Can a solar generator run a refrigerator?

Every version of this question hides two separate questions. The first is whether the station can start the compressor. The second is how long it can keep the compressor running. People usually answer the first one, buy on that basis, and then discover the second one on the first night.

Starting a fridge is a power problem, and it is nearly solved already. A fridge that runs on 150 W needs about 600 W for roughly one second when the compressor kicks in, because the motor has to overcome pressure in the refrigerant loop before it turns. The 300 W class units we track pair that continuous rating with a 600 W surge, and 600 W of surge covers a standard fridge. The smallest stations in our own table clear it.

Running a fridge is an energy problem, and that one is not solved. Energy is power multiplied by time, so the compressor's duty cycle decides everything. A fridge does not draw 150 W all day: the compressor switches on for maybe eight hours in total and stays off for the rest. That is why the number to compare is watt hours a day, not watts.

Both numbers appear in the right-hand panel. Change the capacity and the days move; change the startup figure and the start verdict flips. The rest of this page is about which of those two numbers to trust when you are buying.

The distinction matters because the two failure modes look identical from the sofa. A station that is too small in power simply refuses: the inverter trips the moment the compressor tries to turn, the fridge clicks, and nothing happens. A station that is too small in energy starts the fridge perfectly, runs it for five hours, and then goes dark in the middle of the night. Only one of those is visible when you unbox the thing.

Surge ratings are also quoted inconsistently. Some brands print a peak figure for a fraction of a second, some print a motor-start figure for a few seconds, and some print nothing at all beyond continuous watts. Treat any station whose surge claim you cannot find as rated for continuous output only, then do the arithmetic yourself rather than assuming headroom that was never promised.

For a fridge the practical rule is simple. Continuous output needs to clear the running watts with room for the defrost heater if the unit has one. Surge needs to clear the startup watts. If both hold, the fridge will run, and every further decision is about capacity rather than about the inverter.

These are category-level figures, not readings from one specific model. The energy label on your own fridge gives the annual kWh, and dividing that by 365 gives a daily number that is more accurate than any table. Use the table to see the shape of the problem, then check the label before you size a system.

Two things stand out. First, the efficiency gap between a standard and an ENERGY STAR fridge is not a rounding difference: it is nearly 500 Wh a day, which is half a small station's entire usable capacity. Second, a chest freezer uses no more energy than a fridge of similar size, because cold air stays inside when the lid opens instead of spilling out of a door.

Older units are worse than either row. A fridge from the 1990s can draw twice the standard figure, and a failing door seal adds to that quietly. If the fridge is more than fifteen years old, assume the standard row is optimistic and check the label before trusting any runtime estimate.

The same 150 W fridge, the same 8 hours of compressor time, and the same 85 % depth of discharge. Only the capacity changes. Depth of discharge is how much of the nameplate you are willing to use before recharging; 85 % is normal practice for lithium iron phosphate packs, and using the last 15 % habitually shortens their life rather than adding useful runtime.

The pattern is uncomfortable. Doubling capacity from 1,024 Wh to 2,048 Wh buys half a day, not a day, because the fridge keeps eating 1,200 Wh every 24 hours whether or not the station is bigger. There is no capacity at which a battery stops needing arithmetic; there is only a capacity that covers the outage you actually expect.

If the answer you need is "cover one night", 1,024 Wh is enough and the extra money buys nothing. If the answer is "cover a four-day storm", 4,096 Wh is the entry point, and even that leaves nothing for lights, a router or a phone charger. Those belong in the same load budget, which is what the load calculator computes.

There is a number in this problem that is not electrical at all, and it is more useful than any runtime figure. The US Department of Agriculture advises that a closed refrigerator keeps food safe for about four hours during a power outage, and that perishable food should be discarded after that. A freezer holds far longer, because ice is already stored cold mass.

Read together with the runtime table, this changes what people should buy. A 288 Wh station covers 0.2 days of normal fridge operation, which sounds useless, and it covers the four-hour food window with room to spare. A 2,048 Wh station covers a day and a half, which sounds good, and it still cannot carry a five-day outage without recharging.

So the honest question is not "can it run my fridge" but "how long is my outage". A few hours a year, which is the common case in most US neighborhoods, is a food-safety problem solved by a small station and a closed door. Multi-day outages after a storm are an energy problem, and they need either a large station or panels, or both.

