West-Facing Solar Panels Take Heat off Grid in Summer

Flying in the face of convention, new research suggests pointing solar panels west may be more effective—at least during summer in Texas.

The report acknowledges that south-facing solar will produce more total energy over the course of a year, but during Texas’s long summer days, results show west-facing systems generated 4% more electricity per day than comparable south-facing systems.

In addition, west-facing systems better met peak demand by harnessing the sun’s afternoon rays when cooling loads were high; west-facing systems generated 49% more electricity during peak demand hours than south-facing systems. This allowed more energy to be utilized onsite instead of sold back to the grid. Homes with west-facing systems utilized 75% (18.78 kWh) of their PV-generated electricity, while 58% (13.43 kWh) was utilized in homes with south-facing systems.

The study did not look at solar panels installed to track the sun across the sky, which are less common on homes that have roof space but small yards. Also, the decreasing cost of panels means that simply adding more panels is typically more cost-effective than roof-mounted systems, due to the cost of tracking equipment. In fact, 13 of the 50 homes studied had both south- and west-facing panels.

The grid-stabilizing benefits may give utilities more rationale to offer rebates to customers with west-facing systems, but research to analyze whether these benefits outweigh increased pressure on the grid during other seasons is still in development.

For more information:

Pecan Street Research Institute

pecanstreet.org