Which Way Should Solar Panels Point?

Solar panels are becoming more affordable and therefore more popular for homeowners. Photo: morgueFile/Seemann

For years, experts have believed that south-facing solar panels are most effective in gathering sun in the northern hemisphere. But a new study based on homes in Austin, Texas, has raised questions about which way our solar panels need to be facing.

The Pecan Street Research Institute released results of a study that indicated homeowners could find significant benefits by pointing their solar panels to the west. The study concluded that the west-facing panels were better at reducing peak loads in areas such as Austin, where air-conditioning use is a strong driving factor in energy use during peak times, typically 3 p.m. to 7 p.m.

The study showed south-facing panels provided a 54 percent peak-reduction in usage, while the panels facing west produced a more impressive 65 percent reduction.

But that doesn’t mean it’s time to tear down those south-oriented solar panels and put them on west-facing roofs just yet. While the study results immediately led to reports that homeowners could get greater results by pointing their solar panels to the west, there was more to the story than many reported.

While the study found that west-facing configurations did have their benefits, they produced less total energy over the course of the year than their south-facing counterparts. The value, it appears, is that they are able to help reduce the electricity load during peak times, which of course puts less stress on electricity distribution systems. That means the power they produce may be more valuable, particularly in hot climates where air-conditioning use can cause problems such as rolling blackouts during peak hours.

The new study raises the question of whether using west-facing solar panels may help offset some of the power usage during peak hours and provide some relief for the energy grid. More research is planned that will include broadening the region being studied and examining how the pitch of the roof affects solar collection.