Generator vs portable power station for site work — which earns its keep in 2026

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Right. About 18 months ago we'd have told you a portable power station was a glorified phone charger and to stick with a 2kW Honda generator. Things have moved on. EcoFlow's Delta 2 Max and Bluetti's AC180 now genuinely run a circular saw for a working day without needing a top-up. But they're still wrong for some jobs and we keep seeing trades buy the wrong one for their actual usage. Here's how we'd think about it.

What each one actually is

A traditional generator is a petrol or diesel internal combustion engine driving an alternator. You pour in fuel, you pull a cord (or push a button), it makes AC mains-equivalent power. Most working-trade units are 2-3kW continuous output with a 4-5kW peak.

A portable power station is a lithium battery pack with a built-in inverter to deliver AC output, plus DC and USB outputs. You charge it from mains, a car, or solar. Quiet, no fumes, but limited to whatever's in the battery.

Same job — different physics. The trade-off is fuel weight vs battery weight, plus emissions vs charge time.

The capacity comparison that actually matters

A 2kW Honda EU22i generator weighs 21kg, holds 3.6 litres of petrol, and runs about 8 hours at 25% load (so call it 4 hours under typical trade load). It'll restart from a half-empty tank for £6 of fuel from any garage.

An EcoFlow Delta 2 Max weighs 23kg, has 2,048Wh capacity, peak output 2,400W with X-Boost. That's roughly 4 hours running a 500W circular saw at moderate use, or 6-7 hours running a 250W angle grinder, or a full day powering a couple of LED site lights and a battery charger.

Read that again. Same weight, roughly comparable runtime — but the petrol box can be refuelled in 90 seconds and the battery box takes 90-120 minutes to recharge from mains, or longer from solar.

Where the power station wins

The cases where we'd genuinely rather have a lithium unit:

Indoor work

Petrol generators can't run indoors. Carbon monoxide kills, and it kills fast. There were 47 reported CO deaths from petrol generators in the UK in 2024 according to RoSPA, mostly indoor or enclosed-garage use. So if you're a kitchen fitter, a plumber doing a boiler install in a basement, or a sparky working in a converted warehouse without temporary power — the lithium unit is the only safe option.

Plus they're silent. Working in occupied buildings — schools during term time, hotels, hospitals — the noise alone rules out a petrol generator before you even get to the emissions.

Low-power tools, long sessions

Site lighting, battery chargers, soldering irons, laptops, monitor for plan review, phone charging, a low-wattage hot box for adhesive cure. All under 300W. A 2kWh power station easily covers a 10-hour day of that and you charge it overnight at home.

A petrol generator running at 5% of its capacity all day is wasteful and the engine wears out faster from carbon build-up. Power station is better here.

Conservation areas and noise restrictions

If you work in places where there's a 7am noise rule, or an LEZ/ULEZ zone, or a residents' association that complains about generator noise — lithium wins by default. London ULEZ doesn't currently restrict petrol generators directly but several London boroughs have local noise enforcement that does.

Light grid extension

You've got mains at the front of the property and need to power a saw at the back of the garden 40m away. A lithium unit you carry. A petrol generator you drag, and once you've got 40m of extension cable the voltage drop on a high-draw tool starts costing you motor life.

Where the petrol generator still wins, easily

High-draw, continuous power tools

A 2kW circular saw running flat out for an hour. A 1.5kW SDS hammer drill on a brick wall for an afternoon. A 2.2kW pressure washer running off-grid. Anything that pulls genuine sustained kilowatts.

Run a 2kW saw off a 2kWh power station and you've got 50 minutes before it's flat. Run it off a 2kW Honda EU22i and you keep going until you run out of petrol or arms.

Multi-day off-grid work

Site cabin power, multi-day camping site fit-out, no mains within sensible cable reach. Petrol generator wins because you can carry 20 litres of fuel in a jerry can. You can't carry 20kWh of battery in any sensible form.

