuel: fewer refuelling visits, fewer services, and overnight silence on sites with neighbours.

Connection cost versus generation

For anything semi-permanent, it is worth asking the question properly rather than assuming. A DNO connection has a cost, a lead time, and a standing charge. Generation has a capital cost and a running cost.

The crossover depends on how long the site will be there, how far the connection point is, and how much you will actually use. We can run both cases for you — and if a connection is genuinely the better answer we will say so. We handle grid connection applications too, so we have no reason to push you one way.

Practical things that decide the design

Noise limits. Residential neighbours, night working, or a planning condition will often rule out an engine running overnight — which makes battery capacity a requirement rather than an option.
Fuel logistics. How often can a bowser reach you, and what does each visit cost? That usually justifies more battery.
Security. Fuel and batteries both walk. Containerised, alarmed installations exist for a reason.
Redeployment. If the kit moves to the next site, it needs to be built to be moved, not built in place.
Emissions requirements. Increasingly written into contracts, particularly on public sector and urban work.

Hire, buy, or build

For short projects, hire usually makes sense. For anything running more than a year, or for a company that will keep needing it, owning a properly specified hybrid unit normally pays back inside the second deployment — the savings follow the kit from site to site.

We build custom hybrid units for exactly this. See custom hybrid builds.

Power where there is no supply.