Solar · Heating & hot water

How many solar panels to run a space heater?

A typical space heater uses about 6.00 kWh a day in the months you use it (about 120 days a year), based on 1,500 W for 4 hours a day, 120 days a year (720 kWh/yr). Off-grid with a battery, that takes about 2,920 W of solar panels (15 × 200 W) to keep up in December, the worst month in Tennessee (the middle state for sunshine), or 2,060 W in an average month, plus a battery of about 7,060 Wh. On a grid-tied home system it adds about 720 kWh a year: 0.49 kW, or 2 × 400 W panels.

Energy use6.00 kWh/dayper day of use
Off-grid panels2,920 Wworst month, Tennessee
Battery, 1 day7,060 Whpower station or lithium
Grid-tied2 × 400 W720 kWh/yr

Appliance energy: our space heater page (sources there) · solar: Global Solar Atlas 2.0 · solar data reviewed 2026-11-05

Can a panel and battery keep it running where you are?

Your situation: keeping a space heater running on solar. Different situation?

1

Your battery and panel

Battery size in

On the box: a station’s Wh is its battery; a panel’s W is its rated output. A 12 V 100 Ah battery is 1,200 Wh.

2

Where and how

Watts and hours for a different model or use: change them on the off-grid sizer, which adds up several appliances.

By state

Off-grid columns size the panels for the month named (with 85% charging and 85% inverter losses). The grid-tied column covers its yearly use on a home system.

Panels to run a space heater in every state
StateOff-grid, worst monthOff-grid, average monthGrid-tied, 400 W panels
Alabama2,630 W1,990 W2
Alaska12,750 W2,810 W2
Arizona1,890 W1,590 W1
Arkansas2,620 W2,000 W2
California2,200 W1,700 W2
Colorado2,080 W1,740 W2
Connecticut2,940 W2,070 W2
Delaware2,840 W2,070 W2
District of Columbia2,710 W2,070 W2
Florida2,220 W1,880 W2
Georgia2,530 W1,960 W2
Hawaii2,200 W1,810 W2
Idaho3,770 W1,900 W2
Illinois3,510 W2,130 W2
Indiana3,660 W2,160 W2
Iowa3,310 W2,090 W2
Kansas2,510 W1,930 W2
Kentucky3,340 W2,130 W2
Louisiana2,520 W1,960 W2
Maine3,280 W2,140 W2
Maryland2,810 W2,090 W2
Massachusetts3,080 W2,120 W2
Michigan4,590 W2,260 W2
Minnesota3,630 W2,140 W2
Mississippi2,600 W1,960 W2
Missouri2,790 W2,020 W2
Montana3,710 W2,060 W2
Nebraska2,830 W2,010 W2
Nevada1,980 W1,580 W1
New Hampshire3,100 W2,130 W2
New Jersey2,950 W2,110 W2
New Mexico1,840 W1,580 W1
New York2,900 W2,080 W2
North Carolina2,470 W1,970 W2
North Dakota3,760 W2,090 W2
Ohio4,070 W2,240 W2
Oklahoma2,350 W1,890 W2
Oregon5,070 W2,330 W2
Pennsylvania3,070 W2,140 W2
Rhode Island2,890 W2,090 W2
South Carolina2,400 W1,940 W2
South Dakota3,010 W2,010 W2
Tennessee2,920 W2,060 W2
Texas2,540 W1,990 W2
Utah3,100 W1,860 W2
Vermont4,670 W2,320 W2
Virginia2,520 W2,000 W2
Washington5,790 W2,350 W2
West Virginia3,710 W2,250 W2
Wisconsin3,710 W2,140 W2
Wyoming2,480 W1,830 W2

FAQ

How many solar panels to run a space heater?

A typical space heater uses about 6.00 kWh a day in the months you use it (about 120 days a year), based on 1,500 W for 4 hours a day, 120 days a year (720 kWh/yr). Off-grid with a battery, that takes about 2,920 W of solar panels (15 × 200 W) to keep up in December, the worst month in Tennessee (the middle state for sunshine), or 2,060 W in an average month, plus a battery of about 7,060 Wh. On a grid-tied home system it adds about 720 kWh a year: 0.49 kW, or 2 × 400 W panels.

Can a 200 W solar panel run a space heater?

Not on its own in Tennessee: even in the best month a 200 W panel puts back less than a typical space heater uses (6.00 kWh a day). It takes about 2,920 W to keep up all year, at 85% charging and 85% inverter efficiency. A panel alone can’t run it at night or under cloud; the battery does that.

What size battery do I need for a space heater on solar?

About 7,060 Wh to cover one day without sun (a day’s use ÷ 0.85 inverter efficiency, for a power station or lithium battery). Double it for lead-acid, which shouldn’t be run below half.

How many kWh does a space heater use a day?

About 6.00 kWh a day in the months you use it (about 120 days a year), based on 1,500 W for 4 hours a day, 120 days a year (720 kWh/yr). Your own use depends on the model and how you use it.

Sources and assumptions

Note: These are estimates; shading, roof direction, local weather, equipment and your installer’s design change the real output. We give no wiring or installation advice: follow your equipment’s manuals, and use a licensed installer for any system connected to your home’s wiring or the grid. Net metering and export credits are not modelled. Not financial or tax advice.

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