How Much Power Does A 5 kW Solar System Produce Per Day, Month, And Year? (2026)

I built a 6 kW grid-tie array on my own house in 2024 — just one step above the 5 kW system in this article. A 5 kW system is 12 × 410 W modern Tier 1 panels, fits on roughly 250 sq ft of roof, and is the smallest system that can meaningfully offset a household's electricity bill. It is the most popular starting size for U.S. residential solar.

The Formula

kWh/day = System kW × Peak Sun Hours × Derate factor

For a 5 kW system at PVWatts v8 default derate of 0.83:

kWh/day = 5 × PSH × 0.83

Where PSH is the peak sun hours per day at your location. The U.S. range is roughly 3.2 PSH (Anchorage) to 6.5 PSH (Phoenix).

The 0.83 derate absorbs: 2 % soiling, 3 % shading, 2 % mismatch, 2 % wiring, 0.5 % connectors, 1.5 % LID, 1 % nameplate tolerance, 3 % availability (combined = 14 % DC loss), plus ~96 % inverter efficiency. See How To Calculate Solar Panel Output for the full derate breakdown.

5 kW System Output In 12 U.S. Cities

Using actual NREL PVWatts v8 annual peak sun hours for each location:

Average U.S. household uses 10,500 kWh/year or 877 kWh/month (EIA 2024).

Key takeaways:

• A 5 kW system fully offsets a typical home only in the sunniest Southwest locations
• In the mid-Atlantic and Midwest (Boston, Chicago), it covers about 60–70 % — plan on 7–8 kW to fully offset
• In the Pacific Northwest and Alaska, it covers only 46–57 %
• Annual savings depend more on your state's electricity rate than on sun: a 5 kW system in Los Angeles saves more money ($2,552/year) than the same system in Phoenix ($1,389/year) despite producing less energy, because California rates are 2× higher

Monthly Seasonal Breakdown — Why Annual Averages Can Be Misleading

The annual number averages out a huge seasonal swing. Here is a 5 kW system in Boston (representative of the northern U.S.) and Phoenix (the sunny extreme):

Boston's December (285 kWh) is just 36 % of its June (790 kWh). Phoenix's seasonal variation is much flatter — December is still 64 % of June. This seasonality matters for two reasons:

1. Net-metering credits. Overproduction in summer banks credits against underproduction in winter. If your utility does annual true-up (California), this works well. If they do monthly true-up or net billing, you may lose summer credit value.
2. Battery sizing. If you're off-grid, the battery bank has to survive December, not June. A 5 kW system in Boston that "averages" 18.3 kWh/day actually delivers only 9.2 kWh/day in December.

For the full monthly breakdown at your location, use NREL PVWatts or our peak sun hours calculator.

What A 5 kW System Looks Like In Practice

This is a straightforward one-day install for a two-person crew. The panels fit on a single south-facing roof section of most U.S. suburban homes.

2026 Cost And Payback — The Tax Credit Has Ended

Payback by market:

The tax-credit termination hits hardest in the middle-of-the-road markets (average rates, average sun) — adding ~3.5 years to payback. In high-rate states (HI, CA, MA, NY) the math still works comfortably.

Common Misreadings

1. "A 5 kW system produces 5 kWh per hour." Only at STC conditions (1,000 W/m², 25 °C). In the real world, the system produces ~4 kW at noon on a clear day and tapers toward zero at dawn and dusk. The daily total is what matters, not the instantaneous peak.
2. "5 kW produces the same everywhere." No — Phoenix gets 66 % more energy per year from the same 5 kW system than Seattle does. Location is the single biggest variable.
3. "The 0.75 derate is wrong / the 0.83 derate is wrong." Both are defensible. 0.75 is the PVWatts v1 legacy value (conservative); 0.83 is PVWatts v8 (matches modern equipment). Use 0.83 to compare against installer quotes; use 0.77 as a conservative planning margin.
4. "Annual kWh ÷ 12 = monthly kWh." Only as a rough average. The seasonal variation is ±40 % in northern latitudes. Use the monthly table or PVWatts for accurate month-by-month numbers.
5. "5 kW covers the average home." Almost, but not quite. The average U.S. home uses 10,500 kWh/year; a 5 kW system produces ~7,560 kWh/year at average sun — about 72 %. To fully offset, size up to 6.5–7 kW.

Bottom Line

A 5 kW solar system — 12 modern 410 W panels on roughly 250 sq ft of roof — produces about 20.7 kWh/day and 7,560 kWh/year at U.S. average sun. That covers about 72 % of a typical American home's electricity. In 2026, the installed cost is about $15,500 without the federal tax credit, with payback ranging from 5 years in Hawaii to 15+ years in low-rate Pacific Northwest markets.

Use the calculator below to compute the output for your specific system and location.

Keep Reading

If you found this useful, these guides go deeper into related topics:

• How Much Power A 10 kW Solar System Produces
• How Many Panels In A 1kW–20kW Solar System
• How To Calculate Solar Panel Output
• How Many Solar Panels For 1,000 kWh Per Month
• How Many Solar Panels For 2,000 kWh Per Month
• Standard Solar Panel Sizes And Wattages
• Average Peak Sun Hours By State
• Solar Panel Calculator — Full Energy Estimate
• Rooftop Solar Calculator — How Many Panels Fit On Your Roof