Battery & Tech Basics
9 Things a Solar Generator Will NOT Run
Every product page tells you what these can power. Nobody tells you what they can't. Here is the honest list, with the numbers.
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What's in this article
Every product page lists what these things can power. Almost nobody publishes the other list. So here it is, with the arithmetic.
The nine
1. Central air conditioning
Several thousand watts continuously, plus a large compressor surge. Even a 4,000Wh system manages maybe an hour, and most units can't start it at all.
Instead: one room, curtains shut, two box fans. About 150W total, which a 1,000Wh unit carries most of a night.
2. Electric furnace or heat pump
Same problem, opposite season. Electric heat is measured in kilowatts.
Instead: if your heat is gas or propane, you only need the furnace blower — around 400 watts, cycling. That heats your whole house on a modest battery, and it is the single best use of backup power in cold country.
3. Space heater
The one people are most surprised by.
A 1,500W heater eats a full kilowatt-hour every 40 minutes. There is no efficiency trick — electricity to heat is one-for-one.
| Unit | Space heater runtime |
|---|---|
| 1,000Wh | ~34 min |
| 2,000Wh | ~68 min |
| 4,000Wh | ~2 hr 15 min |
Instead: layers, one closed room, and everyone sleeping together. Bodies are 100-watt heaters that need no charging.
4. Electric water heater
4,500 watts, running for a long time. Not a conversation.
Instead: two days of cold showers, or boil a pot on a camp stove.
5. Electric range or oven
2,000–5,000W per element, and an oven runs for an hour.
Instead: camp stove, or a microwave in short bursts — a microwave is brutal per minute but you only use it for two.
6. Clothes dryer
240V, huge draw, long cycle.
Instead: a clothesline. Genuinely.
7. Well pump (on anything normal-sized)
800W running, but a ~2,500W startup spike and usually 240V. verify Most portable units have neither the surge nor the right outlet.
Instead: fill the bathtub before the storm. 40–60 gallons covers flushing and washing for two or three days and costs nothing.
8. Window air conditioner, overnight
This one runs — it just doesn't last.
| Appliance | EcoFlow DELTA 21,024 Wh | Bluetti AC200L2,048 Wh | EcoFlow DELTA Pro 34,096 Wh |
|---|---|---|---|
| Window AC (5,000 BTU)~500W running, cycles ~70% of the time | 2.5 hr | 5.0 hr | 9.9 hr |
| Space heater (1500W)~1500W running | 35 min | 1.2 hr | 2.3 hr |
| Box fan~75W running | 12 hr | 23 hr | 46 hr |
| Full-size refrigerator~150W running, cycles ~35% of the time | 17 hr | 33 hr | 66 hr |
Look at the box fan row against the AC row. Same batteries, completely different outcome.
9. Your whole house
The one every product photo implies and no portable unit delivers.
A typical US home uses around 30 kWh a day. verify A 1,000Wh station holds one kilowatt-hour — about 45 minutes of normal household consumption.
Instead: stop trying to run a house. Run four things in it: the fridge, the internet, the phones, and a fan or the furnace blower. That's roughly 350–400 watts and it's what an outage actually takes from you.
The pattern
Two questions predict everything on this list:
Does it make heat or cold with electricity? Heater, oven, dryer, water heater, AC. Physics says these are expensive and no battery changes that.
Does it have a big motor? Well pump, AC compressor, large power tools. The startup spike is the problem, not the running draw.
Everything else — lights, fridge, internet, TV, laptops, phones, CPAP, fans, a furnace blower — is comfortably within reach of a 1,000Wh unit.
The picks, in detail
Specs come from data/products.json, so they're the same everywhere on this site.
EcoFlow
EcoFlow DELTA 2
The one most people should buy. It refills fast enough that a short sunny break between storm bands actually matters.
- Capacity
- 1,024 Wh
- AC output
- 1,800W
- Weight
- 27 lb
What's good
- Wall recharge is genuinely quick — useful when power flickers back for an hour
- LiFePO4 cells, so it tolerates being left plugged in for years
- Six AC outlets means no daisy-chained power strips on the kitchen counter
- Add an extra battery later instead of buying a whole second unit
What's annoying
- The fan is audible in a quiet bedroom at night
- 1800W ceiling rules out most space heaters and hair dryers
- Expansion batteries cost nearly as much as the unit itself
Who this is wrong for
Anyone who needs to power a well pump, an electric water heater or a central AC. It will not start them, and it is not a whole-home unit.
Bluetti
Bluetti AC200L
Specs unverifiedA lot of battery for the money, with the port selection of a small workshop.
- Capacity
- 2,048 Wh
- AC output
- 2,400W
- Weight
- 61.9 lb
What's good
- Expandable, unlike most Bluetti units at this size
- A genuinely useful spread of ports including a 30A RV outlet
- Fast recharge for a 2kWh unit
What's annoying
- Shorter warranty than EcoFlow and Jackery offer
- Big and awkward to store
- Bluetti's US service turnaround has been inconsistent
Who this is wrong for
Small apartments. It's physically large and you will trip over it.
EcoFlow
EcoFlow DELTA Pro 3
Specs unverifiedThe first portable unit that can honestly claim to back up parts of a house, including 240V circuits.
- Capacity
- 4,096 Wh
- AC output
- 4,000W
- Weight
- 113 lb
What's good
- 240V output covers well pumps and some dryers, which almost nothing else portable does
- Pairs with a transfer switch so you stop running extension cords through a window
- Chains with extra batteries into genuinely serious capacity
What's annoying
- Costs about the same as a permanently installed standby generator once you add a transfer switch
- 113 lb means it lives where you put it
- The install to make it useful is an electrician job, not a weekend project
Who this is wrong for
Anyone who wants to move it more than once. It has wheels for a reason, and stairs will beat you.
Questions people actually ask
What can a solar generator not run?
Why can't a power station run a space heater?
Can any solar generator run central air conditioning?
What about an electric dryer or oven?
So what should I use instead for heat and cooling?
Who wrote this
GreenCommuteGuide Editorial Team
Research and fact-checking
We research backup power the boring way: manufacturer spec sheets, UL and FCC filings, warranty documents, and the complaints buried on page four of the reviews. When we haven't tested something ourselves, we say so on the page instead of pretending.
- · Every spec on this site is checked against the manufacturer's current published documentation before publication
- · We do not accept payment for a rating, a ranking, or a positive verdict
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