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How Big a Solar Generator Do You Need? (2026)

Solar generators are sold by battery capacity, from around 300Wh up to 2,000Wh and beyond, and it's easy to either overspend on capacity you'll never use or underbuy and get caught short in an outage. Here's how to match the size to what you actually need to power.

Updated July 2026·6 min read·Affiliate disclosure

Two numbers that actually matter

Capacity (Wh) — the tank

Total stored energy. Determines how long the unit lasts before it needs a recharge — more Wh means longer runtime for the same devices.

Continuous output (W) — the tap

How much power it can deliver at once. A device that draws more watts than the unit's rated output simply won't run, no matter how much capacity is left in the tank.

Do the math for your own setup

Add up the wattage of everything you'd want running at once, multiply by the hours you want to cover, then divide by about 85% to account for inverter and cabling losses. A 60W mini fridge plus a 10W router for a 24-hour outage is (60 + 10) × 24 = 1,680Wh of demand — divide by 0.85 and you land around 1,975Wh, which puts you in our ~1,000Wh–2,000Wh range depending on how much margin you want.

Pick your tier

~300Wh — One person, essentials only

Jackery Explorer 300 Plus (288Wh Battery)

Phone and laptop charging, a router, and a lantern or lights through a multi-day outage. Not enough for a fridge or anything that heats.

Check price ($299) ↗View Jackery panel ↗

~1,000Wh — A household covering the real essentials

Jackery Explorer 1000 v2 (1kWh Battery)

A mini fridge, router, lights, a CPAP overnight, and laptop/phone charging for a full day between recharges. The size we recommend to most first-time buyers.

Check price ($449) ↗View Jackery panel ↗

~2,000Wh+ — Whole-apartment backup or multi-day outages

Jackery Explorer 2000 v2 (2.04kWh Battery)

A full-size fridge, microwave, space heater, and lights running for a full day, or smaller loads stretched across a multi-day outage.

Check price ($749) ↗View Jackery panel ↗

Frequently Asked Questions

What's the difference between capacity (Wh) and output (W)?
Capacity, measured in watt-hours (Wh), is how much total energy the battery stores — think of it as the size of the tank. Continuous output, measured in watts (W), is how much power it can deliver at once — the size of the tap. A 2,000Wh unit with only 300W of output can't run a 1,000W microwave even though it has plenty of stored energy, so check both numbers against your actual devices.
How do I estimate the watt-hours I need?
Add up the wattage of everything you want to run at once, multiply by how many hours you want to run it, then divide by about 0.85 to account for inverter and cabling losses. Example: a 60W mini fridge and a 10W router for 24 hours is (60 + 10) × 24 = 1,680Wh of demand, so divide by 0.85 to get roughly 1,975Wh of battery capacity needed — call it our 2,000Wh tier.
Should I buy bigger than I think I need?
A little headroom is worth it — battery capacity degrades slowly over years of use, and buying for your worst realistic outage (not your average one) means you're not caught short during the outage that actually matters. That said, doubling up on our 300Wh tier is usually cheaper and lighter than jumping straight to 2,000Wh if you mainly need portability.
Does the solar panel size matter for recharging speed, not just running devices?
Yes — panel wattage determines recharge time, independent of battery capacity. A 100W panel takes roughly 4–5 hours of direct sun to refill a 300Wh unit but 20+ hours for a 2,000Wh unit. If you're sizing up to a larger battery, consider a second panel or a higher-wattage one to keep recharge times reasonable.

Not the same as plug-in solar

These units don't connect to your home's wiring, so sizing one has nothing to do with your state's plug-in solar law — see our solar backup power guide for the full distinction and device-by-device runtime charts.

Further reading