Copying the power use of an average U.S. home, about 29.6 kWh a day in 2022 according to the U.S. Energy Information Administration, would take roughly 9 kW of solar panels, about 30 times the 310 W array that runs an example off-grid cabin, so off-grid sizing starts with the load list.
Solar panels for living off the grid are sized from daily watt-hours, plus 20 to 30 % for losses, divided by the peak sun hours of the worst month. A cabin using about 980 Wh a day needs around 310 W of panels. The panel format then follows the surface: rigid for roofs and poles, flexible for vehicles, foldable for sites where the panel follows the sun.
The sections below show how much power off-grid living uses each day, how to turn that load into a panel count for the worst-sun month, and which rigid, flexible or foldable panel fits a cabin, a pole or a van roof. They then match the battery bank and charge controller, compare panel specs in one table and answer common questions. For a fixed home or cabin, LinkSolar's page on off-grid cabin power systems sized for the worst-sun month carries the worked load example used below.
How much power does off-grid living actually use each day?
An off-grid cabin or tiny house typically uses 0.4 to 1.6 kWh a day, a small fraction of the about 29.6 kWh a day an average U.S. home bought in 2022 according to the U.S. Energy Information Administration. Off-grid sizing therefore starts from a device list and daily hours.
A watt-hour (Wh) is one watt of power used for one hour, and 1,000 Wh make one kilowatt-hour (kWh). A 45 W fridge running 10 hours a day uses 450 Wh. Adding every device the same way gives the daily total that the rest of the sizing math depends on.
The live LinkSolar cabin and RV pages, checked September 25, 2026, group off-grid users into these load classes:
- Weekend cabin: Up to about 800 Wh a day for cabin loads such as LED lighting, a 12 V fridge, fans and a pump.
- Tiny house: Around 1.0 to 1.6 kWh a day for full-time living with the same kinds of loads running every day.
- Security-first site: Around 400 to 900 Wh a day for PoE cameras, an LTE router and IR lights, the load profile behind solar power for remote gates, cameras and field sites.
- Weekend van: Usually 100 to 200 W of panel for 12 V lights, fans, phone charging and a small pump.
- Full-time van: Usually 200 to 400 W of panel to carry a 12 V compressor fridge, vent fans, laptops and routers.
The van classes are given in panel watts; the cabin and site classes are given in Wh a day, the figure the next section turns into panel watts.
Heat loads (water heating, cooking and space heating) are what usually break an off-grid power budget. Many off-grid homes move those loads to gas or wood, which typically keeps the daily figure inside the ranges above and the array small. How an off-grid system differs from a grid-tied one is a separate question with its own guide, so this guide stays with loads and panels.
How many solar panels do you need to go off-grid?
The number of solar panels you need to go off-grid equals your daily watt-hours plus 20 to 30 % for losses, divided by the peak sun hours of the worst month, divided by the rated watts of one panel. The first three terms give the array size in watts. The last term turns that array size into a panel count.
According to PVEducation, peak sun hours are the average daily solar insolation in kWh/m², expressed as the number of hours of full 1 kW/m² sunlight. Because peak radiation is 1 kW/m², the daily insolation figure and the peak sun hours figure are the same number.
The five steps below follow the same order as the figure.
- List the loads: Write down each device's power in watts and the hours it runs per day.
- Sum the daily energy: Multiply watts by hours for each device and add the results to get Wh/day.
- Add losses: Raise the total by 20 to 30 % to cover controller, wiring and temperature losses.
- Size the array: Divide the adjusted Wh/day by the peak sun hours of the worst month to get array watts.
- Count the panels: Divide the array watts by the rated watts of one panel and round up.
The worked example on the LinkSolar off-grid cabin page, checked on September 25, 2026, runs the same five steps. A 45 W fridge for 10 hours, 25 W of lights for 6 hours, a 30 W fan for 6 hours and 200 Wh of electronics add up to about 980 Wh a day. With 25 % losses that becomes about 1,225 Wh, and dividing by about 4 worst-month sun hours gives an array of about 310 W.
That array works out to three to four 100 W panels, with the fourth panel taking the count past the 310 W target once the result is rounded up.
An off-grid array is sized for the worst month, not the yearly average. At higher latitudes, winter peak sun hours at the same site are often half of summer's or less, so an array sized on summer sun falls short in the months when the loads still run every day. The cabin page adds that a steeper tilt raises winter harvest and helps shed snow.
A grid-connected house is sized from its utility bill and annual use, which is a separate calculation covered in the guide to panel counts for a grid-connected house.
Which type of solar panel fits your off-grid setup: rigid, flexible or foldable?
