Can a Solar Panel Power a Heat Lamp?

Heat lamps are often used in chicken coops and to keep dogs, cats and cold blooded reptiles warm during cold weather. But can solar panels power a heat lamp? Instead of using electricity, can you harness the power of the sun? Running these lamps on electricity can be costly, so solar may save you some dollars.

A solar panel can charge a heat lamp with 4 hours of sunlight. A solar powered heat lamp is going to last 5 to 6 hours depending on its efficiency.

How Many Solar Panels are Needed to Power a Heat Lamp?

If you don’t want to do any calculating, you can buy a solar powered heat lamp. This kit includes the lamp, solar panel and all the materials needed to set it up. Our top choice for solar heat lamps is the Jior Solar pendant Lights as it is designed for indoors, outdoors, chicken coops, pergolas and other many more.

If you want to build your own solar powered heat lamp or just want to know the numbers, read on.

To calculate, use this: heat lamp wattage = solar panel wattage plus at least 10%.

If you have a 100W heat lamp and want to run it for 5 hours, you need a 100W solar panel and five hours of sunlight. In peak conditions the panel can produce 500W. But solar panel output is not consistent and depending on the weather, you could end up with 460W-480W only.

If you use a 120W solar panel, it can generate up to 600W with 5 sun hours. Even in less than ideal condition the output should be around 500W. Of course if you live in a sunny area with 7 hours of sunlight, getting to 500W is no problem for a 100W solar panel.

Heat Lamp Solar Panel Size Guide

Heat lamps are rated in watts and lumens. Usually both are included in the product specs, but here is a chart that shows you the approximate equivalents.

Lumens	Incandescent	Solar Panel Size	LED	Solar Panel Size
200	15W	20W	2W	5W
400	25W	30W	6W	10W
600	40W	50W	10W	15W
900	60W	75W	16W	20W
1100	75W	100W	20W	25W
1500	100W	125-150W	25W	30W
3000	200W	250W	50W	60W

Keep in mind that these are only approximates. Light efficiency varies per product and in some cases it can be substantial. You can use a lumens to watts converter to get a more precise conversion rate. You should also check if the heat lamp is incandescent or LED, as that affects the watts to lumen equivalent.

You can also use a solar array to power heat lamps, but a battery bank can provide the same power and with better consistency.

Going back to our example, you can connect 3 x 200W solar panels to get 300W within 5 hours, or maybe even 4 solar panels for extra power. That can work, but the problem is solar panels do not produce power in a stable manner.

As long as the sun is out the modules will generate power close to or at peak level. But if a cloud passes by and it becomes overcast, energy production will drop. If it suddenly rains the panels might stop producing altogether. You have to wait for the skies to clear up again.

And here is the thing, most heat lamps are used to keep animals warm during the cold. Meaning the skies will probably be overcast or it rains during early afternoons or most of the day.

You won’t be able to use the full power of your solar panels. With a battery you can charge it and run as long as it is needed. You can use a combination of a solar panel and battery or battery alone, but there should be enough power to keep the heat lamps running.

Do I Need Batteries and a Charge Controller For Heat Lamps?

Heat lamps are used to light up chicken coops and keep livestock or pets warm. n other words you will use it during evenings and cold, rainy weather. Solar panels do not generate electricity at night, so you need a battery to store the power produced during the day for later use at night.

Here is an example. You have a 250W heat lamp and need to run it for 8 hours. You have a 300W solar panel but there is only 5 hours of sun available. Even if the solar panel somehow manages to deliver 300W every hour, that would only be 1500W, short of the 2000W needed. And after 5 hours the panel ceases production.

This is where you need a solar battery , as it allows you to run heat lamps for as long as necessary. 500W is equal to a 12V 41.6ah battery. You can only use a lead acid battery up to 50% so we should double that to 85ah. Charge this battery and you have 500W usable power.

