Solar Generator & Power Station Sizing Calculator
Size portable power stations and solar generators. Calculate battery watt-hours (Wh), inverter continuous/surge wattage, appliance runtimes, and solar recharge hours.
| Appliance / Device | Running (W) | Daily Hours | Surge (W) | Energy (Wh) | Action |
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Recommended Power Station Specifications
Solar Generator & Power Station Sizing Calculator - Wh, Watts & Solar Input: Free Solar Generator & Power Station Sizing Calculator tool: size portable power stations and solar generators. Calculate battery watt-hours (Wh).
How to Use the Solar Generator & Power Station Sizing Calculator - Wh, Watts & Solar Input
Add Essential Household or Camping Appliances
Click the appliance presets (fridge, CPAP, router, laptop) or type custom power ratings.
Verify Running Watts and Duty Cycles
Input realistic daily run hours (e.g., a refrigerator compressor runs ~8 hours in a 24-hour cycle).
Select Battery Chemistry & Autonomy Margin
Choose between long-life LiFePO4 (90% DoD) or NMC (80% DoD) and set desired days of reserve storage.
Evaluate Power Station & Solar Input Requirements
Review the required watt-hour (Wh) capacity, inverter wattage, and solar panel recharging timeline.
Engineering Guide: Principles & Formula Details
Sizing a portable power station or "solar generator" demands rigorous separation between electrical capacity (Watt-hours or Amp-hours) and instantaneous power output (continuous and peak surge Watts). While capacity dictates how long devices can operate before the battery depletes, inverter wattage dictates which appliances can physically be turned on without tripping overload protection circuits.
Inductive motor loads—such as compressor-driven refrigerators, portable air conditioners, power tools, and sump pumps—draw high inrush currents during motor startup that can reach three to five times their continuous running wattage. An inverter must sustain this millisecond surge. For example, a 150W refrigerator can spike to 800W for half a second upon startup. Sizing calculators must ensure the pure sine wave inverter rating accommodates simultaneous baseline loads plus the largest single motor surge.
Battery chemistry fundamentally determines usable capacity and long-term lifespan. Traditional lithium nickel manganese cobalt (NMC) batteries offer high energy density but degrade after 500 to 1,000 charge cycles and are typically discharged to 80% Depth of Discharge (DoD). Modern Lithium Iron Phosphate (LiFePO4 / LFP) chemistry provides superior thermal stability, safely supports 90% DoD, and delivers 3,500 to 6,000 cycles before declining to 80% original capacity—translating to 10+ years of daily cycling.
Solar recharging requires matching the power station built-in MPPT (Maximum Power Point Tracking) charge controller specifications. Every solar generator has strict maximum solar input wattage, open-circuit voltage (Voc), and amperage limits (e.g., 60V, 15A, 500W max). In real-world outdoor conditions, solar panels produce roughly 75% to 85% of their rated STC wattage due to sun angle, dust, and temperature heating, requiring realistic solar harvest calculations.
Key Engineering Features & Advantages
Custom Appliance Ledger
Add multiple concurrent devices with specific duty cycles and motor surge ratings.
Surge vs Continuous Analysis
Distinguishes between continuous pure sine wave watts and motor starting surge requirements.
Chemistry Depth of Discharge
Accurately calculates usable energy for LiFePO4 (90% DoD), NMC (80%), and Lead-Acid (50%).
Real-World Solar Recharge
Derates solar panel input by 18% to reflect real-world thermal losses, dust, and MPPT tracking.
Autonomy Buffer
Allows sizing for 1 to 5 days of reserve emergency power during extended grid blackouts.
Market Compatibility
Provides benchmarks matching standard market offerings (Jackery, EcoFlow, Bluetti, Anker).
Frequently Asked Questions
To power a standard full-size refrigerator (which draws ~150W running, spikes to ~800W surge, and runs about 8 hours cumulative per day for ~1,200 Wh/day), you need at least a 1,500 Wh to 2,000 Wh power station with a 1,000W continuous / 2,000W surge inverter, paired with 300W to 400W of solar panels.
Watts (W) measures the rate of electricity consumption at any single instant (like vehicle speed in mph). Watt-hours (Wh) measures the total volume of energy consumed over time (like miles driven). Running a 100W laptop charger for 3 hours consumes 300 Wh of energy.
LiFePO4 (lithium iron phosphate) is chemically non-combustible, does not experience thermal runaway, allows deeper discharge without damage, and lasts 3,500 to 6,000 full cycles (10-15 years) compared to 500-800 cycles for traditional lithium NMC batteries.
Only if the panel voltage (Voc) and current (Amps) fall within your power station solar input specifications. Exceeding the maximum open-circuit voltage rating will permanently destroy the internal MPPT charge controller.