A conference power requirements calculation is not a formality to complete after the stage design is approved. It is the point at which an attractive production plan becomes either deliverable or dangerously expensive. Get it wrong and you may face overloaded circuits, last-minute generator hire, restricted catering service, a dark registration area or an AV system that cannot be switched on safely.
Power is often treated as the venue’s problem. It is not. The venue owns the infrastructure, but the organiser owns the consequences of unclear requirements. My practical approach is to calculate the likely demand early, allow sensible headroom, then ask the venue and production supplier to confirm exactly how that demand will be supplied, distributed and charged.
Start with the real show, not a vague estimate
The most common early question is: “How much power do you need?” A reply of “enough for AV” is not a requirement. It is an invitation for assumptions.
Begin with a current equipment schedule. This should cover every item that draws power, including the equipment that is easily forgotten because it sits outside the main conference room. Think about registration printers and badge machines, speaker-ready rooms, digital signage, exhibition stands, charging points, catering equipment, interpretation booths, streaming encoders, backstage work lights and production office equipment.
For each item, record its rated wattage or amperage, quantity, location and expected period of use. Your AV supplier should produce this for the technical package. If they cannot, ask for it before agreeing the power order. The venue electrician cannot reliably design a distribution plan from a floorplan showing “stage”, “screens” and “coffee station”.
A useful working table separates the requirement into zones: plenary, breakouts, registration, exhibition, catering, back of house and external areas. This matters because a total building load may look manageable while one room, or one side of a room, has insufficient circuits.
The basic conference power calculation
At its simplest, electrical load is measured in watts (W) or kilowatts (kW). One kilowatt equals 1,000 watts. Add the rated load of the equipment expected to operate at the same time:
`Total load in kW = total watts ÷ 1,000`
If a plenary uses 12 LED fixtures at 180W each, two projectors at 900W each, a video system at 1,200W and audio equipment rated at 2,000W, the connected load is:
`(12 × 180) + (2 × 900) + 1,200 + 2,000 = 7,160W, or 7.16kW`
That is not yet the power order. You then need to consider operating load, diversity and contingency. Some equipment rarely reaches its maximum rating; other equipment, particularly heating elements and motor-driven equipment, can create high starting loads. Your technical supplier should apply realistic knowledge here. Do not simply reduce every figure because “it probably will not all be on”.
For a typical conference AV package, I would normally want a contingency margin of at least 20 per cent, subject to the equipment involved and the venue’s distribution arrangement. In the example above, 7.16kW becomes roughly 8.6kW. If the show includes LED walls, high-output lighting, broadcast cameras, exhibition catering or temporary structures, the margin and engineering review may need to be greater.
Watts, amps, kVA and phases: ask before you order
Venue power quotations can be confusing because suppliers may describe capacity in amps, kW or kVA. They are related, but they are not interchangeable without context.
In the UK and much of Europe, a standard single-phase supply is typically around 230V. A simple guide is:
`Watts = volts × amps`
So, a 13A socket at 230V can theoretically supply close to 3kW. In practice, you should not plan to run it continuously at its absolute limit. Cable lengths, shared circuits and the equipment’s actual draw all matter.
Larger conference systems often use three-phase power, commonly around 400V. Three-phase distribution is useful when substantial loads need to be divided across phases, such as a large lighting package, exhibition hall or temporary kitchen. It is not just “more power”. It needs competent design and load balancing. An uneven load can cause nuisance trips and restrict usable capacity.
kVA adds another complication. It is apparent power, while kW is real power. The difference depends on power factor, which varies by equipment. Modern switch-mode power supplies can be efficient, but do not assume a one-to-one conversion in a quote. Ask the supplier: “Is this capacity stated in kW or kVA, what power factor have you used, and is the figure available load or total supply capacity?” That question alone can prevent an expensive misunderstanding.
Do not put AV, catering and exhibitions on the same assumption
A conference can have three separate power stories: show power, venue operational power and exhibitor power. Treating them as one number is risky.
The AV contractor needs clean, appropriately protected power in the right locations, often separated from heavy or variable loads. Catering may require substantial electrical capacity for ovens, hot cupboards, coffee machines and dishwashing. Exhibitors may request small socket supplies, but a stand with refrigeration, demonstration equipment or its own lighting can exceed the standard allowance quickly.
The hidden issue is often distribution. A venue may confirm that it has 100kW available, but that does not mean 100kW is available at your stage, on your exhibition floor or in the courtyard where a registration structure is being built. Temporary power distribution, cabling routes, floor protection, cable ramps and labour to install and remove them may all be chargeable.
Ask for a marked-up power plan showing the origin of supply, circuit ratings, distribution boards and socket positions. If the answer is that this will be decided on site, that may be acceptable for a small, simple meeting. It is not sufficient for a high-stakes conference with a complex build.
Build a margin without paying for fantasy capacity
There is a trade-off. Under-ordering power creates operational risk, while ordering excessive capacity can inflate the budget, especially where a venue charges per kW, per connection or for a dedicated technician.
The right answer depends on the programme. A one-day leadership meeting with two screens and a modest PA has a different risk profile from a pharmaceutical congress with interpretation, poster displays, sponsor stands, live streaming and an evening reception. The latter needs formal technical coordination, not a worksheet passed between departments.
Avoid using contingency as a substitute for missing information. A 30 per cent margin on a poor estimate is still a poor estimate. First establish the connected load by zone. Then add contingency for late additions, inrush current, reasonable equipment variation and operational resilience. Finally, identify what must remain live if another system fails. Registration, emergency lighting, critical networking and show-control systems may need a protected or backed-up approach.
Questions to settle with the venue and suppliers
Before signing off power, get clear written answers to the following points:
- What electrical capacity is included in the room hire, and what is charged separately?
- Which supplies are single-phase and which are three-phase?
- Are circuits dedicated, shared with other venue operations, or shared with another event?
- Where are the supply points, and who provides distribution, cabling and cable protection?
- Is a venue electrician compulsory, and what are the minimum call-out, connection and out-of-hours charges?
- Are generators permitted or required for outdoor, temporary or resilience-critical installations?
- What testing, certification and equipment safety documentation are required before connection?
These are contract questions as much as technical ones. A venue may quote an attractive day rate then charge separately for every connection, extension lead, technician hour and overnight energisation. None of those charges is automatically unreasonable. The problem is discovering them after the production design has been promised to stakeholders.
A practical approval process
I recommend appointing one person to own the master power schedule. That person does not need to be an electrician, but they do need authority to stop unapproved additions. Every supplier should submit requirements against the same version of the floorplan and programme.
Review the schedule at three points: before contracting the venue, before final production orders, and again shortly before build. The final review catches late changes such as extra sponsor screens, a relocated coffee station, additional interpretation equipment or a revised streaming plan. These are ordinary conference changes. They become costly only when they appear after cabling and distribution have been installed.
On site, ask the production manager or qualified electrical lead to confirm that circuits are labelled, loads are distributed as planned and cable routes do not create trip hazards or obstruct evacuation. Do not ask unqualified staff to alter distribution boards or reconnect equipment. Conference power is safety-critical work.
A well-prepared power plan rarely attracts applause from delegates. That is precisely the point. The screens light up, the coffee flows, registration opens on time and nobody has to explain why a single overloaded socket has interrupted the opening session. That quiet reliability is what your calculation is buying.