Rigid framed solar panels suit fixed off-grid homes and cabins, flexible solar panels suit curved or weight-limited vehicle roofs, and foldable solar panels suit sites where the panel has to follow the sun or pack away. The daily watt-hour figure sets the array size. The surface under the panel sets the format.
Rigid framed panels
A rigid framed solar panel has a glass front and an aluminum frame, and it is built for fixed long-term mounts on tilt brackets or poles. The frame holds the module off the roof on standoffs, so air moves behind the cells and they run cooler than a panel bonded flat. For a cabin or tiny house that stays in one place, this is the standard format.
Flexible panels
A flexible solar panel is a frameless module behind an ETFE front sheet. It takes a gentle curve and weighs roughly a fifth of a glass module of the same output, which suits curved van roofs, boat decks, biminis and trailer skins. The 100 W flexible panel weighs 1.0 kg at 1247 × 418 mm, and the 100 W and 135 W flexible panels with ETFE fronts list their full electrical ratings.
- Curve limit: Folding the panel or forcing a tight radius cracks the cells.
- Heat: Bonded flat with no air gap, a flexible panel runs hotter than a framed panel on standoffs and gives up some output.
- Controller check: Match the open-circuit voltage (Voc) against the charge controller, not only the wattage.
Foldable panels
A foldable solar panel comes in 2-, 3- or 4-fold or suitcase styles, from about 20 W up to 200 W+. Kickstands set common tilt angles such as 25°, 35° and 45°. Outputs include USB-C PD, USB-A, regulated 12 V or 18 V DC, or MC4 leads to an external charge controller.
LinkSolar sources foldable panels built to a fold pattern and output port for fixed product specs. For standard sizes, the range of portable panels that fold away between trips covers camp and backup use.
Many off-grid setups mix formats: a rigid roof array for daily charging plus a foldable panel moved into sun on cloudy runs or at shaded camps.
How should off-grid panels mount on a roof, a ground pole or a vehicle?
Off-grid solar panels should mount where the winter sun reaches them: on a tilted roof bracket, on a ground or pole mount that clears tree shade, or flush on a vehicle roof when the panel travels with you. The mount sets winter harvest, panel temperature and cable length.
For a cabin or tiny house, the LinkSolar off-grid cabin page lists four mounting points.
- Roof Z-brackets: Low-drag Z-brackets hold rigid panels close to a roof whose pitch already faces the sun.
- Tilt mounts: High-angle tilt mounts from 15° to 60° raise winter harvest and help the panels shed snow.
- Pole mounts: A pole or ground mount lifts the array above tree shade when the roof sits under cover.
- DC wiring: Keep DC runs short and fit a fuse or DC breaker within about 18 cm of the battery positive terminal.
Flexible or portable panels are the backup for light roofs and temporary sites.
A campervan or RV roof carries a smaller array sized by travel style. Weekend campers typically fit 100 to 200 W, often one or two flexible roof panels, while full-time vanlife runs around 200 to 400 W to cover a 12 V compressor fridge, vent fans and laptops. The page on RV and campervan arrays by travel style lists the loads behind each range.
- Fastening: At least one fastener per bracket should bite into a roof rib rather than only the thin roof skin.
- Air gap: A small air gap under rigid panels keeps them cooler, and cooler panels hold more of their output.
- Flush bonding: A flexible panel bonded flat with no air gap runs hotter than a framed panel on standoffs and gives up some output.
Where a curved roof leaves no room for standard sizes, flexible panels cut to a curved roof outline can match the footprint and target voltage. For the full sequence on one vehicle, see a full van build with roof mounting and sizing math.
How do you match the battery bank and charge controller to an off-grid array?
An off-grid battery bank is sized from daily watt-hours multiplied by days of autonomy and divided by the usable depth of discharge, and the charge controller is then chosen so its current rating covers the array at battery voltage.
Depth of discharge (DoD) is the share of a battery's capacity used before it is recharged. A LiFePO4 bank is typically run to about 80 % DoD and a lead-acid bank to about 50 %, so the same load needs a larger lead-acid bank. The chemistry guide covers how LiFePO4, lead-acid and sodium-ion banks compare.
The example cabin load with 2 days of autonomy and a LiFePO4 bank works out as follows:
- Stored energy: 980 Wh × 2 days ÷ 0.8 gives about 2,450 Wh of rated capacity.
- Amp-hours at 12 V: 2,450 Wh ÷ 12 V is about 204 Ah, in line with the 200 Ah 12 V bank on the LinkSolar off-grid cabin page.
