Quick answer: start with 1,900 W of solar
An electric dryer is one of the hardest household loads for solar, not because of its daily energy, about 4,200 Wh for one load or roughly 1,900 W of solar, but because it needs about 7,000 W of continuous inverter capacity at 240 V for most of an hour. A clothesline, a heat-pump dryer, or a gas dryer changes the system far more than more panels do.
Planning result
At 200 W per module, the array target is 10 panels. That count assumes four peak-sun-hours, 75% end-to-end solar yield, 90% conversion efficiency, and a 20% planning margin. In winter, laundry often moves to the dryer just as sun-hours fall; in summer a clothesline does most of the work.
How a clothes dryer actually uses power
Planning case: a standard vented 240 V electric clothes dryer running one load a day: a heating element of several kilowatts plus the drum and fan motor, about 5,600 W combined while the element is on, for 1 hour at 75% element on-time. GE rates its full-size electric dryers at 5,600 W (24 A at 240 V) on a 30 A circuit.
The element cycles on a thermostat to hold the exhaust temperature while the motor turns the drum and blower continuously. Wet clothes keep the element on almost constantly at the start of a cycle; as they dry, it cycles off more often. Moisture-sensing cycles end sooner than a fixed timer and save energy.
Load calculation from running watts and duty cycle
The appliance-class estimate is 5,600 W running for 1 h/day at a 75% duty cycle, an average of about 4,200 W across those hours:
Then losses and reserve raise the energy the system must collect to about 5,600 Wh/day.
Typical manufacturer nameplate/manual range for the clothes dryer class, triangulated with GE Appliances: Electric dryer wattage, amperage, and electrical rating and ENERGY STAR: Clothes Dryers, then reduced to a conservative planning midpoint; this is not a product specification. Verify the exact unit's nameplate and manual before sizing.
Use a whole-circuit energy monitor on the dryer breaker and record a typical load. A 240 V dryer cannot use a plug-in meter.
Solar and battery sizing table
| Design item | Planning value | Basis |
|---|---|---|
| Appliance energy | 4,200 Wh/day | Running W × hours × duty cycle |
| Solar collection target | 1,900 W | 4 peak-sun-hours, 75% yield, 20% margin |
| 200 W panel count | 10 | Rounded up; real modules must satisfy controller voltage/current limits |
| One-day battery allowance | 7,000 Wh | 90% conversion efficiency, 80% LiFePO4 usable fraction, 20% margin |
| 12.8 V LiFePO4 equivalent | 550 Ah | Nominal planning conversion |
| 25.6 V LiFePO4 equivalent | 275 Ah | Nominal planning conversion |
Run the dryer in the middle of a sunny day so the array supplies most of it; the battery then only covers clouds and the motor start.
Build the closest passing wiring-diagram preset
The Clothes Dryer Planning System preset is an engine-passing starting point whose array, battery bank, continuous inverter rating, and surge rating each meet or exceed this page's stated planning allowances. Adjust it only from measured load data and verified equipment limits.
Inverter and startup current
Use at least 7,000 W continuous with 7,000 W surge for this planning case. The drum motor starts first with a short surge, then the element adds several kilowatts of steady load; the element is the part the inverter must carry continuously.
Because this load draws its full power for long stretches rather than for a moment, the battery-to-inverter cable carries heavy current continuously. A run that is too long or too small wastes energy as heat and can push the inverter to its low-voltage cutoff late in the day, even with energy left in the battery, so use the diagram machine's real run length and keep every fuse within the equipment and conductor limits. The 6,200 W peak estimate is a planning figure, not the manual's rating.
The common mistake
Ways to cut the load
- Use a clothesline or drying rack whenever the weather allows.
- Choose a heat-pump dryer if you need a dryer: full-size and compact heat-pump models run on roughly 830 to 900 W, and ENERGY STAR estimates they use around 70% less energy than a conventional dryer.
- Spin loads at the washer's highest speed first so less water reaches the dryer.
- Clean the lint screen and the vent so each load finishes sooner.
What to verify before buying equipment
- The exact running watts, startup current, voltage, frequency, and required circuit from the appliance label and manual.
- Actual watt-hours over a representative day; seasonal heating or cooling loads need a design-day measurement.
- Local peak-sun-hours for the worst operating season, plus shade and array orientation.
- Controller maximum input voltage at the coldest expected temperature and maximum output current.
- Battery discharge current, series/parallel permission, terminal torque, low-temperature controls, and overcurrent protection.
- Conductor ampacity, voltage drop, terminal temperature ratings, disconnecting means, grounding, local amendments, and inspection requirements.
For a whole-system load list, use the load and appliance calculator. For the system context around this appliance, continue to the Load and appliance calculator.
Frequently asked questions
How much solar do I need for a clothes dryer?
For the planning case on this page (a 240 V electric dryer running one load a day), allow about 1,900 watts of solar at four peak-sun-hours per day. That covers an estimated 4,200 Wh daily load plus conversion, temperature, and recharge margin. A heat-pump dryer or a clothesline shrinks this far more than adding panels.
What size inverter should I use for a clothes dryer?
Plan on at least 7,000 W continuous and 7,000 W surge. Most electric dryers need 240 V, so confirm the inverter output configuration as well as its continuous rating.
What battery size keeps a clothes dryer running for one day?
The one-day planning allowance is about 7,000 Wh nominal usable design capacity, roughly 550 Ah at 12.8 V or 275 Ah at 25.6 V for LiFePO4. Drying in the middle of a sunny day lets the array carry most of the load directly.