Solar-Powered Tiny Houses: A Complete Guide
8 - Minute Read
Aug 24, 2022
It’s arguable that there has never been greater homeowner curiosity and consideration for installing a home solar system. Likewise, genuine interest in the so-called “tiny house” is also peaking. Currently both industries are being buttressed by similar market forces as the technologies that support them continue to elevate efficiencies while lowering costs. Naturally, then, dreams of a solar-powered tiny house are now coming true for more and more homeowners. We’ll investigate what is behind the market forces, technologies driving this trend and why a modern solar energy application can be an excellent fit for tiny house living.
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Why Power A Tiny House With Solar Energy?
Tiny home ownership allows residents to own their own home on a budget, often on a piece of real estate where they could not afford a larger home. The potential savings tiny house living offers homeowners can span across all budget categories, including energy. Using solar power to run a tiny home offers even greater potential for savings on energy costs.
Of course, installing a solar energy system is expensive. While it may take several years for savings on electricity to cover the initial outlay for solar panels, once it is paid off electricity can be nearly free, though you should still expect to pay service, distribution and transmission charges while still connected to the grid. And some could qualify for solar rebates or incentives from federal and state agencies or even their utility company – which could reduce the initial investment.
Aside from reducing energy costs, some tiny house owners are also strongly motivated by environmental concerns. They like the fact that their smaller home requires fewer resources to build and takes up less space. And some tiny houses are built at least in part with recycled materials. It’s likely that people with this mindset would welcome the idea of powering their home mostly or entirely from clean, renewable solar energy.
And finally, many tiny homes are designed to be mobile, giving their owners the freedom to keep their house while changing their surroundings completely. Most tiny houses can be placed on a trailer and moved relatively easily – in fact, some are actually built on a flatbed trailer with wheels. Theoretically, if it has an integrated solar power system, such a home can be moved anywhere. And depending on permitting requirements, tiny homes can typically be connected to their local power grid or use other energy sources such as a propane tank with minimal effort.
Considerations For Powering A Tiny Home With Solar Power
The economics of living in a solar-powered tiny house — including the initial cost of solar panels and other hardware, having the system installed, and realizing savings on electricity on a monthly and yearly basis — are all influenced by a number of factors. Like tiny homes themselves, each solar energy system is different. Before one is chosen, a full assessment of the energy requirements of the home as well as the type, size, and cost of what is needed should be completed.
It’s difficult to pinpoint an exact kilowatt-hour (kWh) number for tiny homes because of several influencing factors. Factors such as local weather, square footage, construction materials, and exactly which functions of the house will require electricity all weigh heavily on the answer. Points to consider include:
- Heating: In places that experience a longer, colder winter such as the northern U.S., home heating is a significant expense for 6 or more months a year. This may require a larger solar array. Fortunately, in many places a home furnace can run on natural gas or propane. People with a tiny house in such a climate would be wise to consider this option since it preserves solar electricity for other functions that can only run on electricity.
- Air conditioning (cooling): In warmer climates, like the southern United States, air conditioning (AC) units also consume a tremendous amount of power. A tiny house located in a hot, sunny location such as Arizona can benefit from ample exposure to the sun, but it also will consume a lot of electricity for AC during months when the temperature can routinely surpass 100 degrees Fahrenheit. Unfortunately, there are few effective alternative power sources for air conditioning unless you forgo AC altogether — in such a climate the solar energy system will have to be large enough to cover AC usage.
- Insulation: A well-insulated tiny house will consume less electricity whether it is located in a heating-dependent or AC-dependent climate.
- Appliances: Some of the most common appliances that people see as essential are dependent on electricity exclusively for power. Washing machines, refrigerator/freezers, televisions, computers, cell phones, toaster ovens, and microwave ovens rely almost exclusively on electric power. Other appliances, such as clothes dryers, water heaters, and ovens/ranges can run on natural gas, which should be strongly considered for a solar-powered tiny house when that option is available. Where weather permits, an outdoor propane-powered grill for cooking can also reduce the need for electricity.
- Lighting: Lightbulbs also require electricity. In recent years, the development of less expensive LED bulbs, which use far less power than traditional incandescent bulbs, has brought down the cost of lighting a home. Of course, candles, kerosene lanterns, and battery-powered lanterns can also reduce reliance on electricity for light, even if they are less effective and less convenient.
The Differences Between Grid-Tied And Off-Grid Systems
The vast, interconnected, engineered electrical system that brings power to the homes and businesses in a community is known as the “grid.” The local utility company monitors the amount of power consumed by each house and bills monthly depending on usage, charging a dollar amount per unit known as a kilowatt-hour. A solar-powered tiny house, or any house for that matter, can be set up to operate completely independently of the grid (off-grid) or in concert with the grid (grid-tied). There are advantages and disadvantages to each, particularly as to how each effects the operation of a tiny house.