One more thing the USDA says is easy to skip: never taste food to judge whether it is safe. If the fridge has been above 40 °F for more than two hours, perishables go. A station that keeps the compressor cycling is what keeps the interior below that line, which is the real reason to size it at all.

Calculator output is the best case. Four things move the real number down, and all four are predictable.

Room temperature. A fridge in a 90 °F garage runs its compressor far more than the same unit in a 70 °F kitchen, because heat leaks in faster and the duty cycle rises. Summer outages and hot garages are exactly when people need the backup, so the worst case and the needed case coincide.

Door openings. Every opening dumps cold air and adds a compressor cycle. During an outage the temptation is to check constantly, which is the most expensive habit available. A fridge thermometer inside the door removes the need to open it.

Defrost cycles. Frost-free fridges run a heater periodically. Its draw is smaller than the compressor's but it is pure loss during an outage, and it can trip a station that was sized for the compressor alone if the two overlap with anything else running.

Inverter and battery losses. Converting DC to AC costs a few percent, and a cold battery delivers less than its nameplate. The 85 % depth of discharge used here is a deliberate buffer; treating nameplate as usable energy is how people end up an hour short on the night it matters.

None of this argues for buying a much larger station. It argues for expecting roughly 80 % of the calculated figure in a hot garage, and for keeping the door shut.

Past about two days, battery capacity stops being the limiting factor and generation becomes it. A station that can be refilled never runs out; one that cannot is a countdown. The arithmetic is the same as any array sizing: daily energy divided by peak sun hours, then divided again by system efficiency, then rounded up to whole panels.

For a 1,200 Wh a day fridge at 4.5 peak sun hours and 80 % efficiency that is about 333 W of panels, which is one 400 W panel in good sun and two in a cloudy week. That is a real constraint: a panel that size needs somewhere to sit, and the panel count calculator works it through for your own sun hours and panel size.

The trap is assuming that because a station accepts a solar input, recharging is solved. Input limits are the bottleneck: many compact stations cap panel input well below what a 400 W panel can deliver in good sun, so the extra panel capacity is clipped and wasted. Check the solar input rating before buying panels to pair with a specific station, and read the plug-in panel comparison if you are choosing panels and an inverter as a set.

Every unit below is in the current US market and is grouped by what it actually delivers for a fridge, not by marketing tier. Capacity, continuous output and surge are the three numbers that matter here; the fourth, price, is left to the retailer because a printed price is stale by the time you read it. For the full comparison across more units and more situations, see the portable power station ranking.

Notice what is not in this list: any unit justified by its brand or by a claim about "whole home" backup. For a refrigerator the ranking is capacity, then continuous output, then surge, then price on the day. A station twice the capacity of another is a different class of product; the same capacity from two brands is the same fridge experience.

Buying on watts alone. A 2,000 W station and a 1,000 Wh station are not competing specs; one is about starting, the other about running. A 500 W fridge compressor can be started by a station whose energy lasts four hours.

Confusing surge with peak. Peak is often a millisecond figure for electronics. Motor starting needs a second of headroom. Two stations advertising the same number can behave differently when a compressor tries to turn.

Sizing to the fridge and forgetting everything else. The fridge is 1,200 Wh a day; lights, a router and two phones add several hundred more. Sizing to the compressor alone is how a station ends up dead by midnight.

Assuming panels fix a small battery. Panels extend an outage and cannot shorten a night. A 400 W panel produces nothing at 9 pm, which is exactly when the fridge is still on.

Ignoring the food line. If the plan is to bridge four hours, a small station is the correct purchase and a large one is wasted money. If the plan is to bridge four days, the small station is a false economy. Deciding which one you are buying is the whole task.

If you already know the daily energy you need across everything in the house, the storage sizing calculator turns it into a nameplate figure and tells you when you have left the single-box category. If you are weighing a battery against panels instead, the plug-in solar comparison covers the generation side.

More appliance figures, including starting watts for pumps and workshop motors, are in the appliance wattage table.

Every figure on this page can be recomputed by hand: daily energy is running watts multiplied by compressor hours, usable energy is capacity multiplied by depth of discharge, and runtime is the second divided by the first. If a number here disagrees with your own calculation, the calculator in the right-hand panel is the source of truth, and the changelog records every time one of these values changed. Our method and the way corrections are published are described on the disclosure page, and the privacy page covers what this site does and does not collect.