Generator Backup and Power Cuts: What to Budget for an Outdoor Event

The power goes at the wrong moment and your outdoor event goes dark and silent with a few hundred people standing in it. That is the risk you are budgeting against, and it is worth doing the arithmetic properly rather than accepting whatever the vendor suggests.

The short answer: add up the load of everything that must keep running, add a margin on top, hire a generator rated above that total, and budget fuel by asking the supplier for consumption in litres per hour and multiplying by the diesel price on the day. Then place the machine far enough from the stage that nobody hears it, and check in writing whether the venue's own backup covers your equipment or only its own lights.

Work out the load before you ask for a quote

Ask each vendor for the power draw of their equipment in watts or kilowatts, and put it on the same table you compare their quotes on. Sound, lighting and video are the big three. Then add the things people forget.

• Sound: amplifiers, mixer, monitors
• Lighting: stage fixtures, general wash, any moving heads
• Projector, screen and the laptop running it
• Registration desk: printer, laptop, phone charging
• Catering: warmers, hot water, any refrigeration, sized against the headcount you are feeding
• Fans or coolers for the crowd
• Ambient and pathway lighting, and the toilets
• Anything the venue runs off the same supply

Total it up, then add a margin. Some equipment draws considerably more at the moment it starts than it does while running, and lighting rigs get added late in the planning. A generator running near its limit all evening is a generator that trips.

Give that total to the hire company and let them recommend a rating. Ask them to state the recommended size in writing against your load figure, so the responsibility is shared.

Fuel cost, without guessing

Do not accept a rough number for fuel. Ask two questions.

• What is the consumption in litres per hour at roughly the load I described?
• Is fuel included in the quote, or billed separately at cost?

Multiply consumption by the number of hours the machine will actually run, and remember that includes setup, sound check and dismantle rather than only the programme. Then multiply by the diesel price at the time, which changes, so check it near the date rather than budgeting on an old figure. Add a margin for the machine idling between segments.

Also ask who fills it and who is responsible if it runs dry mid programme. The answer should be a named person from the hire company on site, not your volunteer.

Placement and noise

A generator at the back of the stage will be in every video you take. Placement is a real design decision.

• Put it downwind and behind a solid structure if there is one, as far from the stage and the audience as the cable run allows.
• Ask the vendor about a canopy or silenced unit. Quieter machines cost more and are usually worth it for anything with speeches.
• Keep the exhaust pointing away from people, seating and food service. Fumes matter more than noise.
• Fence it off or keep a person near it, with a sign in both languages. Curious children and hot machinery do not mix.
• Check the cable route. Cables across a walkway need matting or covering, and cables in the open need protection from rain.

Longer cable runs cost money and lose some power, so discuss the distance with the vendor rather than deciding it on the day.

What the venue's backup actually covers

This is the question that catches people out. Many venues have backup that powers house lighting, fans and the office, and nothing else. Your sound rig plugged into a socket may not be on that circuit at all.

Ask the venue, in writing:

• Does the backup cover the sockets I will be using, or only the house lighting?
• What is the capacity, and what is already on it?
• How long does the changeover take, and does equipment need to be restarted?
• Who operates it, and will that person be present for the whole event?

If the changeover takes several seconds, your sound will cut out and your audio equipment may need to be brought back up manually. For anything with a live audience, that is worth planning around.

A small backup for the things that must never fail

Even with a generator, keep an uninterruptible supply or a battery pack for the mixer and the laptop running your presentation. Losing the crowd lighting for ten seconds is survivable. Losing the file that the whole programme depends on is not.

Budget lines to write down

• Generator hire for the full period, including setup and dismantle
• Fuel, calculated from litres per hour and the current diesel price
• Cable, distribution boards and matting
• Operator on site for the whole event
• A silenced unit or canopy, if noise matters
• A small battery backup for critical equipment

Get all of it on one quote, ask what is excluded, and confirm the arrival time. A generator that turns up an hour before the programme has not been tested.