Solar Panels

Best Solar Panel Tilt Angle by Latitude (Year-Round and Seasonal)

Best Solar Panel Tilt Angle by Latitude (Year-Round and Seasonal)

For a fixed system used all year, tilt your panels at an angle roughly equal to your latitude (often slightly less, latitude × 0.9, for best annual output) and face them toward the equator: true south in the northern hemisphere, true north in the southern hemisphere. For winter-heavy off-grid use, tilt about latitude + 15°; for summer use, latitude − 15°.

Solar panel tilt angle calculator

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Why tilt matters

Panels produce most when sunlight hits them at 90°. The sun’s height changes with your latitude and the season, so the best fixed angle is a compromise across the year.

CityLatitudeYear-round tiltWinter-optimisedSummer-optimised
Miami25.8° N23 – 26°40°11°
Phoenix33.4° N30 – 33°48°18°
Los Angeles34.1° N31 – 34°49°19°
Denver39.7° N36 – 40°55°25°
New York40.7° N37 – 41°56°26°
Seattle47.6° N43 – 48°63°33°
London51.5° N46 – 52°67°37°
Toronto43.7° N40 – 44°59°29°
Munich48.1° N44 – 48°63°33°
Sydney33.9° S30 – 34° (facing north)49°19°

How forgiving is tilt?

Very. Being 10 to 15° away from the optimum usually costs only a few percent of annual output. That is why most homeowners simply mount panels flush to their roof pitch:

Roof pitchAngleTypical annual loss vs optimal (mid-latitudes, south-facing)
4/1218°about 3 – 6%
6/1227°about 1 – 3%
8/1234°under 2%
Flat (0°)0°about 10 – 15%, worse in winter

Flat panels also collect dust and stay wet, and lose much more in winter, which matters for off-grid and RV systems.

Direction (azimuth)

  • Due south (northern hemisphere) is best for total output.
  • East or west facing roofs produce about 10 to 20% less annually than south, but spread production across morning or afternoon, which can suit time-of-use rates.
  • Use true south, not magnetic south. Magnetic declination can be more than 10° in parts of the US.

Seasonal adjustment

If you have an adjustable ground mount, changing the angle two to four times a year can add roughly 5% annual output, and much more in winter:

  • Spring and autumn equinox: tilt ≈ latitude
  • Winter: latitude + 15°
  • Summer: latitude − 15°

Trackers

Single-axis trackers that follow the sun from east to west can add roughly 20 to 30% annual output, and dual-axis trackers a bit more, but they add cost, moving parts and maintenance. For small systems, adding panels is usually cheaper.

Tilt for off-grid winter performance

Off-grid systems often run short in December, so tilt steeply (latitude + 15° or more). Steep panels also shed snow. See winter off-grid solar.

Your tilt affects your effective peak sun hours; plug the right figure into the solar calculator. See also peak sun hours.

Worked example: choosing between roof pitch and a tilt kit

A home in Dallas (32.8° N) has a flat roof. The owner can mount panels at 10° (low, quick, less wind load) or at 30° (closer to optimal):

TiltApprox. annual energy vs optimumWinter energy vs optimumNotes
10°about 95%about 85%Less wind load, closer row spacing, more dust buildup
20°about 98%about 93%Good compromise
30°100%100%Best annual yield, needs wider row spacing

Approximate figures. For a grid-tied home under net metering, 15 to 20° often gives the best balance of output, wind loading and how many panels fit. For an off-grid home that struggles in winter, 30 to 45° is better.

Row spacing on flat roofs and ground mounts

Tilted rows cast shadows on the row behind. A common rule is to avoid shading between about 9 am and 3 pm on the shortest day.

Spacing between rows ≈ Panel height above roof × Shadow ratio

At around 30° N latitude, a shadow ratio of about 1.5 to 2 is typical in winter; at 40° N it is closer to 2.5 to 3. For a panel tilted 30° with its top edge 1 m higher than its bottom edge, leave roughly 1.5 to 2 m from the back of one row to the front of the next at 30° N.

Facing the right way

  • In the northern hemisphere, face true south; in the southern hemisphere, true north.
  • Slightly west (10 to 20°) can help if your electricity is more valuable in the late afternoon or evening.
  • Use a compass app with true north enabled, or check on a satellite map.

Common mistakes

  • Setting tilt by eye. Use an angle-finder app on a rail.
  • Using magnetic south where declination is large.
  • Ignoring wind load with steep tilts on flat roofs. Use engineered racking and proper ballast or anchoring.
  • Flat panels in dusty places. At very low tilts, dust and water pool and soiling losses rise.

Seasonal adjustment calendar (northern hemisphere)

PeriodSuggested tilt
Mid-October to late FebruaryLatitude + 15°
Late February to mid-AprilLatitude
Mid-April to late AugustLatitude − 15°
Late August to mid-OctoberLatitude

Southern hemisphere: shift the dates by six months. Adjusting even twice a year (winter and summer settings) captures most of the benefit.

FAQ

What is the best angle for solar panels?

About equal to your latitude for year-round use, facing the equator.

Is 30 degrees a good tilt?

For latitudes between about 25° and 40°, 30° is close to optimal year-round.

Should RV solar panels be tilted?

Tilting RV panels toward the sun when parked for days can add 20 to 40% in winter, but most people mount flat and add portable panels for flexibility.

What tilt is best for solar panels in Texas or Arizona?

Roughly 30 to 33° for year-round output in Dallas (32.8° N) and Phoenix (33.4° N), close to latitude. Use 15 to 20° on flat roofs where wind and space are concerns.

Do adjustable mounts pay off?

On small off-grid systems, manually adjusting twice a year can noticeably boost winter output. On large grid-tied systems, the labour rarely pays.

Does tilt matter for grid-tied systems?

It affects annual output by a few percent; roof pitch is usually fine. Orientation and shade matter more.

Sources and further reading

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