House · pedestal · generator · solar

How you power the box

A shed on a house circuit, a trailer on a festival pedestal, a generator at an event, or solar off-grid. Generator is one option, not the assumption.

Power source Where does the AC plug in?

Air conditioner

AC size How many units

Running watts per unit Compressor type

Compressor running time (% of the day)

A well-sized, well-insulated box runs 30–50% of the time. Hot days and busy doors push it toward 70%+.

Other always-on load (controller, lights, fans) in watts

House / shop Electricity price ($ per kWh)

California residential is often $0.35–0.50. The US average is closer to $0.17.

Circuit

Event / campground pedestal Receptacle Hours plugged in per day

Pedestals are often metered or included in a stall fee. This sheet only checks whether the AC will trip the breaker.

Generator

Fuel Fuel price ($ per gallon)

Hours per day on generator

Solar + battery What has to run on batteries

Peak sun hours Custom sun hours

Peak sun hours are not clock hours. They already bake in weather and season for a typical year.

Battery Cloudy days to cover

Battery bank voltage

Panels, $ per watt Battery, $ per kWh

DIY parts only — panels and cells, not racks, wire, or a pro install. Change the dollars to match a quote.

On the meter

–

Average load
Running watts (compressor on)
Starting (surge) watts
Energy per day
Cost per day
Cost per year
Circuit continuous rating
Pedestal continuous rating
Generator size
Fuel per event day
Fuel cost per event day
Battery pack
Inverter (continuous / surge)
Solar array
Charge controller
Panels + battery (parts)

Start-up surge is the trap on every source

A standard window AC draws about three times its running watts for the first second the compressor starts. That trip happens on a generator, a 20A house circuit, or a festival pedestal. Inverter ACs (soft start) are much easier on all three.

Which source

House / shop. A shed or indoor cooler. Put the AC on its own 20A circuit. Cost is kWh on the bill.
Event pedestal. Trailer at a fair or campground. Check amps before you worry about fuel.
Generator. No pedestal, or you are away from the building. Size for surge, then fuel.
Solar. Off-grid farm box, or a trailer that sits. Battery covers night (and extra cloudy days if you ask). Array covers the day's kWh. The inverter has to start the compressor — that is usually the expensive part, not the panels.

Assumptions

Continuous circuit ratings use 80% of breaker amps (NEC). Generator fuel is a typical inverter curve (about 0.07 gal/h idle plus 0.11 gal/h per kW for gasoline; propane about 1.4× that volume). Solar: battery kWh = (average watts × hours on battery × cloudy days) ÷ usable fraction (80% lithium, 50% lead-acid). Array watts = daily kWh ÷ peak sun hours ÷ 0.70 (dirt, heat, angle). Charge-controller amps = array watts ÷ battery voltage ÷ 0.8. Inverter continuous is running watts + 25%; surge is the compressor start. Parts cost is panels and battery only. Not an electrical design.