Project Power Load Estimator

If you don’t have a load schedule yet, start here. Pick your project type and adjust the presets — you’ll get a working estimate in a couple of minutes rather than a couple of days.

How this calculation works

This tool is for the stage before you have a full load schedule: pricing a job, checking feasibility, or briefing a supplier. It builds an estimate from typical load profiles.

Construction site. Dominated by the largest motor — tower crane, hoist, concrete pump. Site accommodation, lighting and small power are usually secondary. Diversity is low, typically 70–80%, because the heavy plant doesn’t all run at once.

Outdoor event. Lighting rig, sound, LED screens, catering, air conditioning, back of house. Diversity is high — during the show, nearly everything runs. Events also need redundancy: a single point of failure in front of an audience isn’t acceptable, so the usual approach is N+1 with automatic changeover.

Villa or residential. Air conditioning dominates, typically 50–60% of total demand. Add water pumps, lighting, kitchen and general power.

Clinic or healthcare. Medical equipment, HVAC, lighting, IT. Critical loads need clean, uninterrupted supply — usually a UPS for the immediate transfer plus a generator behind it. Load quality matters as much as quantity here.

Data centre or telecoms. IT load plus cooling, which typically adds 30–50% again. Runs at essentially 100% diversity, 24 hours a day, so the set never gets a light-load rest. Redundancy is mandatory.

Always sanity check against your actual equipment. These are planning figures, not a design. Once you have a real load schedule, run it through the generator sizing calculator.

Worked example

An outdoor concert for 3,000 people:

System	Estimated load
Stage lighting	60 kW
Sound system	25 kW
LED screens	20 kW
Catering and F&B	40 kW
Back of house, offices, A/C	35 kW
Site lighting and security	15 kW

Total connected load: 195 kW. Event diversity is high — call it 90% — giving 176 kW running. At 0.85 power factor, roughly 207 kVA.

Add 20% reserve for the load nobody mentioned until the day before: 248 kVA. Derate for ambient: around 260 kVA.

But for an event you don’t order a single 300 kVA set. You order two 150 kVA sets in parallel with a sync panel, or a 300 kVA with a standby alongside. If one fails mid-performance, the show continues. The cost difference is small against the cost of a stage going dark in front of 3,000 people.

Common mistakes

Adding nameplate ratings without diversity. Massively oversizes for construction, though it’s closer to right for events.

Forgetting cooling load. In UAE conditions, air conditioning is often the largest single item.

No redundancy on critical work. Events, healthcare and data need N+1. Not optional.

Missing the late additions. Every event grows a food truck, a coffee cart and a VIP tent in the final week. Reserve capacity is not padding.

FAQ

How much power does a construction site need? Almost entirely determined by the largest motor. A site with a tower crane typically needs 300–500 kVA even when the running load is well under 150 kW.

How do I calculate power for an outdoor event? Add every system, apply high diversity (85–95%), add 20% reserve, then plan for redundancy — two smaller sets in parallel rather than one large one.

What size generator for a villa? Depends almost entirely on the air conditioning. A typical large UAE villa runs 40–80 kVA; one with a pool, extensive landscaping and staff accommodation can go well beyond that.

Do I need a backup generator? For events, healthcare and data, yes. For construction, it depends on what a stoppage costs you per day compared with the standby rental rate.