December 15, 2024 · KYRAX journal
Tiny House Solar Panels: Cost and Sizing
What a tiny house solar system costs, how to size one from your own daily kWh, and why the winter figure matters more than the annual average.
Updated September 4, 2026: a cost summary up front, a worked example for sizing an array from your own consumption, and why the December figure is the one that decides the system.
Harnessing the Sun for Tiny Living
Solar power and tiny homes are a natural pairing. A well-designed solar system provides energy independence and eliminates monthly electric bills. Here’s what you need to know about implementing solar in your tiny home.
What it costs, in one paragraph
A complete 3 kW system for a tiny home runs roughly $10,900 to $23,300 installed. The battery bank is the single largest line at $5,000 to $12,000 and it is the item that moves the total most, because capacity is what buys you the ability to ride through days without sun. Panels are comparatively cheap. The full component breakdown is further down, and the sizing method below is what tells you which end of that range you are at.
Understanding Your Energy Needs
Before sizing your system, calculate your daily energy consumption:
Typical Tiny Home Loads:
- LED lighting: 50-100 Wh/day
- Refrigerator: 1,000-1,500 Wh/day
- Mini-split HVAC: 2,000-5,000 Wh/day (climate dependent)
- Electronics (laptop, phone, TV): 500-1,000 Wh/day
- Water pump: 100-200 Wh/day
- Miscellaneous: 500-1,000 Wh/day
Average total: 4,000-9,000 Wh (4-9 kWh) per day
Turning that into an array size
The arithmetic is short. Take your daily consumption in kilowatt-hours, divide by the usable sun hours at your site, then divide again by a system derate of about 0.75 to 0.8 to account for inverter losses, wiring, panel temperature and dust. What comes out is the array size in kilowatts.
Suppose the home uses 6 kWh a day and the site averages four usable sun hours: 6 ÷ 4 ÷ 0.78 gives about 1.9 kW. Run the same home somewhere with two usable sun hours and the same calculation gives about 3.8 kW. Nothing about the house changed. Only the site did.
Battery capacity works the same way. Multiply daily consumption by the number of days you want to run without sun, then divide by the usable depth of discharge of your chemistry. Six kilowatt-hours a day across two days at 80 percent usable depth comes to about 15 kWh, which is why the 10-20 kWh range below covers most builds.
The 3kW System: The Sweet Spot
A 3kW system is ideal for most tiny homes because:
- Generates 10-15 kWh/day in good conditions
- Fits on most tiny home roofs (8-12 panels)
- Provides buffer for cloudy days
- Reasonable cost and complexity
Size it for December, not for the year
The single most common way a tiny home solar system disappoints its owner is being sized on an annual average. Sun hours are lowest in winter and heating and lighting loads are highest in winter, so the two curves move against each other and the shortfall lands in the same weeks every year. A system that is comfortable in July and short in January was sized on the wrong number.
Use the figure for your own location rather than a national one. Natural Resources Canada publishes photovoltaic potential data for Canadian sites, and NREL’s PVWatts calculator covers US locations. Both give you monthly figures, which is the point: the December row is what you size against, and the gap between it and the June row is what tells you whether you need a generator, a larger bank, or a propane load shift.
This is also the question that decides format. An off-grid build in a cold climate is mostly an envelope problem before it is a solar problem, because every watt the building loses is a watt the array has to replace in the season it produces least.
