Optimum orientation of solar panels

To get the most from solar panels you need to point them in the direction that captures the most sun. But there are a number of variables in figuring out the best direction. This page is designed to help you find the best placement for your solar panels in your situation.

This advice applies to any type of panel that gets energy from the sun; photovoltaic, solar hot water, etc. We assume that the panel is fixed, or has a tilt that can be adjusted seasonally. (Panels that track the movement of the sun throughout the day can receive 10% (in winter) to 40% (in summer) more energy than fixed panels. This page doesn’t discuss tracking panels.)

Solar panels should always face true south if you are in the northern hemisphere, or true north if you are in the southern hemisphere. True north is not the same as magnetic north. If you are using a compass to orient your panels, you need to correct for the difference, which varies from place to place. Search the web for “magnetic declination” to find the correction for your location.

The next question is, at what angle from horizontal should the panels be tilted? Books and articles on solar energy often give the advice that the tilt should be equal to your latitude, plus 15 degrees in winter, or minus 15 degrees in summer. It turns out that you can do better than this – about 4% better.

Optimum Tilt of Solar Panels

Equation: If your latitude is between 25° and 50°, use the latitude, times 0.76, plus 3.1 degrees.

Solar panel pitch for Budapest (47.4547N, 19.0498E)

Winter: (47.4547 * 0.89) + 24 = 66.2347ᵒ
Summer: (47.4547 * 0.92) – 24.3 = 19.3583ᵒ
Spring/Autumn: (47.4547 * 0.98) – 2.3 = 44.2056ᵒ
Full year (no adjustment): (47.4547 * 0.76) + 3.1 = 39.1656ᵒ

Solar panel pitch for Mezőszentgyörgy (46.9969N 18.2752E)

Winter: (46.9969 * 0.89) + 24 = 65.8272ᵒ
Summer: (46.9969 * 0.92) – 24.3 = 18.9371ᵒ
Spring/Autumn: (46.9969 * 0.98) – 2.3 = 43.757ᵒ
Full year (no adjustment): (46.9969 * 0.76) + 3.1 = 38.8176ᵒ

Tools to assist in sun calculations

Solar panel pitch for Daruszentmiklós (46.8363N, 18.8594E)

Winter: (46.8363 * 0.89) + 24 = 65.6843ᵒ
Summer: (46.8363 * 0.92) – 24.3 = 18.7894ᵒ
Spring/Autumn: (46.8363 * 0.98) – 2.3 = 43.5996ᵒ
Full year (no adjustment): (46.8363 * 0.76) + 3.1 = 38.6956ᵒ

Written by norton