How Orientation, Tilt and Shading Affect Solar Power Output

To design a home PV system with optimal solar power output, professional contractors need to consider a number of factors. Orientation, tilt and shading are of special importance, as they all have a major impact on the amount of sunlight that reaches the photovoltaic panels.

Orientation, Tilt and Shading Affect Solar Power Output

Orientation and Solar Power Output

For home PV systems installed in the Intermountain West, due south is the ideal orientation for harnessing maximum solar power.

But what if your roof doesn’t face south? Can rooftop solar panels produce enough energy to power your home?

That depends upon your rooftop’s orientation. According to the Department of Energy, photovoltaic panels can face up to 45 degrees east or west of due south without a noticeable drop in energy production.

What if your rooftop faces too far east or west? Or if the only usable roof space points north? In either of those cases, professional contractors often recommend installing a ground-mounted solar power array. Or the photovoltaic panels could be installed on another structure, such as a garden shed, awning or parking canopy.

Tilt and Solar Power Output

Most photovoltaic panels are mounted on rooftops, flat against the surface. But not every roof is angled to best capture the sun’s energy.

The DOE says the optimal tilt angle for a home PV system is equal to your latitude. So for example, in Salt Lake City, roughly 40 degrees would be the ideal tilt in terms of solar energy output.

Many Intermountain West homes have rooftops pitched at angles less than the local latitude. Since tilt can significantly affect solar power production, professional contractors factor in the roof angle when sizing a home PV system. For flat or low-sloped roofing, special brackets may be used to achieve a more favorable tilt angle.

Shading and Solar Energy Output

Shading is of major importance when designing a home solar panel system. You could have a south-facing roof at the optimal tilt angle, but if the photovoltaic panels are shaded, your solar energy production will suffer greatly.

Professional contractors perform an analysis to determine how much the solar panels will be affected by shade from nearby buildings and trees. The analysis considers the path the sun takes during the course of the day and during different seasons.

If shading is a significant problem, an effective home PV system design may include micro-inverters. With micro-inverters, each module operates independently. So if one of the photovoltaic panels is shaded, the others will continue to produce electricity.

Installing a ground-mounted array can also solve shading problems. In some cases, going this route results in greater solar energy output.

The professional contractors at Intermountain Wind & Solar, the leading photovoltaic provider for Utah, Colorado, Idaho, Nevada and Wyoming, have the experience to design an effective home PV system that offers maximum solar power output. For a free consultation, contact us today.