Which Way Should Solar Panels Face?
In Canada, panels yield the most facing true south at a tilt roughly equal to the latitude, but east and west faces still produce well, typically 10 to 20 percent less over a year. Shading usually matters more than a modest departure from south.
What is the best direction for solar panels in Canada?
In the northern hemisphere the sun spends the day in the southern half of the sky, so south-facing panels capture the most energy across a year. That means true south, which differs from magnetic south by a few degrees that vary by location, so installers use a compass with the local declination or a site model.
A roof within about 30 degrees of south loses little. An east or west roof commonly gives roughly 80 to 90 percent of the best-orientation output, which is often still worth installing, particularly if rates are high or the roof offers no better face. A modelled estimate with your exact azimuth is far better than guessing; see peak sun hours in Canada for the underlying numbers.
What tilt angle works best at Canadian latitudes?
A common starting point for annual energy is a tilt near the latitude. Southern Alberta sits around 50 degrees north, so something close to 40 to 50 degrees is a sensible target if the roof allows. Many roofs are 20 to 35 degrees, and the penalty for being off the ideal is modest, a few percent.
Steeper tilts favour winter, when the sun is low, and they shed snow better; see snow removal on solar panels. Shallower tilts favour summer. A ground mount can be set to suit your goal, while a roof mount uses the roof pitch unless frames raise it, at an extra cost.
Two practical notes. First, roof framing may decide the matter: panels must attach to rafters, and a roof with awkward spacing can limit how the rails are laid out. Second, some installers offer tilt-up frames on a flat roof, which allow an ideal angle but add wind loading and ballast or anchors, and so cost more. Ask for production estimates for each option, not just for the preferred one, so you can see exactly what a better angle buys and judge whether the extra spend is justified.
Are east-west systems a good idea?
They can be. Panels split across an east and a west face produce earlier and later in the day, giving a flatter curve than a single south array. That can match morning and evening household use better and reduce the midday peak that the inverter must handle. Total annual output is lower per panel, so you need more modules for the same energy.
With export credits that pay less than retail, shaping production to your own use can beat raw yield. Monitoring tools, explained in what to track on a solar system, show the daily shape clearly after installation.
How much does shading matter?
A great deal. A shadow across part of a string can pull down output of every panel on it, depending on the electronics. A few trees, a chimney or a neighbouring gable may cost more than a 30-degree turn away from south. Microinverters or optimizers limit the damage by treating panels independently; the trade-offs are in solar inverter types.
A site visit should map shadows across the year, since the low winter sun throws long shadows that summer surveys miss. Trimming a tree may be cheaper than changing panel layout.
Does the same logic apply to solar heating?
For heat the winter sun is what counts, so collectors are tilted steeper than for annual electricity. At Okotoks the collector rows sat on garage roofs that faced the sun, a layout that made sense for a neighbourhood plan with lanes and garages; see solar collection. The same thinking is developed in solar collector tilt for winter heating.
Quick answers
Can solar panels face west?
Yes. West-facing panels typically produce somewhat less per year than south-facing ones, but they generate more in the late afternoon and evening, which can match household use.
What is the ideal tilt for solar panels in Alberta?
Roughly 35 to 50 degrees works well for annual output, with steeper angles favouring winter. Most roof pitches are acceptable, and the loss from a modest mismatch is small.
Do north-facing roofs work for solar?
Rarely well. Output is much lower, and most installers advise another roof face or a ground mount instead.