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Because air conditioners use so much power, electric fans have become a popular alternative for solar power users. Watching TV with a cool breeze is nice during the summer, but how many solar panels will you need? We will answer that in this guide along with related questions.
A 250 watt solar panel can power a 52 inch blade ceiling fan and a 42 inch TV for 5 to 6 hours a day, assuming each consumes 90 to 100 watts an hour. But you still need a 50ah battery to store solar energy so you can run the TV and fan when the sun sets.
Calculate Solar Panels For TV and Fan
The formula is the same as when you try to run a TV and a refrigerator on solar power, except this time you will be needing fewer solar panels. You can adjust the numbers depending on the wattage, but the steps are similar.
TV watts + fan watts = number of solar panels needed (plus 10% to 20% for extra power)
An energy efficient 40 to 50 inch TV is 90 to 100 watts. If you pair this with a 100 watt ceiling or tower fan:
100W TV + 100W fan = 200W
You need at least a 200W solar panel like the Newpowa 12V Mono PV Module to run both. Better yet, buy a 250W or 300W panel because solar energy output fluctuates depending on the sun angle, position and presence of clouds.
Now you know what solar panel size to get. How long can the panel run the TV and fan at the same time?
The two appliances consume around 200 watts an hour. A 250 to 300W panel can produce 200 watts or more depending on the weather and available sun. Multiply watt hours by the number of sunlight available to get the runtime.
Total watts x sun hours per day = number of hours you can run the TV and fan
If you live in Tucson or El Paso, expect 6 to 7 hours of sunlight per day. If you are in Seattle or Syracuse, 5 hours of sunlight is what you will get, maybe less depending on the season.
Bottom line: sunlight availability determines how many hours you can use the TV and fan, or any appliance running solely on solar panels. The biggest solar array is no good if the sun does not come out, but a small solar panel can deliver with enough sunlight.
Which Fan is Best For Solar?
There are so many types of fans to choose from, and the good news is most are energy efficient. Compared to air conditioners, fans consume much less power and can run without diverting too much power.
The following is a guideline for fan wattage consumption. The results may vary depending on the manufacturer, so do your own research too. For more informtion, check out our detailed guide on how to run fans on solar power.
- Ceiling fans: 50 to 90 watts. The larger the blades, the more watts required
- Whole house fans: 120 to 600 watts
- Window fans: 35 to 100 watts
- Tower fans: 50 to 100 watts
As you can see there is a wide range for each fan type. This is due to the number of products available. The bigger the blade and motor, the more powerful the fan, but also the more solar power used.
The best fan to use with solar is the one that matches your needs. Since you will be running these with a TV, don’t forget to add the watts when computing the power requirements.
- A ceiling fan can cool a large area and is easy to install. It is less expensive than a whole house fan too.
- A whole house fan, you guessed it, can cool an entire house. It is the most expensive type, but it is still cheaper than buying and running an air conditioner on solar.
- Window fans or box fans are the most energy efficient. They are perfect for one or two people who want a fan nearby while watching TV. They are the least expensive option.
- If a window fan is insufficient, consider a tower fan. They use more watts, but are more powerful, great for beating the summer heat.
Which TV is Best For Solar?
There are two choices for TV, LED and LCD. Do not use CRT or plasma TVs because they use 3 to 4 times more power than LED and LCD. The following is a comparison of LCD and LED TV watt usage. These are estimates only, and the actual figures may be higher or lower depending on the feature set and design.
Display Size (inches) | LED (watts) | LCD (watts) |
---|---|---|
19 | 20 | 22 |
20 | 25 | 25 |
21 | 26 | 30 |
22 | 30 | 40 |
24 | 40 | 50 |
30 | 50 | 60 |
32 | 55 | 70 |
37 | 60 | 80 |
42 | 80-100 | 125 |
50 | 100-150 | 150 |
The watt usage may vary with your own TV because it has been calibrated differently. Today’s TVs give you plenty of options to change the display and that affects the power consumption.
These are all for energy efficient TVs so even a 50 inch model uses less than 200 watts. Pair a 50 inch LED TV with a window fan and you can still run both with a 250W solar panel.
There is more information about solar powered TVs available. For now, suffice to say that these TVs will save you power if you opt for an energy efficient model.
Buying a new TV incurs extra cost, but if you are still stuck with a CRT or plasma, you have to switch to LED or LCD because they are better suited for solar power.
Do You Need a Battery Bank?
You can use a solar panel to run a TV and fan as long as there is sunlight. And there lies the problem. If you want to watch TV at night and keep the fan running, your solar panel cannot help.
That is why you need a battery so you can run the two appliances off it. A 50ah lead acid battery can be paired with a 250W solar panel to run a TV and fan. Or better yet, go with a 100ah AGM battery. We like the Weize 12V battery because it has a long life cycle.
Thee appliances combined consume 200 watts an hour. You have a 250W solar panel that produces 200 watts per hour. With five sunlight hours, that is 1000 watts.
You can run the TV and fan for five hours from let’s say, 10:00 AM to 3:00 PM. A 50ah 12V lead battery is equal to 600 watts (50ah x 12V = 600W). But you can only use 300 watts because lead acid batteries have only 50% energy usability. Keep this in mind if you want to run a floor fan on a battery for instance.
But even so 300 watts is enough for the two of them. If the battery is fully charged, you can use it for another five hours before the level drops to 50%. You can keep recharging the battery and use with the solar panel for both appliances.
A 50ah battery is the minimum size you will need. You can always use a larger battery bank to power a larger appliances. With a powerful solar panel and battery, you will be able to connect movie players or gaming consoles to the TV.
Do You Need an Inverter for a Solar TV and Fan?
Most TVs use direct current (DC), so you do not need an inverter. Many TVs though connect to a 120V AC socket but actually use DC and / or AC when running. It is best to check your TV set to find out what it uses. Contact a solar panel installer if you are not sure.
Fans come in AC and DC models, but DC units are more energy efficient. Some DC fans use 70% less watts than AC, so this is definitely what you should look for in a solar power installation. To put it another way, a 100W AC fan is equal to a 25W DC fan, and for solar panels that is huge.
Bottom line, you do not need an inverter to run a fan and TV from a solar panel. You can charge and run the appliances from the battery bank or the solar panel directly. Do make sure you have a charge controller to keep the battery running smoothly.
Conclusion
With energy efficient TVs and fans widely available, you do not have to allocate so many solar panels to run them. You use electric fans mostly during summer, which also happens to be peak solar power production. Even better, a small battery will suffice.
I am an advocate of solar power. Through portablesolarexpert.com I want to share with all of you what I have learned and cotinue to learn about renewable energy.