With a 300W solar panel, you can run a heat lamp for 5 hours and then switch to an 85ah battery for the remaining three hours. Just make sure the solar panel is properly installed to avoid draining the battery.

Another option is to run the heat lamp from the battery entirely. In this case you need a 2000W capacity battery, which is 166ah or rounded off to 200ah. Again, you have to double this to 400ah for lead acid because of their 50% discharge rate.

You just charge the battery with your solar panel until it is full. Make sure there is a charge controller before commencing. If your heat lamp is DC powered you can run it right away. If it is AC powered, you need an inverter to convert direct current to alternate current (AC).

The battery size depends on how much solar power you need. You can buy several solar powered heat lamps like the JackyLED Solar Pendant Lights or you can set up a battery bank with big enough to run the lamps all night.

What Inverter Should I Use with Heat Lamps?

If your heat lamp is DC powered you can hook it up directly to the solar panel. If it is AC, you have to use an inverter. Connecting AC powered devices to solar panels is dangerous as the currents are incompatible. With an inverter all the DC power is turned into AC before it reaches the battery bank.

The inverter capacity has to be at least 25% larger than the total wattage required by the heat lamps. For a 250W heat lamp, the inverter has to be 275W or better yet, 300W. Pure sine wave inverters are more effective than modified sine wave, but for heat lamps, modified sine will do fine.

There will be some energy losses during the conversion. The most efficient inverters have a 95% rating, but anything above 85% is acceptable. Modified sine wave inverters are less efficient than pure sine, but they cost less. Since these are just heat lamps there is no reason to splurge on a pure sine wave inverter.

Factors That Affect Solar Heat Lamps

These days you don’t have to hook up a solar panel to a heat lamp, as solar powered heat lamps are available. These are exactly what they sound like, lamps powered by solar panels to produce heat. While PV modules are best known to produce electricity, it is a myth that they cannot generate heat.

There are a lot of solar heat lamps available, so if you want an all in one solution you can try these instead. If you have never purchased any of these before, here are some tips to consider.

Lumen Output

Output for solar heat lamps are often given in lumens. You can use the converter given earlier to find its watt equivalent. Often it is not necessary because the solar panel is already included with the lamp. You just need to charge the lamp and it will run.

The higher the lumens the better obviously. But it also depends on how much heat you need. If you have a chicken coop or animals to keep warm, the heat must be at a specific level, not too hot or too low. Determine what lumens you need and use that as your guide.

You may need to find its watt equivalent if you have to use several heat lamps. A 100 lumen heat lamp is about 20W to 30W. If your chicken coop needs 175W to 200W, you have to figure out its wattage to know how many you need to buy.

Weight

A light heat lamp makes it easy to move around. If you have to use several of these, the weight definitely becomes important. On the other hand, you don’t want the heat lamps to be too light because a strong wind gust could blow it away. Just like with portable solar panels weight matters a lot.

Charge Time

We all want heat lamps to charge as quickly as possible, so this is a critical feature. The best ones have a charge time between 4 to 8 hours. This will also depend on how depleted the lamp is and the running time. The charge and running time usually correlate, that is, the longer the charge time the longer you will be able to use the lamp.

Running Time

Some solar heat lamps can run for 16 hours on an 8 hour charge. Others can do even better. But remember that this is also linked to the lumens, as the hotter the lamp, the shorter the runtime. You have to compute the running time, charge time and lumens to see which combination works best. You also have to determine how many heat lamps you will need.

Waterproof

A waterproof heat lamp is necessary if you are going to use it outside. In many cases you will be using these during the cold or rainy season, so being waterproof is critical. If you don’t figure on a lot of rain or the lamp will be used indoors, then waterproofing will be of secondary importance.

Conclusion

Because heat lamps come in various sizes, there is no one single solar panel size that can run it. You have to match the heat lamp requirement with the solar panel output, and if necessary use a battery bank and charge controller. The good news is there are solar powered heat lamps now available.