What is the optimum angle for solar panels at our latitude?
The usual rule of thumb is, relative to your latitude (e.g. Antigonish and Halifax are at 45, Sydney is at 46) 15° more upright in the winter, 15° flatter in the summer. But of course hardly anyone adjusts their racks by the seasons. Most people compromise on 45 or a few degrees flatter, e.g. 40, but, the panels will shed snow better if they’re steeper in the winter. Here’s a long but accurate discussion of it: http://www.solarpaneltilt.com/