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Solar Performance

Homes and businesses can readily benefit from solar power systems, especially where full solar exposure is available.

Even during cloudy conditions a solar array will produce power on a daily basis. It's not even necessary to service or clean a solar array, and the included monitoring system allows detailed tracking of performance and identifying if there is an issue.

Solar performance is directly linked to the intensity of unobstructed, direct sunlight on the face of a solar panel. Forested locations and north-facing hillsides, have a much lower solar resource compared to locations with full open southern exposure.

There are a number of factors affecting solar performance and efficiency, the most significant being the exposure and orientation of the solar array:

Exposure / Shading​​ Trees, power poles, chimneys, vents, antenna, or other structural elements of the building can shade out an otherwise usable area for solar panels and are best avoided.

Terrain can also limit the hours of solar exposure, especially during the winter. But since most solar energy is available when the sun is high (mid-day), some inevitable shading during the first and last hour of the day may be negligible.

Snow cover is able to completely black out a solar panel, but a light snow can quickly melt away on a sunny day. Heavier snow loads may take some time, but once some of the solar panel is exposed, sun heating the panel can clear the panel with a little more time. Snow cover causes about 5% to 10% power loss per year. Given that snow cover happens most when there is the least sunlight, the losses aren't very significant.

Orientation and Pitch A solar array is best oriented south, but anywhere between south-east and south-west is great. One way or the other simply favors morning or evening performance. Roofs facing directly east or west may be suitable in some cases.

Pitch (or tilt) is important, as it relates to seasonal performance. High-pitched roofs are desirable for improving wintertime performance and shedding snow. Lower-pitched roofs are best for summer performance. Flat roofs aren't very practical at a northern latitude, unless a tilted platform can be installed. In some cases it may be favorable to tilt a solar array up on a low-pitch roof, but most often it is preferable for the array to match the roof pitch.

If for any reason a roof mount is unfavorable, a ground-based installation may be considered. Mounting on the ground is not always ideal, but the orientation and pitch of the array can be optimized for maximum performance.


Black Hills Solar provides professionally installed solar power systems, energy storage systems, and electrical services.


Rapid City, Black Hills, South Dakota

Please contact us to make an appointment.

Serving Counties: Pennington, Meade, Custer, Fall River, Lawrence, Butte, Weston, Crook

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