How Many Solar Panels Does It Take To Power A Tiny Home?
They take up less space, consume fewer resources to build, and require minimal energy to heat and cool. Most importantly, they're an affordable alternative to big houses and mansions. We're talking, of course, about tiny homes.
You might know them as tiny houses, micro houses, compact abodes, or even shotgun shacks, but whatever you call them, a logical part of the tiny home lifestyle is the addition of solar panels. Economically, they reduce your electric bill — and aside from unforeseen costs that home solar panels sometimes incur — they'll certainly make your tiny residence more eco-friendly. For the folks who like their independence, solar panels can also help keep you off the grid, but be sure to look into tiny home security technology.
Figuring out how many solar panels you need for a regular-sized house is fairly standard, as the growing popularity of the technology has highlighted four main factors to consider. These include your property's sun exposure, how many people live there, your monthly power consumption, and the surface area of your roof. The same details can be analyzed for a tiny home, and to help you figure it all out, we've broken down the necessary calculations into two main variables: your power consumption needs and your solar power potential.
Step 1: How much power does your tiny home need?
A small house that's one-eighth the size of a big house doesn't necessarily consume one-eighth the energy. Many of the same power-hungry appliances, such as phones, televisions, refrigerators, computers, and internet routers, will be needed. However, tiny homes may only have one of each device and will certainly use less energy overall, saving on heating, air conditioning, and lighting.
To calculate how much energy your tiny home will require, it's best to look at your past energy bills, comparing two bills from the summer and winter months to see what heating and air conditioning costs. Mild months that require less climate control will provide the best estimate for your baseline energy needs.
For example, areas with hot summers will see an increase in the July bill compared to April, when air conditioning is less likely to be used. Therefore, the April bill will give you a better idea of your potential consumption in a tiny house, where air conditioning costs significantly less. Once you've totaled all your bills using estimable baselines, divide that by the number of days in the month. You'll need it for the next step.
Alternatively, you could follow the U.S. Department of Energy's guide. It requires some math since you have to add up all the different consumption rates of major appliances. The result is fairly accurate and can be used for the following stage. Here's a tip: To calculate monthly consumption instead of annual consumption, replace 365 with 30 when you reach that step.
Another option at this stage is to skip the math altogether. Popular solar panel guides, such as Bluetti and Ecoflow, use the figure of around 22,000 watt-hours per day as an example of the amount of energy you'll need. You can use this estimate to guide your calculation, though it won't be as accurate as adding up your unique consumption yourself.
Step 2: How much solar power can your tiny home generate?
Once you have an estimate of your daily electricity consumption, you can use your location's solar energy potential to calculate how many panels you'll need to power your tiny home. After all, a solar panel in sunny Tuscon will generate more than one in rainy Seattle.
Fortunately, it's easy to calculate your location's solar energy potential. Numerous tools are available for finding the number of hours of sunlight in your area, and all you need to do is enter your zip code or address. Try Unbound Solar or Google Project Sunroof to find out the amount of sunlight your property receives. Keep in mind, however, that these are optimal sun hours. The idea that cloudy areas can't produce power is a common solar panel myth.
Now that you've worked out the average hours of sun that your tiny house will receive per day, you can calculate how many solar panels you'll need.
Step 3: How many panels will your tiny home require?
With the daily average power consumption and solar potential of your tiny house, you can now calculate how many panels you'll need. Most residential solar panels range from 250 to 400 watts per hour, and some high-efficiency models can generate even more. Figure out which size you'll invest in, or pick a wattage to use as an example for now. You can always enter a different number into the formula if you decide on a different solar panel size later.
Next, multiply the wattage of your solar panel by the daily solar potential you got from Step 2. Then, take your daily average power consumption from Step 1 and divide it by that number.
You can enter the numbers into this formula:
- (Solar panel model's wattage per hour) x (Daily solar potential of your property in hours, from Step 2) = Daily power generation of one panel.
- (Daily power consumption from Step 1) / (Daily power generation of one panel) = Number of solar panels needed.
For example, a 400W panel operating in New Jersey, where the average daily sun exposure is 3.75 hours, will produce 1,500W per day (400Wx3.75h=1,500Wh). So, if your average daily consumption is 22,000W, divide 22,000W by 1,500W. The result is 14.67, which rounds up to 15. Thus, you will need 15 solar panels to produce that energy.
Here's the example plugged into the formula:
- (400W) x (3.75h) = 1,500W
- (22,000W) / (1,500W) = 14.67 ≈ 15