Power is one of those event logistics that nobody notices when it works and everybody notices when it fails. A power cut during a headline performance, a tripped circuit shutting down the bar, or a generator running dry mid-set are all avoidable problems that stem from poor planning.
Whether your event uses mains power, temporary generators, or a combination of both, here is what you need to plan for.
Calculating your power requirements
The first step is understanding how much power your event needs. This means getting power requirements from every supplier and department, then adding them together with a safety margin.
Common power consumers at events include:
- Sound systems -- A small PA might draw 2 to 5 kW. A large festival system can draw 50 kW or more per stage
- Lighting -- LED stage lighting is relatively efficient (a full rig might draw 5 to 15 kW), but traditional tungsten or discharge fixtures draw significantly more
- Catering units -- A food truck with fryers, griddles, and refrigeration can draw 15 to 30 kW. Hot food preparation is one of the biggest power consumers at any event
- Bars -- Refrigeration, ice machines, and lighting. A typical event bar draws 3 to 8 kW
- Welfare facilities -- Lighting for toilet blocks, hand dryers, and any powered welfare units
- Production offices -- Computers, printers, phone charging, lighting. Usually 2 to 5 kW
- Miscellaneous -- Fairground rides, inflatable structures, market stall lighting, CCTV
Add up all requirements and then add 20 to 25% as a buffer. This accounts for inrush currents (the surge when motors and compressors start up), equipment drawing more than its rated load, and the fact that power estimates are often optimistic.
Mains power vs generators
Indoor venues typically have mains power, but you must confirm that the available supply is sufficient. Check the venue's incoming supply rating and the capacity of the distribution board. If your event needs more than the venue can provide, you may need to arrange a temporary mains supply from the local distribution network operator, which requires lead time of several weeks.
Outdoor events usually require generators. The main types used at events are:
- Diesel generators -- The standard choice. Available from small portable units (5 to 10 kVA) up to large containerised units (500+ kVA). Diesel generators are reliable and fuel-efficient but noisy
- Super-silent generators -- Acoustically treated diesel generators with noise output as low as 65 dB at 7 metres. Essential for events where generator noise would disturb the audience or neighbours. More expensive to hire but often necessary
- Battery and hybrid systems -- Increasingly popular for environmentally conscious events. Battery units can provide silent power for low-demand areas, charged by a smaller generator running at optimal efficiency
Generator sizing is critical. An undersized generator will struggle under load, causing voltage drops that damage sensitive equipment. An oversized generator is inefficient and wastes fuel. Your power supplier should size the generator based on your calculated load including the buffer.
Distribution
Getting power from the source (mains supply or generator) to the point of use requires a distribution system. This is not something to improvise. Event power distribution should be designed and installed by a competent electrical contractor.
A typical distribution setup includes:
- Main distribution board -- Connected to the power source, this splits the supply into circuits for different areas
- Sub-distribution boards -- Located around the site, these provide power to individual users (stages, bars, catering units)
- Cable runs -- Heavy-duty cables connecting the boards. Cables must be rated for the load they carry and protected from damage by vehicles, foot traffic, and water
- Residual current devices (RCDs) -- These are mandatory for outdoor electrical installations. They detect earth faults and disconnect the supply within milliseconds, preventing electric shock
Cable routing needs careful planning. Cables crossing walkways must be ramped or buried. Cables should be kept away from water and not run through areas where they could be snagged or damaged. All connections must be weatherproof for outdoor use.
Safety requirements
Temporary electrical installations at events in the UK must comply with BS 7671 (the IET Wiring Regulations). For outdoor events, the regulations are particularly strict because of the increased risks from weather, public access, and temporary connections.
Key safety requirements include:
- RCD protection -- All circuits accessible to the public must be protected by 30mA RCDs
- Earthing -- Generators must be properly earthed. The earthing system must be tested and verified before the event
- Inspection and testing -- All temporary installations should be inspected and tested by a competent person before the event opens. This should be documented with an electrical installation condition report
- Isolation -- Every circuit must have a means of isolation (a switch to turn it off) that is accessible and clearly labelled
- Competent persons -- Electrical work at events should only be carried out by qualified electricians with experience in temporary event installations
Generator positioning and fuel
Where you place generators matters for noise, safety, and logistics:
- Noise -- Position generators as far from audience areas as practical. Even super-silent units are noticeable at close range. Use acoustic barriers or the natural lie of the land to reduce noise transmission
- Fuel safety -- Generators need refuelling during long events. Fuel storage must comply with fire safety requirements. Keep fuel in approved containers, away from ignition sources, and in a bunded area that can contain spillage
- Access -- Generators need vehicle access for delivery, refuelling, and removal. Do not position them where they could become inaccessible once the event is set up
- Exhaust -- Generator exhaust fumes contain carbon monoxide. Never position a generator where exhaust could enter an enclosed space such as a marquee or backstage area
Budgeting for power
Power costs vary enormously depending on the scale of your event. As a rough guide for outdoor events:
- Small event (up to 500 people, single stage) -- £500 to £1,500 for generator hire, fuel, and basic distribution
- Medium event (500 to 2,000 people, multiple areas) -- £2,000 to £6,000
- Large festival (2,000+ people, multiple stages) -- £8,000 to £25,000+
These figures include generator hire, fuel, distribution equipment, cabling, and the electrician. Fuel is often the biggest variable. A large diesel generator can consume 30 to 50 litres per hour at full load.
For budget planning, get detailed quotes from at least two power suppliers. Provide them with your full power schedule and site plan. A good supplier will visit the site, review your requirements, and propose a solution that is properly sized and safely configured.
Investing in proper power infrastructure is not glamorous, but it protects your production, your suppliers, and your audience. A thorough risk assessment of your electrical setup, combined with competent installation, means power is one thing you do not need to worry about on event day.
