What Size Solar Panel Do I Need for a Space Heater (electric)?

1500W running draw8h/day defaulthvac

Quick Answer

A Space Heater (electric) at 1500W needs at least 3900W of solar panels to run sustainably. Running 8 hours per day draws 12.0 kWh daily. You need 3900W of solar total (20 panels at 200W each). Pair with a 3000Ah LiFePO4 battery at 12V for 2-day cloudy weather reserve. The EcoFlow Delta Pro is the simplest all-in-one solution for this load.

System Specs for a Space Heater (electric)

Calculated for 8 hours/day usage, 5 peak sun hours, and 2-day LiFePO4 battery autonomy.

ComponentMinimum SizeDetails
Daily Energy12.0 kWh1500W for 8h
Solar Panels3900W20x 200W or 39x 100W panels
Battery3000Ah at 12VLiFePO4, 2-day reserve (36.0 kWh usable)
Charge Controller410A MPPTHandles up to 3900W panel input at 12V

Running more than just a space heater (electric)? Add more appliances to your load with our full calculator

Recommended Power Station

EcoFlow Delta Pro

3,600Wh expandable to 25kWh, 3,600W AC output — whole-home backup and heavy off-grid use.

3,600Wh

Capacity

3,600W

AC Output

1600W

Max Solar In

Buy on EcoFlow.comView with Solar Panel Bundle

DIY Component List

Building your own system for a space heater (electric)? These components match the specs above.

Solar Panel

3900W total

Renogy 400W Solar Starter Kit (2x200W + MPPT) on Amazon

Battery

3000Ah 12V LiFePO4 minimum

LiTime 12V 200Ah LiFePO4 on Amazon

Charge Controller

410A MPPT minimum

Renogy 40A MPPT Rover on Amazon

About the Space Heater (electric) Solar Load

An electric space heater draws 750 or 1,500 watts depending on setting. Running 8 hours per day on high produces 12,000Wh of daily consumption — making it the most power-intensive common household appliance by far. Space heaters are generally impractical for solar-only systems unless used sparingly or in very small spaces like a van or tiny home.

Frequently Asked Questions

Can I run a space heater on solar power?▼
A space heater at 1,500W running 8 hours uses 12,000Wh per day. That requires 3,200W of solar panels just to break even, plus an enormous battery bank for overnight use. This is the equivalent of running 10 refrigerators simultaneously on solar. The honest answer: electric space heaters are incompatible with solar-only systems at full runtime. The practical alternative is to use a propane heater like the Mr. Heater Buddy (no electricity required) for primary heating and a small electric space heater on a timer for 1–2 hours of morning warm-up on a large solar system.
What is the most energy-efficient off-grid heating option?▼
Propane and wood are the only practical primary heat sources for off-grid living. A Mr. Heater Big Buddy runs on a 1-pound propane canister for 3 hours with zero electrical draw. A pellet stove with an electric auger draws 100W for operation and provides serious BTU output. For small spaces (van, tiny home), a diesel or propane heater like the Webasto or Propex HS2000 draws 10–15 watts for controls and fans, making them entirely feasible on solar. Electric heat is only appropriate as a supplementary source in a well-insulated space with a large solar array.
How long can a power station run a space heater?▼
Not long. A 1,500W space heater on the EcoFlow Delta Pro (3,600Wh) lasts 2.2 hours on a full charge. The EcoFlow Delta 2 Max (2,048Wh) lasts 1.2 hours. These are fine for taking the chill off a room in the morning, but not for all-night heating. If you are evaluating a power station for emergency home heating, plan on using the 750W low setting and expect roughly twice the runtime. Solar recharge cannot keep up with full-power space heater operation — the heater consumes more than even a 400W panel can produce.

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Running more than just a space heater (electric)?

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