Solar Energy in Durham, North Carolina

Average Solar Resource Pop. 278,993

Durham, North Carolina receives 4.43 kWh/m²/day of solar irradiance and 5.1 peak sun hours daily, representing average solar resources . A typical 5 kW residential solar system in Durham produces approximately 7,475 kWh annually, potentially saving homeowners $882 per year on electricity bills. After the 30% federal Investment Tax Credit, a 5 kW system has an estimated payback period of 11.9 years, leaving roughly 13 years of profitable operation within a standard 25-year warranty. For maximum annual output in Durham, panels should be tilted at approximately 36° and oriented true south (180° azimuth).

Solar Resource Summary

4.43
kWh/m²/day
5.1
hours/day
4.52
kWh/m²/day
GHI vs. US national average (4.5 kWh/m²/day) Average
0 7.5 kWh/m²/day

Monthly Solar Data

Month JanFebMarAprMayJunJulAugSepOctNovDec Annual
GHI (kWh/m²/d) 2.58 3.41 4.45 5.43 6.12 6.24 6.0 5.52 4.55 3.65 2.8 2.32 4.43
DNI (kWh/m²/d) 4.23 4.7 5.01 5.05 5.03 4.85 4.61 4.47 4.16 4.27 4.01 3.83 4.52
Source: NREL. Monthly averages in kWh/m²/day and °C.

Solar Production Estimates for Durham

5 kW Residential
Typical home system
Residential
7,475 kWh/yr
623 kWh/month avg
≈ $882/year savings
10 kW Residential
Large home system
Residential
14,950 kWh/yr
1,246 kWh/month avg
≈ $1,764/year savings
50 kW Commercial
Small commercial
Commercial
74,752 kWh/yr
6,229 kWh/month avg
100 kW Commercial
Medium commercial
Commercial
149,504 kWh/yr
12,459 kWh/month avg

Production estimates based on NREL solar resource data, 36° tilt, south-facing orientation, and 80% performance ratio.

Local Solar Conditions in Durham

Durham shows significant seasonal variation in solar output, with peak summer months receiving 6.2 kWh/m²/day compared to 2.3 kWh/m²/day in winter — a 2.7x difference. Battery storage or net metering is particularly valuable here.

Best Tilt Angle
36° (latitude-optimized)
Best Azimuth
180° (true south)
Coordinates
35.994°N, -78.8986°

Financial Overview — Solar in Durham

Solar is a sound investment in Durham. A 11.9-year payback period is in line with the national average. With electricity rates likely to increase over time, actual payback may be shorter. Estimated annual savings from a 5 kW system: $882/year.

Avg. Electricity Rate
$0.118/kWh (NC avg)
Est. Annual Savings (5 kW)
$882/year
Est. Payback Period
11.9 years (after 30% ITC)
Federal ITC
30% of system cost
Net Metering
Available
Financial estimates assume a 5 kW system at $3,000/W installed ($15,000 pre-ITC, $10,500 after 30% credit). Actual costs vary by installer and equipment. Consult a local solar installer for firm quotes.

Solar FAQ — Durham, North Carolina

In Durham, North Carolina, a 5 kW residential solar system produces approximately 7,475 kWh of electricity per year. A 10 kW system produces about 14,950 kWh annually. These estimates use 4.4 kWh/m²/day average solar irradiance and an 80% system performance ratio, accounting for real-world losses from wiring, inverter efficiency, and temperature. Actual output will vary based on your specific roof orientation, shading, and equipment.

Durham receives an average Global Horizontal Irradiance (GHI) of 4.43 kWh/m²/day. This is 0.07 kWh/m²/day below the US national average of 4.5 kWh/m²/day, placing Durham near the national average. GHI measures total solar energy incident on a horizontal surface and is the primary indicator of a location's solar resource quality.

Durham, North Carolina receives an average of 5.1 peak sun hours per day. Peak sun hours represent the equivalent number of hours when solar irradiance equals 1,000 W/m² — the standard condition used to rate solar panel output. This means a 1 kW solar panel array in Durham produces 5.1 kWh on a typical day. Seasonal variation is significant: summer months see peak sun hours 40–60% higher than winter months in most US locations.

Durham is a average location for solar panels, with 4.43 kWh/m²/day solar irradiance — near the national average. With an estimated payback period of 11.9 years, solar installations in Durham can be financially attractive, especially given North Carolina's electricity rates.

The optimal tilt angle for solar panels in Durham is approximately 36°, which corresponds to the city's latitude. This angle maximizes annual energy production by ensuring panels receive the most direct sunlight averaged over the year. For maximum winter output, tilt panels at latitude + 15° (51°). For maximum summer output, use latitude − 15° (21°). Fixed south-facing panels at the latitude angle are the standard recommendation for residential systems in Durham.

A 5 kW solar system in Durham can save an estimated $882 per year on electricity bills, based on Durham's average electricity rate of $0.118/kWh. Over a 25-year system lifetime, that represents $22,050 in total savings before accounting for electricity rate increases. After the 30% federal Investment Tax Credit, the net system cost of approximately $10,500 for a 5 kW system yields a payback period of 11.9 years.

For a typical home in Durham using 1,000 kWh/month, a 5 kW solar system producing 623 kWh/month would offset approximately 62% of a typical household's electricity use. Most residential installations in similar climates range from 5 to 12 kW depending on energy consumption, roof size, and budget. Use SolarScope's Site Studio to get a personalized system size recommendation based on your specific address and energy bills.

Based on local solar irradiance and electricity rates, a 5 kW residential solar system in Durham has an estimated payback period of 11.9 years. This calculation assumes a net system cost of $10,500 (after the 30% federal ITC) and annual savings of $882. Modern solar panels carry 25-year performance warranties, so systems in Durham would operate profitably for roughly 13 years after payback. Electricity rate increases over time typically reduce the effective payback period.

Get a Detailed Solar Analysis for Durham

This page shows area-level averages. For your specific address — accounting for roof orientation, shading trees, and your utility rate — use SolarScope's AI-powered Site Studio.

Open Site Studio Community Data for North Carolina

Quick Stats

Annual GHI
4.43 kWh/m²/day
Peak Sun Hours
5.1 h/day
5kW Production
7,475 kWh/yr
Payback (5kW)
11.9 years
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