How Long Can a Solar Generator Power a House?

The sales pitch sounds great: a solar generator that powers your whole house indefinitely. The reality is more nuanced — and understanding it is the difference between a system that meets your needs and one that leaves you in the dark at 2 a.m. How long a solar generator can power your house depends on three factors: the battery capacity, what you’re running, and how much sun you’re getting to recharge. Here’s the honest breakdown for Southern homeowners in 2026.

What Actually Drains a Solar Generator Battery?

Not all appliances are created equal when it comes to power draw. Your battery lasts dramatically longer if you understand which loads matter most:

High-drain appliances (use sparingly during outages):

• Central air conditioning: 3,000–5,000W running, 6,000–10,000W startup surge
• Electric water heater: 4,000–5,500W
• Electric dryer: 5,000–6,000W
• Electric range / oven: 2,000–5,000W

Medium-drain appliances (manageable):

• Window AC unit (8,000 BTU): 700–900W
• Refrigerator: 100–400W average (runs in cycles)
• Sump pump: 800–1,500W (runs intermittently)
• Microwave: 900–1,200W (short bursts)

Low-drain essentials:

• LED lighting (whole home): 100–200W
• Phone and device chargers: 20–60W
• Internet router: 10–20W
• Medical devices (CPAP, etc.): 30–60W

How Long Does a Solar Generator Last on One Charge?

Let’s run real numbers for the most popular portable solar generators among Southern homeowners in 2026:

EcoFlow DELTA 2 (1,024 Wh battery):

• Essential load only (fridge + lights + devices): 8–12 hours
• Add a window AC unit: 1–2 hours
• Medical devices overnight: 12–18 hours

EcoFlow DELTA Pro (3,600 Wh battery):

• Essential load (fridge + lights + devices): 24–36 hours
• Essential load + window AC cycling: 8–14 hours
• Central AC running constantly: 1–2 hours (not practical)

EcoFlow DELTA Pro Ultra (7,200 Wh single battery, expandable to 21.6 kWh):

• Essential home loads: 48–72 hours
• Essential loads + window AC: 18–28 hours
• Most of a typical home’s loads: 8–16 hours

The EcoFlow DELTA Pro Ultra is the current standard for whole-home backup among solar generator buyers — it’s what most families in Georgia and Tennessee are choosing for serious backup power in 2026.

How Does Solar Recharging Change the Equation?

This is the key question — because with adequate solar input, a generator battery becomes a buffer rather than a countdown clock.

In the South, expect 4–6 peak sun hours per day during summer, 2.5–4 hours in winter. Here’s what that means for recharging:

EcoFlow DELTA Pro with 2 x 400W panels (800W input):

• Summer day recharge: 3,600–4,800 Wh added (can fully recharge the battery)
• Winter/cloudy day: 1,000–2,000 Wh added (partial recharge)

Practical implication: with a DELTA Pro and 4–6 solar panels, most Southern families can run essential loads indefinitely during daylight-hour outages in summer. The system recharges faster than it drains under normal essential-load use.

During multi-day cloudy weather (common in winter ice storms), the battery depletes over 2–3 days without significant recharge. That’s when Bluetti’s expandable systems shine — add more battery capacity as a buffer. The Bluetti AC200L allows adding 200Ah expansion batteries, extending runtime significantly during low-sun periods.

Can a Solar Generator Run Central Air Conditioning?

Technically yes, but practically it’s a losing battle for most systems. A 3-ton central AC (36,000 BTU) draws 3,000–4,500W continuously and spikes to 12,000W+ on startup. Running it off a single solar generator battery is extremely inefficient and will drain even a DELTA Pro Ultra in a few hours.

The realistic alternatives for Southern homeowners during summer outages:

• Window AC unit (8,000 BTU) in the bedroom: 700–900W, runs 8–14 hours on a DELTA Pro
• Portable AC unit: 1,000–1,500W, manageable runtime with a large battery
• Whole-home battery system (multiple units): 3–4 DELTA Pro Ultra batteries with 8+ solar panels can handle central AC cycling

For most families, the practical answer is: run a window AC in one room, keep the fridge running, maintain phone and internet, and endure the inconvenience. That’s realistic for a $1,500–$3,500 investment. True central-AC backup requires either a propane/gas generator or a $20,000+ whole-home battery system.

How to Size a Solar Generator for Your Needs

A simple sizing process: list the appliances you must run during an outage, add up their wattages, and multiply by the hours you want to run them. That’s your minimum battery capacity needed. Add 25% for inefficiency losses. Then calculate your solar input to see if you’ll recharge fast enough to sustain it.

For most Southern homeowners, a 3,600–7,200 Wh battery with 800–1,600W of solar panels hits the sweet spot: it handles essential loads through a typical 1–3 day outage with comfortable recharging headroom.

Bottom Line

A well-sized solar generator with solar panels can power your home’s essentials indefinitely during summer outages. For essential loads (fridge, lights, devices, one window AC), expect 12–36 hours per charge depending on battery size, with full daily recharging possible when the sun shines. For whole-home loads including central AC and electric water heating, you need either a large multi-battery system or a conventional generator. For most Southern families, a mid-range solar generator covers the outages that actually happen — and that’s the right investment in 2026.