Can you run a Space Heater off a Solar Panel?

You can run a space heater on solar panel energy. However, running a space heater on high heating settings continuously gets expensive quickly.

Quick answer: Yes, you can run a space heater off a solar panel. One solar panel produces enough energy to run one space heater on full power for 1.2h a day. To run a space heater continuously, you need 20 solar panels. Wood-burning stoves or propane gas heaters are more cost-effective for off-grid heating.

In this article, we’re checking exactly how many solar panels you need to power a space heater in different circumstances. Also, we’re going to cover heating methods that are a lot more cost-effective.

So, stick out to the end.

How much power does a solar panel produce?

An average solar panel produces between 250W and 400W of power in the summertime. In the wintertime, however, power production decreases significantly due to the lack of sunshine.

On an average day, a solar panel produces 1.8kWh of energy. That’s the amount of energy needed to run a 1.8kW device for 1 hour.

How much power does a space heater need?

An average space heater consumes 1,500W on maximum heat settings. However, in normal circumstances, the average power consumption of a space heater is closer to 1,000W.

The reason for the reduced power consumption is the built-in thermostat. A thermostat is a small device that measures the current temperature in a room and adjusts the power consumption of a heater accordingly.

Shortly after turning on, a space heater consumes a peak power of about 1,500W. When it senses a rise in room temperature, it decreases the power consumption or turns off the heating overall.

The exact wattage a space heater consumes in your home depends on the insulation of your room and the current room temperature. Insulation is important for keeping power consumption down since it keeps the heat and, therefore, a space heater’s thermostat turns on for reheating less often.

How many solar panels do you need to run a space heater?

With one panel producing 1.8kWh a day, you can power one 1,500W space heater on full settings for 1.2 hours.

Space heaters will run on full power when it’s very cold outside and the insulation can’t hold the heat inside. It’s the worst-case, which we account for.

The table below lists how many hours of full-power heating you can get from a number of solar panels.

In most cases, however, you can increase the amount of space heater hours a solar panel generates by 50% if you assume an average power usage of 1,000W per space heater.

This means, depending you could also get up to 1.8h of space heater usage out of a single solar panel.

The table lists just the minimum amount of power you get out of your solar panels.

To power a space heater on full settings for 24 hours, you need 20 solar panels. On moderate settings, you need 10 solar panels to run a space heater.

That is, however, a conservative estimate. Usually, a space heater does not run on full power, and you don’t need it to run for 24 hours continuously.

Assuming your space heater runs on just 1,000W on average, and you need it to run only 8 hours a day, you need “only” 9 solar panels.

How to run a space heater off solar energy in winter

According to an experiment by “The Solar Nerd” on an average winter day, one solar panel produces around 0.25kWh of energy.

That’s barely anything. It’s about the amount of energy to charge two power banks or boil a few pots of tea. But it’s not enough to keep a room heated.

That’s only a fraction of 15.56% of the solar power available in summertime. To independently heat a space heater off just 0.25kWh per solar panel, you’d need, therefore 20 solar panels * 1.8kWh / 0.25kWh = 144 solar panels.

For powering a space heater off solar panels off-grid in winter, you need 144 solar panels. 

That neither makes sense nor is it cost-effective. Luckily, we have “net metering” to solve this issue.

What is net metering? How does it work?

Net-metering is a virtual storage of the solar energy you produce that can be accessed anytime.

While in the summertime, solar panels could support running a space heater for a few hours, in wintertime, they can’t. 

Ideally, it should be the other way around. Who needs space heaters in summer? 

The solution to this problem is net-metering. Net-metering is the concept to feed your solar panels’ power into your neighborhood’s electric grid. The energy you feed into the grid is compensated and accounted for on your electricity bills.

Effectively, the energy you produce in summer pays for your electricity bill in winter.

You can only power a space heater off solar panels if you use net metering. 

Net metering acts as virtual energy storage. In summer, you feed energy into the grid, in winter, you withdraw it.

In winter, your solar panels don’t really produce any significant amount of power. But you can spend the money net metering generates in wintertime.

Net-metering enables the average solar panel owner to even out seasonal electricity over- and underproduction.

Can off-grid solar panels power an electric space heater?

No. While off-grid solar panels can power a space heater in the sunny seasons, they aren’t able to power an electric space heater during the winter. The lack of sun hours combined with the bad weather makes solar-powered electric off-grid heating impossible.

Does powering a space heater with a solar panel make sense?

If you already have solar panels installed, net metering set up, yes you can run a space heater off your solar panels.

However:

Installing solar panels for heating only is not worth it due to the high installation cost and the high electricity consumption of space heaters.

Especially if your area does not have net metering setting up 144 solar panels just to power a single space heater in the wintertime is pointless.

If you had the money to set up 144 solar panels, you’d probably also not worry about powering space heaters.

What’s the best way to heat off-grid?

The best way to heat without electricity (completely off-grid) is wood. I did an experiment and found it is objectively superior to other heating methods because it has the lowest cost per BTU of heat.

According to the experiment’s results, you get up to 8x more heat when using wood as a heat stove, as compared to solar power, for the same amount of money spent. And this does not even factor in the higher cost of installing solar panels vs. installing a wood stove.

Fun-fact:

Heating with candles is the worst way to heat without electricity. It is 90x more expensive per BTU of heat energy than wood.

Is propane gas good for heating off-grid?

Yes, propane gas is, after wood, the second best way to heat without electricity. When compared with solar power, it is about 2.5x more cost-effective when considering the heat energy (in BTUs) per dollar spent.

So, if you don’t have a wood stove yet, I absolutely recommend getting this Mr. Heater Big Buddy propane heater for off-grid heating.

Both wood and propane are very cost-effective methods for heating independently of an electric grid.

Both propane gas and wood are simple and cheap to store. Especially, when compared to off-grid solar panels, which would require large batteries.

We are not at a point yet, where electric heating beats good old gas heating.

Conclusion

Yes, solar panels can, theoretically, run a space heater. However, installing solar panels just for heating is not worth it due to the high installation cost.

Also, electricity is not a cost-effective way of heating.

Both for on-grid and off-grid heating, wood-burning stoves and propane gas are much more cost-effective heating methods.