During an outage the temptation is to plug in whatever stops working, in the order it stops working. That approach empties a battery faster than almost anything else, because the largest consumers are rarely the things you notice first.
A better order starts with what preserves value, then what preserves safety and communication, then comfort. Working it out before an outage takes ten minutes and doubles what a given battery achieves. Our note on what a solar generator can run covers the capacity arithmetic.
A Safety Note
Never connect a generator of any kind to house wiring without a transfer switch installed by a licensed electrician. Medical equipment requiring uninterrupted power needs a plan made with your provider rather than a portable battery, and anyone dependent on such equipment should contact their utility about priority restoration.
Quick Answer
Refrigeration first, then phones and communication, then lights, then medical or work-critical equipment as your situation requires. Leave heating, cooling, and cooking off battery unless you have substantial capacity.
First: Refrigeration
A fridge or freezer represents real money in food and it fails gradually rather than immediately, which makes it the highest-value early load.
Refrigerators also cycle on and off rather than running continuously, so their average consumption across a day is considerably lower than the running wattage on the plate suggests. That makes them far more affordable on battery than most people expect.
The startup surge is the thing to check before relying on it. Compressors draw several times their running wattage for a moment when they kick in, and a generator perfectly capable of the running load can still shut down on that spike.
A closed fridge holds temperature for hours without power, so cycling it on intermittently works better than running it continuously. Our note on preparing for a power outage covers the wider plan.
Second: Communication
Phones, a router, and a modem together consume very little power and provide outage updates, weather warnings, and the ability to call for help if something goes wrong.
This is the best return on watt-hours available on the whole list. A large battery can keep phones and a router running for days on a small fraction of its capacity.
A laptop belongs in this group too if you need it for work, since laptops are remarkably efficient compared with anything containing a heating element or a motor.
Third: Light
LED lighting draws almost nothing, and a few lamps on battery cost a negligible share of capacity while making everything else easier.
Rechargeable lanterns and headlamps are better still, since they run from their own internal cells and leave the generator free for the things that genuinely need it.
Avoid running whole-house circuits for lighting even where you have a transfer switch, since incandescent fixtures and always-on standby loads add up. Our roundup of lighting kits covers standalone options.
What to Keep Off Battery
Anything that heats
Space heaters, kettles, toasters, hair dryers, and electric ovens draw enormous power. A single space heater can empty a large battery in an hour or two.
Air conditioning
Compressor-driven cooling is among the heaviest household loads and rarely practical on a portable battery for meaningful duration.
Electric cooking
A propane camping stove used safely outdoors accomplishes the same thing at a fraction of the energy cost.
Electric water heating
Immersion heaters are heating elements by another name, with the same consequences for a battery.
Work Out Your Numbers Beforehand
Every appliance carries a label stating its wattage, and collecting those figures before an outage takes one pass through the house with a notebook.
Multiply watts by the hours you expect to run each thing, and the total in watt-hours is what you are asking the battery to deliver. Comparing that against the generator’s capacity tells you immediately whether the plan is realistic.
Fridges need adjusting for cycling. A unit rated at a given wattage does not draw that continuously, so its daily consumption is well below wattage multiplied by twenty-four hours. Manufacturer figures for annual consumption are more useful here than the plate rating.
Doing this once and writing the result somewhere findable means the decisions during an actual outage are already made. Our roundup of battery monitors covers watching consumption in real time.
Sequencing Through a Day
During daylight, when panels are producing, run the heavier intermittent loads. Cycling the fridge, charging devices, and running anything optional belongs in the middle of the day when input offsets consumption.
Overnight, drop to the minimum: router, phones charging, and one light. Everything else can wait for morning, and preserving overnight capacity is what carries you to the next day’s solar input.
That daily rhythm is the difference between a generator that lasts an outage and one that is empty on day two. Our note on sizing a solar generator covers matching capacity to that pattern.
Reducing the Load Instead
The cheapest watt-hour is the one you do not spend, and several substitutions cost almost nothing while removing large loads from the battery entirely.
Cooking on a propane camping stove outdoors handles meals without touching stored capacity. Rechargeable lanterns and headlamps cover lighting from their own cells. A vacuum flask of boiling water made while power was still on provides hot drinks for most of a day.
For cooling, closing blinds against sun and opening windows overnight does more than most people expect, and a small fan uses a tiny fraction of what air conditioning does while making a warm room considerably more tolerable.
For warmth, layers and blankets are free where a space heater is the single most expensive thing you could plug in. None of this is glamorous and all of it extends a battery further than any efficiency setting will. Our note on what a solar generator is covers the basics.
Check Surge, Not Just Running Watts
Anything with a motor or compressor draws a brief startup surge well above its continuous rating. Fridges, freezers, pumps, and power tools all do this.
Generator specifications list continuous output and surge capacity as two separate figures, and the surge number is the one that determines whether a given appliance will start at all.
Starting one motor load at a time rather than several together avoids overlapping surges, which is a common cause of unexpected shutdowns. Our roundup of power inverters covers the component doing the work.
Solar Generator Load Order FAQ
What should I plug in first?
Refrigeration, because it protects real value and consumes less on average than its running wattage suggests. Communication comes second, then lighting, both of which cost very little capacity for a large practical benefit.
Can I run my fridge all day?
Often yes, since fridges cycle rather than running continuously. Cycling it on intermittently works even better, because a closed fridge holds temperature for hours and running it constantly wastes capacity.
Why can I not run a space heater?
Heating elements convert electricity directly to heat, which requires enormous power. A single space heater can drain a large portable battery within an hour or two, which is rarely a good use of stored capacity.
What about air conditioning?
Compressor-driven cooling is among the heaviest household loads. Some large units with high output can run a small air conditioner briefly, and sustaining it through an outage generally is not practical.
How do I know if something will start?
Compare the appliance’s surge draw against the generator’s surge rating rather than its continuous rating. Motors and compressors draw several times their running wattage momentarily, which is what causes unexpected shutdowns.
Should I run things during the day or at night?
Heavier intermittent loads during daylight when panels are producing, and the bare minimum overnight. Preserving overnight capacity is what gets you to the next day’s solar input rather than to an empty battery.
Can I cook on a solar generator?
Anything with a heating element is a poor use of capacity. A propane camping stove used safely outdoors does the same job for a fraction of the stored energy, which leaves the battery for refrigeration and communication.
What about medical equipment?
Anyone dependent on powered medical equipment needs a plan made with their provider rather than a portable battery, and should contact their utility about priority restoration. This is not a situation to improvise during an outage.
For the wider picture, see our guide to how to choose a solar battery.