Welding, plasma cutting, MIG/TIG work

Welder draws are spiky and high — 4-6kW peaks even on low-amp small welders. Most portable power stations protect themselves against this and shut down. Some inverter generators handle it too, but if welding is regular you want a dedicated 5kW+ generator with surge handling.

Cold weather

Lithium batteries lose 30-50% of usable capacity below 0°C. A petrol engine starts fine in any UK winter as long as it has clean fuel and a working spark plug. For winter site work, the petrol box is more reliable.

What we'd actually buy

Three scenarios, three answers.

Self-employed kitchen fitter / plumber doing residential indoor work. EcoFlow Delta 2 Max (2048Wh) or Bluetti AC200L (2048Wh, slightly cheaper). £950-£1,200 typical price. Pays back in saved fuel and trips to the garage within 18 months on top of safer indoor operation.

External roofer / cladder / scaffolder. Honda EU22i (2.2kW) at around £1,300 brand new, or a Hyundai HY3500SEi (3.3kW) at around £750-£850. The Honda is quieter and lighter, the Hyundai is more powerful and cheaper. Both run for years with basic maintenance.

Two-van fit-out firm with mixed work. Both. One Delta 2 Max for indoor and quiet work, one 2-3kW petrol inverter generator for outdoor and high-draw days. Total kit £1,800-£2,200. Covers every realistic situation.

The maintenance question nobody talks about

Petrol generators need work. Fresh fuel every 6 months (or use a stabiliser), oil change every 50-100 hours of run time, spark plug yearly, air filter cleaned regularly. Running stale fuel through a small generator is the single biggest cause of write-offs — carburettors gum up and replacing them costs £80-£150 a pop. Buy a 25ml bottle of fuel stabiliser. Use it.

Lithium power stations need almost nothing. Keep them between 20% and 80% if you can — full cycle every couple of months to balance the cells. Don't store at 0% for long periods. Cycle life is typically 3,000 cycles to 80% capacity, which is roughly 8-12 years of working trade use.

The total cost over five years

Rough numbers for a working trade doing 3 generator-days per week:

• Petrol generator (Hyundai HY3500SEi): £800 unit + £180/year fuel + £60/year maintenance = £2,000 over 5 years.
• Power station (EcoFlow Delta 2 Max): £1,100 unit + about £30/year electricity to recharge from mains + nothing else = £1,250 over 5 years.

The power station looks cheaper but it's only running a third of the tool load the petrol generator handles. Don't compare them on cost — compare them on what they actually do for your daily work.

Solar — useful or marketing fluff

Most modern power stations accept solar input via XT60 or MC4. A 200W folding panel costs £200-£350. In UK conditions, expect 100-150W in good summer light, 30-60W in winter overcast.

Useful for: multi-day off-grid work where you can leave panels out all day, low-power demand. Pointless for: site work where the unit goes home every night and you've got mains. Mains charging is faster, cheaper, and more reliable.

A note on safety

Even if you've used petrol generators for twenty years, don't run them in a partially enclosed space. 'I've left the door open' is the line we hear from CO poisoning survivors. Open door doesn't mean enough ventilation — CO is heavier than air and pools. If you can smell exhaust at all, the CO level is already too high.

Lithium power stations have their own safety quirks — thermal runaway from impact damage is real, though rare. Don't drop them off a scaffold deck. If a cell starts venting, get it outside fast and let it burn out in a non-combustible area. Water won't put it out.

The bottom line

Power stations are a real category now, not a gimmick — but they're a complement to a petrol generator for most working trades, not a replacement. If your work is mostly indoor or low-power, buy a power station and ditch the generator. If your work is mostly outdoor with high-draw tools, stick with petrol and add a small power station only if it earns its keep on your specific job mix. Most trades who buy both end up using them in a roughly 60/40 split for the year, weighted toward whichever matches their main work.

And whichever you choose — get a CO alarm for your van or workspace anyway. They're £15. The risk profile of working trades around portable power is the highest in any sector.