About Inverter Generators
Unlike conventional generators that produce raw AC power, inverter generators convert AC to DC and back to a clean sine wave. The result is total harmonic distortion (THD) typically below 3% — well within safe limits for modern electronics.
Most quality UK inverter generators run between 50–60 dB at quarter load, roughly the volume of a normal conversation. Look for eco-throttle or smart-throttle modes that adjust engine speed based on demand to save fuel and reduce noise.
Parallel capability lets you link two inverter generators together to double your power output — useful for running an air conditioner or larger appliance at a campsite or worksite.
Sizing is where most buyers go wrong. Work from the appliances you actually need rather than the size of the property: a fridge-freezer, boiler, router and lighting comes to roughly 1.5–2.5kW of continuous load. Then check starting watts — motors in fridges, pumps and boilers briefly draw two to three times their running figure, and an undersized generator will trip every time the compressor kicks in.
Runtime figures are quoted at 25% or 50% load, not full output. A 2kW inverter running a fridge and a few lights will comfortably beat its headline hours; the same machine near its ceiling will not. For overnight backup, look for at least eight hours at half load and check the actual tank capacity rather than trusting the marketing figure.
Dual fuel inverter generators run on petrol or LPG. Bottled gas stores indefinitely, which is a real advantage for a machine that may sit unused for two years between power cuts — petrol left in a tank goes stale within months and gums up the carburettor. If the generator is bought purely for emergencies, dual fuel is worth the premium.
Never plug a generator into a wall socket to feed the house. Backfeeding is illegal in the UK and puts lethal voltage onto the network for anyone working on the line. Either run appliances directly from the generator on heavy-duty leads, or have a qualified electrician fit a manual changeover switch. Always run the generator outdoors, well away from doors, windows and air bricks — carbon monoxide from generators kills people in the UK every year.
Maintenance is minimal but not optional. Change the oil after the first five hours and annually thereafter, keep the air filter clean, and either drain the fuel or add a stabiliser before winter storage. Run the machine under load for half an hour twice a year so you find out it works before you actually need it.