In short: In the Northern Hemisphere, the best roof direction for solar panels is south; in the Southern Hemisphere, it’s north. The best tilt is roughly equal to your latitude, often a few degrees less. But you don’t need a perfect roof: east- and west-facing roofs still produce well, and a tilt within about 15 degrees of the ideal costs only a few percent of annual output.
Many homeowners rule out solar because their roof doesn’t face the «right» way. In practice, orientation matters less than shading, and in some cases a west- or east-facing roof can even make financial sense. This guide explains how direction and angle affect production, what to do with less-than-ideal roofs, and how to check your own home.
Why direction and tilt matter
Solar panels produce the most electricity when sunlight hits them straight on. Because the sun sits in the southern half of the sky in the Northern Hemisphere (and the northern half in the Southern Hemisphere), panels facing the sun’s path collect more energy over a year. The tilt determines how well panels match the sun’s height in the sky across the seasons.
Installers describe direction as azimuth: the compass direction your panels face. Tilt is the angle of the panels from horizontal.
Best roof direction for solar panels
Northern Hemisphere (US, UK, Canada, Europe)
South-facing roofs generally produce the most electricity over a year.
Southern Hemisphere (Australia, New Zealand, South Africa, much of South America)
North-facing roofs are best.
Near the equator
Direction matters less, and panels are often mounted at a low tilt.
How much do you lose with other directions?
These are rough figures for the Northern Hemisphere at typical mid-latitudes, compared with a well-tilted south-facing roof. The exact loss depends on your location, tilt, and shading:
| Roof direction (Northern Hemisphere) | Approximate output vs ideal | Verdict |
|---|---|---|
| South | 100% | Best |
| Southeast or southwest | about 93–98% | Excellent |
| East or west | about 80–90% | Good; often worth it |
| Northeast or northwest | about 65–80% | Depends on price and sun |
| North | about 55–70% (often less on steep roofs) | Usually the last choice |
In sunnier regions, the gap between directions is often smaller in absolute terms, because even a less-than-ideal roof gets plenty of sun. Ask your installer for a site-specific production estimate for each roof face rather than relying on general rules.
Are east- and west-facing panels worth it?
Often, yes. A few reasons:
- Lower loss than you’d think: east- or west-facing roofs typically lose roughly 10–20% of annual output compared with south-facing ones.
- Better timing: south-facing panels peak around midday, while east-facing panels produce more in the morning and west-facing panels produce more in the afternoon and early evening. If you’re home in the evening, or your export rate is low, west-facing production can be more valuable to you.
- Split systems: installing panels on both east and west roof faces gives a flatter production curve throughout the day. Total output may be slightly lower, but more of it matches when you actually use power.
- More panels fit: if the south-facing roof is small or obstructed, using additional faces can allow a larger system.
See how export rules change the value of solar timing in Net Metering vs Export Tariffs.
Best tilt (angle) for solar panels
A common rule of thumb is that the best fixed tilt for year-round production is about your latitude, or a few degrees less. The rough ranges below are for well-oriented panels:
| Example location | Latitude | Typical best tilt (approx.) |
|---|---|---|
| Miami, FL | 26°N | 20–26° |
| Phoenix, AZ | 33°N | 28–33° |
| Denver, CO | 40°N | 33–38° |
| Seattle, WA | 47°N | 35–42° |
| London, UK | 51°N | 30–40° |
| Sydney, Australia | 34°S | 28–33° (north-facing) |
The good news: production is quite forgiving. Being 10–15 degrees off the ideal tilt typically costs only a few percent of annual output. Most standard pitched roofs (roughly 20–40 degrees) are already close to ideal, so most installers simply mount the panels flush with the roof.
Summer vs winter tilt
- Steeper tilt favors winter production, when the sun is low, and helps shed snow.
- Flatter tilt favors summer production, when the sun is high.
If most of your consumption or value comes in winter (for example, electric heating), a steeper tilt may suit you better.
What about flat roofs?
Flat roofs give you freedom to choose direction and tilt, using mounting frames. Common approaches:
- South-facing frames (Northern Hemisphere) at 10–30 degrees, with wide row spacing to avoid self-shading. This gives higher output per panel but fewer panels per roof.
- East-west «low tilt» layouts (around 5–15 degrees) that pack more panels on the roof, resulting in higher total capacity and a flatter production profile.
Also consider wind load and roof structure: your installer should check these. See Solar Panels on Flat, Metal, Tile and Slate Roofs for roof-type details.
Shading matters more than direction
A perfectly oriented roof with heavy shading can perform worse than an east-facing roof with none. Check for:
- Trees (including how they’ll grow over the next 10–20 years).
- Chimneys, dormers, and neighboring buildings that cast shadows, especially in winter when the sun is low.
- Time of day: shade in the early morning or late afternoon matters less than shade around midday.
Panel-level electronics, such as microinverters or optimizers, can reduce the impact of partial shading. Read more about shading and production losses.
How to check your own roof
- Find south (or north in the Southern Hemisphere) with a compass app or an online map and see which roof faces are closest to it.
- Check your roof pitch using a level and tape measure, or a smartphone inclinometer app. Note that US pitch is often written as a ratio (for example, 6/12 is about 27 degrees).
- Look for shade at different times of day and in winter if you can.
- Use a free tool: NREL’s PVWatts (US) lets you enter direction and tilt and estimates production. Many installers also use satellite-based design tools.
- Ask for a production estimate for each roof face in your quotes.
Common mistakes
- Dismissing east- and west-facing roofs without checking the numbers.
- Over-focusing on perfect angle and ignoring cost: adding tilt frames to a pitched roof usually isn’t worth the extra money.
- Ignoring shade from trees or nearby buildings that will grow or be built.
- Using the wrong hemisphere’s rule. Check which direction the sun is in your location.
- Using the same estimate for every roof face. Each orientation should have its own production number.
Next steps
- Identify which roof faces you have and how much unshaded space each offers.
- Ask installers for production estimates for each face.
- Work out your size needs with How Many Solar Panels Do I Need?
- Compare quotes and spot red flags before you decide.
Frequently asked questions
What is the best direction for solar panels?
In the Northern Hemisphere, south-facing. In the Southern Hemisphere, north-facing. Roofs facing a few degrees off ideal lose very little.
Can you put solar panels on a north-facing roof?
Yes, in the Northern Hemisphere, but output is usually much lower than on other faces, so it’s rarely the best choice unless it’s your only option and the economics still work. In the Southern Hemisphere, a north-facing roof is the ideal one.
Do east-west solar panels work?
Yes. East- and west-facing panels typically produce roughly 10–20% less annually than a south-facing roof, but they spread production across the day, which can suit household use and some tariffs.
What is the best angle for solar panels?
Roughly your latitude, or slightly less, for year-round production. Most pitched roofs are close enough that mounting panels flush is fine.
Does roof pitch matter for solar?
A little. Most typical pitches (about 20–40 degrees) perform well. Very flat or very steep roofs may reduce output slightly or affect installation cost.
Is a flat roof good for solar panels?
Yes. Mounting frames let you choose direction and tilt, so a flat roof can perform as well as a pitched one, though the mounting hardware adds cost and design considerations such as wind loading.