Solar Panel Orientation and Tilt

Two angles determine how much of the available sunlight your array captures: which way it faces (azimuth) and how steeply it's angled (tilt). Between them they move annual production more than panel selection does.

Output by orientation, northern hemisphere

Approximate share of the optimum, for a fixed array.

Tilt matters less than azimuth: anything between about 15° and 40° lands within a few percent of ideal. Latitude-equal tilt maximises the annual total, a shallower tilt favours summer, a steeper one favours winter and sheds snow better.

Under time-of-use rates, west-facing can beat south despite lower total output, because it shifts production into the expensive late-afternoon window.

Which direction should solar panels face?

In the northern hemisphere, the sun tracks across the southern sky. A south-facing array therefore captures the most total energy over a year.

Moving away from south costs production — modestly for southeast and southwest, more for due east and west, substantially for north.

But total production isn't always what you're optimizing.

Are west-facing solar panels better?

This is the most useful thing in this guide.

South-facing peaks around solar noon and produces the most total kWh.

West-facing shifts the production curve later — less total energy, but more of it arriving in the late afternoon and early evening.

Under a time-of-use rate where afternoon and evening electricity is expensive, that shift can be worth more than the extra kilowatt-hours a south-facing array would produce. You're generating when energy is most valuable rather than when there's most of it.

The same logic applies to self-consumption: if your household load peaks after work — cooking, air conditioning, EV charging — west-facing production is more likely to be used directly rather than exported at a lower credit rate.

So the right question isn't "which direction produces most?" but "which direction produces the most value under my rate structure?" See time-of-use rates and solar and net metering explained.

East-facing does the reverse — morning production, useful for households with high morning load, less commonly the better economic choice.

What tilt should solar panels have?

Tilt determines how directly panels face the sun as it moves through the sky and the seasons.

Roughly latitude-equivalent tilt approximately maximizes annual production.

Lower (flatter) tilt favours summer, when the sun is high. It also collects more soiling, since rain runs off less effectively, and sheds snow poorly.

Higher (steeper) tilt favours winter, when the sun is low. It sheds snow better and self-cleans better in rain.

On a pitched roof, tilt is whatever the roof is. The good news is that the difference between a typical roof pitch and the theoretical ideal is usually modest — well within the range where it isn't worth engineering around.

On a flat roof or ground mount, you choose. See ground mount vs roof mount solar.

Should you adjust solar panel tilt seasonally?

Adjustable racking that lets you change tilt seasonally exists and does raise annual production somewhat.

For most residential installations it isn't worth it:

• The gain is modest
• It requires physically adjusting the array twice a year, on a roof
• Adjustable racking costs more and adds mechanical complexity
• Nobody keeps doing it after the first couple of years

For ground mounts where adjustment is easy and safe, it's more defensible. For roof arrays, size the system slightly larger instead.

Tracking systems

Motorized mounts that follow the sun. They increase production meaningfully — and for residential use they're rarely justified:

• Substantially higher cost
• Moving parts that require maintenance, on a system whose main appeal is having none
• Mostly used with ground mounts
• The same money spent on additional fixed panels usually produces more energy per dollar

The general rule in residential solar: more panels beats cleverer mounting.

What if my roof does not face south?

Most homeowners don't choose orientation — the roof decides.

Practical guidance:

Multiple roof planes are normal. Splitting an array across a south and a west plane is common and often good, since it broadens the production curve. It does require inverter configuration that handles different orientations — microinverters or optimizers handle this naturally, while a single string inverter needs separate inputs. See string inverters vs microinverters.

East-west split arrays on a ridge produce a flatter, broader curve than a single south array — less peak, longer duration. Often good for self-consumption.

Don't force a bad plane. A north-facing plane in the northern hemisphere rarely earns its cost, unless the roof is nearly flat.

Don't ignore a decent plane because it isn't perfect. A southwest plane at a slightly wrong pitch is usually fine.

Shading beats orientation. A perfectly oriented plane with afternoon shade underperforms a southwest plane in full sun. Assess shading first. See how shading affects solar panels.

What this means for sizing

If your available orientation is less than ideal, the answer is usually more panels, not a different technology.

Orientation losses are proportional, so a fixed percentage more capacity restores the target production — provided you have the roof space. If you don't, that's where higher-efficiency panels earn their premium. See solar panel efficiency explained.

Run both scenarios with the solar output calculator and the solar panels needed calculator.

Evaluating a proposal

Check that the estimate:

• States the azimuth and tilt of each roof plane used
• Models each plane separately rather than averaging
• Accounts for shading on each plane
• Provides monthly production, so you can see the seasonal shape
• Considers your rate structure if you're on time-of-use

A proposal that treats a multi-plane roof as one orientation is oversimplifying, and the estimate will be off.

The bottom line

South-facing maximizes total annual production, but west-facing shifts output into expensive afternoon hours — and under time-of-use rates or with evening-heavy consumption, that shift can be worth more than the kilowatt-hours you give up. Tilt is usually fixed by your roof and the penalty for being off-ideal is modest. Skip seasonal adjustment and tracking; if orientation costs you production, buy more panels instead.

Estimate production with the solar output calculator, size with the solar panels needed calculator, or read peak sun hours explained.