What to expect
| Typical duration | Portable setup 1 day · fixed standby install 3–7 days · service 2–4 hours |
|---|---|
| Cost band | Figures live in the cost index |
| Permit required | Electrical certification required · fuel storage rules apply |
| Seasonal constraint | Install Oct–Apr · service before June |
Why a cut here is worse than a cut elsewhere
On the mainland losing power for two hours is an inconvenience. Here it stops the water as well, because most properties do not run on mains pressure — they run on a tank and a pump. No electricity, no pump, no water, and on a property with guests that becomes a problem within about twenty minutes.
- Water stops. Booster sets and pressure pumps are electric. A full cistern is no use without them.
- Refrigeration stops. For a hotel or a restaurant that is stock, and the clock starts immediately.
- Pool circulation stops. In August water goes green faster than owners expect.
- Air conditioning stops at the hottest point of the year, in properties full of paying guests.
- Card payments and door locks stop in commercial properties, which is frequently the failure nobody planned for.
None of this argues that everyone needs a generator. It argues that if you are letting property or running anything commercial, the cost of a cut is not the same number the mainland uses.
Sizing, and the mistake everyone makes
The common error is sizing for the running load and forgetting the starting load. Motors — pumps, compressors, air conditioning — draw several times their running current for the moment they start. A generator sized to the nameplate figures will cope beautifully until three things try to start at once, and then it will stall.
The second error is sizing for everything. Very few properties need full backup. A hotel usually needs refrigeration, water, lighting and the systems that let it operate; it does not need every guest air conditioner. Deciding what is on the essential circuit is a design decision worth making deliberately, and it makes the generator dramatically smaller and cheaper.
Changeover, which is not optional
Connecting a generator to a property's wiring without a proper changeover is dangerous, and not only to you. If the generator can push power back onto the utility network it can energise a line that a technician believes is dead.
A correct installation isolates from the grid before it connects the generator — a manual changeover switch at minimum, an automatic transfer switch on anything that matters. It is certified electrical work and it is the part that must not be improvised.
This is electrician territory as much as generator territory, and on this island it is often the same person.
Servicing, which is always skipped
A standby generator spends the year not running. That is the problem: fuel degrades, batteries flatten, coolant leaks quietly, and rodents find the enclosure a pleasant place to spend the winter.
The result is a machine that has not been tested since it was installed and does not start on the night it is needed. Servicing it means running it under actual load, not letting it idle for ten minutes.
- Run under load at least quarterly, and before the season starts.
- Diesel degrades; fuel that has been in the tank since last summer is a genuine cause of failure.
- Batteries are the most common single reason a standby set does not start.
- Air filters clog fast here — volcanic dust again.
- Salt air corrodes external enclosures, so where it lives matters.
What this trade covers
- Sizing surveys, including starting loads and essential-circuit design.
- Portable generator setup for domestic backup.
- Fixed standby installation with manual or automatic changeover.
- Changeover panels and essential-loads distribution boards, certified.
- Fuel storage, tanks and the rules that apply to them.
- Servicing and load-bank testing, quarterly or pre-season.
- Emergency hire and temporary supply for events or during a failure.
Questions people actually ask
Does a villa really need a generator?
Most do not. A let property that would lose a booking to a long cut, or one on a supply that is known to be unreliable, might. A conversation about what a cut actually costs you is the right starting point, not a catalogue.
What size do I need?
Nobody can answer that without a survey, because starting loads matter more than running loads and because the answer changes completely if you define an essential circuit.
Can I just buy one and plug it in?
A portable generator with appliances plugged directly into it, yes. Connecting one to the property wiring requires a proper changeover and certified electrical work.
How often does it need servicing?
Run under load quarterly and serviced before the season. A standby set that has not run since installation is not backup, it is an ornament.
Are solar and batteries an alternative?
Increasingly, for domestic backup, and they need no fuel and no maintenance visit. They are poor at large starting loads, so for pumps and commercial refrigeration a generator is often still the answer. See photovoltaics.