System Components
Solar Panels
- 8-10 panels at 300-400W each
- Monocrystalline for best efficiency
- Roof-mount or ground-mount options
- Expected lifespan: 25-30 years
Charge Controller
- MPPT (Maximum Power Point Tracking) recommended
- 60A controller for 3kW system
- Maximizes energy harvest
- Protects batteries from overcharge
Battery Bank
- Lithium (LiFePO4): Higher cost, longer life, lighter weight
- Lead-acid (AGM): Lower cost, proven technology, heavier
- Capacity: 10-20 kWh recommended for 1-2 days autonomy
- Typical cost: $5,000-15,000
Inverter
- Pure sine wave for sensitive electronics
- 3,000W continuous, 6,000W surge recommended
- Split-phase capability if needed
- Integrated charge controller options available
Installation Considerations
Roof Mounting
- Assess structural capacity for panel weight
- Consider aerodynamics (trailer homes)
- Tilt angle optimization for your latitude
- Allow for proper ventilation under panels
Ground Mounting
- Requires additional property space
- Easier access for cleaning and maintenance
- Can optimize tilt and orientation
- May require permits in some areas
System Costs
Component Breakdown (3kW system):
- Panels: $2,000-3,500
- Charge controller: $400-800
- Battery bank: $5,000-12,000
- Inverter: $1,500-3,000
- Wiring, mounting, installation: $2,000-4,000
Total: $10,900-23,300
Payback period: 5-10 years depending on local electricity rates
Maximizing Efficiency
- Use efficient appliances: Propane for cooking and heating reduces electrical load
- LED everything: Lighting efficiency makes a significant difference
- Time heavy loads: Run washing machine and high-draw items during peak sun
- Monitor consumption: Real-time monitoring helps identify waste
- Maintain panels: Clean panels produce more power
How KYRAX handles solar
Solar on a KYRAX build is specified before construction starts rather than fitted afterwards. That means the array, the battery bank, the inverter and any backup source are sized together against your site and your actual loads, and the electrical layout is drawn to match. It is the same approach described on the off-grid models page, where the rest of the systems — water collection, filtration and toilet choice — are set the same way.
We do not publish a fixed solar package price, because the honest answer depends on the site. A home on an open southern slope and a home under trees on a north-facing lot need different systems and should not be quoted the same number. Bring your consumption estimate and your location to a consultation and the sizing gets done against real figures.
Worth reading alongside this: our guide to on-grid vs off-grid living for whether to cut the connection at all, and composting toilets vs standard plumbing for the waste side of the same decision. If you have not settled where the home is going yet, check what your lot allows first — zoning decides more about an off-grid build than the array does, and what states allow off-grid living explains which rules actually bind.
Common questions
How many solar panels does a tiny house need?
Most tiny homes land on eight to ten panels of 300 to 400 watts, which is roughly a 3 kW array. That is a starting point, not an answer: the number falls out of your daily consumption divided by the usable sun hours at your site, then divided again by a system derate for inverter, wiring, temperature and soiling losses. A home running a mini-split in a cold climate and a home running lights and a laptop do not need the same array.
How much do solar panels cost for a tiny house?
Budget roughly $10,900 to $23,300 for a complete 3 kW system installed. The battery bank is the largest single line at $5,000 to $12,000, followed by installation and wiring at $2,000 to $4,000, panels at $2,000 to $3,500, the inverter at $1,500 to $3,000, and the charge controller at $400 to $800. Payback runs five to ten years depending on local electricity rates.
How much power does a tiny house use per day?
Typically four to nine kilowatt-hours a day. A mini-split is usually the largest load at 2,000 to 5,000 Wh, then the refrigerator at 1,000 to 1,500 Wh, electronics at 500 to 1,000 Wh, the water pump at 100 to 200 Wh, and LED lighting at only 50 to 100 Wh. Heating and cooling decide the total, which is why the same house needs a different system in a different climate.
Can a tiny house run entirely on solar?
Yes, if the array and battery bank are sized for your worst month rather than your average one, and if the loads are chosen to suit. Moving cooking and water heating to propane takes the two largest resistive loads off the array entirely. The homes that struggle are the ones sized on an annual average and then asked to carry electric heat in December.
How big a battery does a tiny house need?
Ten to twenty kilowatt-hours covers one to two days of autonomy for most tiny homes. Work it out as your daily consumption multiplied by the days you want to ride through without sun, divided by the usable depth of discharge of the chemistry you choose. Lithium iron phosphate costs more up front and lasts longer; sealed lead-acid costs less and weighs more, which matters on a trailer.
Talk to us
If you have a project in mind, or a question this post does not answer, email info@kyraxhomes.com, call +1 888 337-1413, or reach us through the contact page. To talk through a specific project, book a consultation.
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