Solar Production by Hour Calculator

See your solar system's 24-hour production curve for any city, month, and panel orientation — compared to your home's typical load profile.

kW
Total daily kWh54.52 kWh
Peak output8,597 W
Peak hour1pm
Daylight hours15.3 hrs
Hourly Production vs Typical Home Load
12am4am8am12pm4pm8pmWattsSolar productionTypical home load
Key insight: In June, your system produces most energy around noon when the typical home uses only ~500W — while evening demand peaks at 1,800W after production has stopped. West-facing panels extend production into the evening to better match your home's load profile. Only 41% of typical home energy use happens during peak solar hours.

How to Use This Calculator

Select location and month

Choose your nearest city from 15 locations and select the month you want to analyze. The calculator adjusts day length, sun angle, and peak sun hours for both location and season — a June day in Phoenix looks very different from a December day in Seattle.

Enter system size and orientation

Enter your system size in kW, select panel orientation (south maximizes total production; east and west shift production to morning and evening respectively), and choose panel tilt. The tilt effect is most significant for south-facing arrays — the optimal tilt for most US homes is approximately equal to your latitude.

Read the hourly chart

The 24-hour bar chart shows solar production (teal bars) vs. typical home load (amber area) by hour. Hours where teal exceeds amber represent solar surplus that goes to the grid or battery. Hours after sunset show the evening load that solar cannot cover — this is where net metering credits or battery storage provide value.

Use orientation to understand self-consumption

East-facing panels produce most power from 6am–noon, aligning with morning routines. West-facing panels produce most power from noon–7pm, aligning with evening peaks (cooking, TV, AC). This is why some installers recommend splitting panels between east and west to flatten the production curve and improve self-consumption.

Solar Production by Orientation: Key Patterns

Orientation Peak Hours vs South Output Best For
South 10am–2pm 100% (baseline) Maximum annual production, most US homes
East 7am–noon 85–90% Morning-heavy households, low TOU morning rates
West Noon–6pm 85–90% Evening peak matching, high TOU afternoon rates
East+West split 7am–6pm 90–95% Flat production curve, high self-consumption
Flat (0°–10°) 9am–3pm 88–93% Flat roofs, minimal wind load concerns

The Solar-Load Mismatch Problem

Solar produces most power between 10am and 2pm — exactly when most homes are empty and energy use is lowest. Evening consumption peaks between 5pm and 8pm — after the sun has set. This mismatch is the fundamental reason solar + battery combinations are becoming increasingly popular.

Typical US home daily load profile: 6–9am: Morning routine (1,200W peak) 9am–5pm: Low daytime use (~500W) 5–9pm: Evening peak (1,800W — cooking, HVAC, TV, charging) Solar production (south-facing, 8 kW, summer, Phoenix): 6–9am: Ramping up (0–3,000W) 9am–1pm: Full power (5,000–7,000W) 1–5pm: Declining (7,000–1,000W) 5pm+: Zero production Surplus solar (noon): 5,000W production vs 500W load = 4,500W exported Evening deficit: 0W production vs 1,800W load = all imported

Under full retail NEM, this mismatch doesn't hurt you — exported kWh credit at the same rate you pay to import. Under NEM 3.0 or avoided-cost NEM, a battery capturing peak noon production and releasing it at 6pm can save $800–$2,000/year by replacing expensive imported evening electricity.

FAQ

For annual production, orientation matters more. A west-facing array loses about 10–15% annual production vs. south, while a tilt that's 15 degrees off optimal loses only 3–5%. However, for self-consumption optimization, orientation shift (east vs. west) matters more than production total — west-facing panels' 5pm production during peak load can be more financially valuable than south-facing noon production under some utility tariffs.
This calculator uses a simplified theoretical model based on city PSH data and standard bell-curve solar production patterns. Your monitoring app shows actual measured production affected by specific shading, cloud patterns, soiling, temperature, and inverter behavior at your exact address on specific days. Expect differences of 10–25% in daily production on any given day. The calculator's value is in understanding the shape and timing of production — not predicting a specific day's output. Use NREL PVWatts for your exact address for more precise hourly modeling.
Yes — if your utility has avoided-cost NEM or TOU rates, running large appliances during 10am–2pm can save $200–$500/year. Dishwasher, laundry, EV charging, pool pump — set these to smart schedules or timers to run at peak solar production hours. With full retail NEM, this optimization has less financial impact (the credit value is the same whether you use it now or export it). With NEM 3.0 or poor export rates, load-shifting is one of the most cost-effective strategies alongside battery storage.
Clouds don't eliminate solar production — they reduce it. Light overcast typically cuts production 40–70%; heavy overcast 80–90%. Interestingly, diffuse (overcast) light is more even throughout the day — the pronounced noon peak flattens. Some locations with frequent morning fog but sunny afternoons (coastal California) actually benefit from west-facing panels. NREL's PSH data for each city already incorporates typical cloud cover patterns — it's an annual average, not a clear-sky calculation.

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