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Solar Generator Buying Guide: Size It Right in 10 Minutes
A "solar generator" is just a battery (power station) plus solar panels. That simplicity is why most buying mistakes are sizing mistakes — people overbuy capacity and underbuy panel input, or the reverse. Here's the whole process in three steps.
Step 1 · List your loads (be honest)
| Appliance | Typical draw | Hours/day in an outage | Daily Wh |
|---|---|---|---|
| Fridge (mid-size) | 100–200W running | 8 (cycling) | ~1,000–1,600 |
| Wi-Fi router + modem | 10–20W | 24 | ~250–480 |
| Laptop / phone charging | 30–90W | 6 | ~200–500 |
| LED lights (whole room) | 10–30W | 6 | ~60–180 |
| CPAP (no humidifier) | 30–60W | 8 | ~250–480 |
| Microwave | ~1,000–1,500W | 0.25 | ~250–375 |
Ranges are typical field figures — check the nameplate on your own appliances for real numbers.
Step 2 · Do the runtime math once
Daily Wh needed → add 20% inverter losses → divide by 0.85 (usable fraction) → that's your minimum capacity.
Example: 1,500Wh of daily loads × 1.2 = 1,800 → ÷ 0.85 ≈ 2,100Wh minimum for one fully-solar day.
Example: 1,500Wh of daily loads × 1.2 = 1,800 → ÷ 0.85 ≈ 2,100Wh minimum for one fully-solar day.
Translate that to products: a 1kWh unit covers the "fridge + router + lights + phones" day with wall recharging backup; a 2kWh unit covers it comfortably even if the sun doesn't cooperate; 4kWh+ expandable systems are for essential-circuit whole-home duty.
Step 3 · Size the panel input, not just the panels
- Match voltage windows. Panels must stay within the unit's input voltage range — it's in the manual, and it's the #1 returns reason we see.
- Recharge target: to refill ~2kWh in one fair-weather day, plan for ~400–600W of panel input, assuming realistic 3–4 peak sun hours.
- Hybrid input wins. Units that accept wall + solar simultaneously (common on current EcoFlow/Anker/Bluetti flagships) mean clouds are an inconvenience, not a crisis.
The three mistakes that waste money
- Buying capacity without input. A big battery that refills slowly is a bigger problem than a small one that refills fast.
- Ignoring chemistry. For indoor, frequently-cycled units, LFP (LiFePO4) over NMC is worth any modest price difference — cycle life is 3–5x.
- Skipping the surge check. Well pumps, compressors, and some fridges spike hard at startup. If your load list includes motors, leave 2x headroom on inverter rating.
Put it together
- ~1kWh class: EcoFlow DELTA 3 Plus — fastest recovery, our overall pick
- ~2kWh class: Anker SOLIX F2000 (expansion) or Bluetti AC200L (value)
- Camping-only: Jackery Explorer 1000 v2
- DIY/van builds: Renogy components — panels, controllers, batteries sold à la carte