Off-Grid Solar-Powered Tiny House
An off-grid tiny house generates all of the electric power it needs from its solar system or other energy alternatives. It can be significantly more expensive to install an off-grid system than a grid-tied system because, in addition to its solar panels, it must also have batteries to store power for use at night or on cloudy days. These batteries can be very expensive — costing anywhere between $10,000 and $20,000 for purchase and installation. The most significant advantage of such a system is that it is not dependent on the grid at all and therefore can supply power during an outage.
A downside is that during prolonged cloudy periods or higher-than-normal power use, the batteries can become depleted leaving the system incapable of producing electricity as fast as its being consumed.
Another thing to consider is that a tiny house will likely not have enough square footage on its roof to support all of the solar panels needed to adequately power the home. In these cases, an array of solar panels must be erected near the house. If a homeowner wanted to move their tiny house to another location, the panel array would have to be moved as well.
Grid-Tied Solar-Powered Tiny House
A grid-tied solar system is actually connected to the utility company’s network. It generates electricity the same way an off-grid system does, but it does not require an expensive battery for storing power since it simply draws power from the grid when it is unable to produce enough to supply the home. Through a billing system known as net metering, homeowners can sell solar energy back to the grid when it is in surplus and also buy from the grid when there is a deficit. Check with your local utility company to see whether they offer net metering.
The principal disadvantage is that when there is an outage on the grid, the system shuts down and the home is without power. Some solar customers, however, will choose to add a backup battery for storage while maintaining a grid-tied system under normal conditions.
The Number Of Solar Panels You’ll Need
Determining the number of standard 3-foot x 5-foot solar panels needed to fully power a home requires consideration of so many factors that it really should be set by a professional solar installer. Most estimates place the number at between 20 and 40 panels for a 2,000 square foot home — not an exacting estimate but with widely varying climates, sunlight exposure, electrical power requirements, and panel quality, a realistic one. Depending on the annual wattage required and the number of watts each panel can produce (a low wattage panel might produce 150 watts, while a more expensive, high-wattage panel could produce 370), a technician can arrive at the best number of panels for the home.
Panel placement is also an important consideration. Typically panels are placed on the roof, but in some cases — particularly for a tiny house — the roof is not big enough to handle all the panels for the system. Or perhaps the house is shaded for much of the day, reducing power generation. In such cases some or all of the panels would need to be ground mounted or pole mounted in a sunny place somewhat near the house.
Get An Estimate
Efficiency and cost depend on the panels chosen for the array. but in 2022 most home solar panels produce between 300 and 400 watts of power per hour in direct sunshine. An array of nine 330-watt solar panels, then, could produce enough power to support a 3-kWh solar system, which could cover the energy use of a tiny home, if we consider that the average tiny house uses about 3 – 4kWh electricity.
One way that the cost of a solar energy system is determined is by dollars/watt. According to Energysage, in 2022 the average cost of a home solar system, installed, was $2.77/watt after accounting for installation, ongoing maintenance, and any qualifying credits. So, for this example 3 kWh system the initial investment would be approximately $8,310. Of course, that number can vary widely depending on weather, energy needs, etc., spanning between $2,000 and $10,000 or beyond for some systems.
Should You DIY Your Solar Tiny Home?
The installation of an expensive, critically important home solar energy system is almost always best left to a professional solar installer. Certainly, there are some very experienced DIY individuals who can handle the job. While aspects of the project are relatively simple and involve drilling holes and installing lag bolts to mount the panels, other tasks are more complex.
Remember that professional solar installers do more than just install the panels. They are skilled at determining the size of the system and designing it for maximum solar capture. They are aware of available rebates and tax credits and know how to work with the local building authority on obtaining permits and inspections. Finally, they will have an accredited electrician on staff to make sure the system hooks up properly and safely.
Experienced DIY builders who still wish to go it alone should be aware of PVWatts and Build it Solar, two organizations that supply information and advice on DIY solar projects.
The Bottom Line: Solar Power And Tiny Homes Can Go Hand In Hand
As home solar energy systems become both more affordable and efficient, they are increasingly becoming an option for tiny house living. Many people decide to build a tiny house because they wish to live in a remote location that might not have easy access to a power grid. They are often adventurous individuals who enjoy the challenge of designing and living a clean, sustainable off-grid lifestyle. They also aim to live on a budget, and once a solar energy system pays for itself (usually within 5 to 10 years), monthly electric bills can decrease significantly.
Before investing time and finances toward designing and building their dream solar-powered tiny house, however, homeowners would be wise to make a thorough assessment of what kind of electrical power needs their home will have in light of its location and functionality. To reduce the risk of outages due to loss of backup battery power, consider the use of alternative fuels such as propane for some essential functions. Home heating, by far the most expensive essential function for a tiny house in a cold climate, can be run on propane that is readily available even in remote areas of the U.S. This leaves more electric power for appliances, lighting, and air conditioning, which run almost exclusively on electricity.