Will this East-ish facing roof work for solar?

Unfortunately, not every roof faces due South. If you have a house with lots of space on an East facing plane, will it work for solar energy production?

To answer that question, we’ll show you some data based on modelling for our own house on Gabriola Island.

As you can see from this Google Earth image, we have solar modules on part of the house but not over the garage. We will be adding modules to this space eventually.

Screen Shot 2019-05-26 at 12.39.12 PM.png

The garage has enough space on the east facing plane (actually it’s even worse at 74 degrees) for 8 modules. They would occupy this space.

Screen Shot 2019-05-26 at 12.42.19 PM.png

The garage roof is 4/12 pitch (approximately 18.5 degrees) and metal. Here are some photos of it from behind and to the side.

IMG_4619.jpg

If the roof were facing due south (180 degrees), this 8 module array (assume we use 295 Watt modules) would generate 2319 kWh/year of energy.

2.1 kW roof due south.png

At an east-ish orientation of 74 degrees, the same array would generate 1924 kWh/year (or approximately 20% less energy per year).

This difference can be almost offset by adding one extra module! Better yet, we could use 8 330 Watt modules and make even more energy (2418 kWh/year).

Michael Mehta