Making a loads list: which circuits matter in an outage

A loads list is a written inventory of what you want powered when the grid is down. It has nothing to do with brands or battery sizes yet. It's about your house and your habits.

Walk the house and write everything down

Go room by room. Include the obvious things and the hidden ones. Hidden ones don't look like appliances. Think of a doorbell transformer, a garage door opener, a sump pump or the router in the hall closet.

For each item, write down:

• What it is and where it is.
• Which breaker feeds it. Read the labels on your main panel, and note that labels can be wrong. Ask your electrician to trace each circuit. Don't take the panel cover off.
• Whether it plugs in or is hard-wired.
• Whether it runs on a regular circuit or a large one (large ones usually have a double-width breaker).

Sort into three groups

Must stay on. Things where losing power is a problem for health or for the building. Ready.gov flags medical equipment: "Have alternate plans for refrigerating medicines or using power-dependent medical devices."¹ Talk to your care provider about your own needs. This site can't advise on that.

Nice to have. Lights in the rooms you'd actually sit in. A TV. A microwave. Internet equipment.

Can wait. Large heating and cooling loads, the oven, the dryer, the pool pump. These are the loads that often get left off. The big-loads page covers them: Big loads that need care.

Be hard on the "must" group. Each thing you add makes the system bigger and the quote higher, and it leaves less battery for the things that matter.

Think about time as well as power

Some things can go off for a while and nothing happens. A fridge is one. Ready.gov says "The refrigerator will keep food cold for about four hours" if you keep the door closed.¹ That doesn't mean it should be left off, but it affects how you rank it. Write a rough duration next to each item: a few minutes, a few hours, all day.

Heating and cooling equipment is one example. Some transfer switches "allow for load shedding or prioritization of optional circuits."² Ask your electrician whether the system you're considering can do something like that.

What backup is meant to cover

A home battery is meant to cover outages.³ How much of the list it handles depends on the product and its settings, so check the maker's manual.

Then add the numbers

Once the list is sorted, each line needs its power draw in watts and, for big loads, in amps. That comes from the appliance label or manual. Where to look is covered in finding watts and amps on labels.

Leave a blank if you can't find it. A blank is better than a guess, and your electrician can sort it out.

Keep it short and keep it

Aim for a page. Date it. Note anything you plan to buy soon, such as a new heat pump or an EV charger, because those change the answer. The electrician page lists what else to bring.