- Cold sites: Add temperature derating for a bank in an unheated space.
The LinkSolar off-grid cabin page pairs arrays and MPPT controllers by size:
- Around 200 W: A 20 A MPPT controller suits a weekend cabin using up to about 800 Wh a day.
- 300 to 400 W: A 30 to 40 A MPPT controller suits a tiny house using 1.0 to 1.6 kWh a day.
- Small single-load systems: a 10 A MPPT controller for small 12 V systems fits where array current stays under its 10 A rating, and it adds USB-A and USB-C ports.
Before pairing, check array open-circuit voltage, battery voltage and chemistry, charging profile and cable sizing. For small arrays, see the guide on when an MPPT controller earns its place over PWM.
According to the U.S. Department of Energy, inverters convert the DC from PV modules into the AC that most household appliances use, so an off-grid home with AC loads adds an inverter sized to those loads. Series or parallel panel wiring is a separate topic with its own guide.
Specs to compare before you order off-grid solar panels
An off-grid solar panel should be compared on Vmp, Voc, weight, outline and mounting method before wattage, because those figures decide whether it suits your charge controller, your battery voltage and the surface it sits on. Vmp is the voltage at maximum power and Voc is the open-circuit voltage, both rated at standard test conditions. Ask the supplier for the test report that covers the exact panel you order.
According to PVEducation, a typical module with 36 cells in series gives about 17 or 18 V at maximum power and operating temperature, enough to charge a 12 V battery, and that figure sets the rigid row below.
The table compares off-grid panel formats by voltage, weight, surface and best fit.
| Format | Vmp | Voc | Weight / size | Surface | Best off-grid fit |
|---|---|---|---|---|---|
| Rigid framed 36-cell | about 17 to 18 V | varies by wattage | varies by wattage | roof tilt bracket, pole | cabins and tiny houses |
| Flexible 100 W | 18.05 V | 21.63 V | 1.0 kg, 1247 × 418 mm | curved roof, deck | weekend vans and trailers |
| Flexible 135 W | not listed | up to about 30 V | 1.8 to 2.0 kg | wider roof areas | full-time vans; check controller input |
| Foldable | set by design | set by design | about 20 W to 200 W+ class | ground, kickstand | shaded camps, backup |
| Custom | set by cell layout (3 V to 48 V) | to spec | any outline | any | fixed outlines or target voltages |
For a fixed home or cabin, check the row you pick against the cabin mounting options for tilt, pole and roof before you order.
Read the Vmp column against your battery voltage and the Voc column against the maximum input of your charge controller. The Weight / size column shows the load a roof or vehicle has to carry, and the Surface column names the mount each format suits. Varies by wattage means the figure changes with the cell count and panel size, while set by design means it follows the fold pattern and output port chosen for a foldable panel.
FAQ: solar panels for off-grid living
Can solar panels run a whole off-grid house?
Solar panels can run a whole off-grid house when the array is sized from the house's own daily watt-hours rather than from grid-home averages. Many off-grid homes move water heating, cooking and space heating to gas or wood, which keeps a tiny house around 1.0 to 1.6 kWh a day. At that load, the typical starting plan is a 300 to 400 W array with a 30 to 40 A MPPT controller.
How many days of battery storage do I need off-grid?
An off-grid battery bank typically holds 1 to 3 days of autonomy, with more in snowy or overcast regions where dull days come in runs. Multiply daily watt-hours by those days, then divide by the usable depth of discharge of the battery chemistry. A cabin using about 980 Wh a day for 2 days at 80 % usable lands near a 200 Ah bank at 12 V.
Do off-grid solar panels work in winter?
Off-grid solar panels keep charging in winter, with fewer peak sun hours, often half of summer's or less at higher latitudes. Size the array for the worst month and set tilt mounts steeper, since a steeper angle raises winter harvest and helps shed snow. Clear any snow the tilt does not shed, because covered cells stop charging the bank.
Are flexible solar panels good for off-grid living?
Flexible solar panels fit off-grid vans, boats and curved roofs, where an ETFE front and about a fifth of the weight of a glass module of the same output matter most. On a fixed cabin, rigid framed panels on brackets are the stronger choice, because the air gap under them keeps them cooler than a flexible panel bonded flat. Flexible panels also take gentle curves only, and a tight radius cracks the cells.
Next step
Size the array from your worst-month watt-hours, then let the surface choose the format. When no catalog panel fits your roof outline or target voltage, send the outline, daily Wh figure and site location through custom panels built to your outline and voltage to request a quote. LinkSolar returns a buildable spec with cell layout, target Vmp and Imp, lamination and connector.