There are many things to consider when making the transition to solar, not the least of which being where to put your solar system. In general, roof mount solar arrays are less expensive and easier to install than ground mount solar systems, which have a slight efficiency advantage. Below are a few considerations when deciding which to pursue.
Solar panels measure about 40 inches by 65 inches, and the rows of a roof-mounted system should be placed at least 4 feet apart. If you know how many solar panels you need to meet your energy goal and how you’d like to configure your array, you can easily calculate the required space. Below is an example for a 30 panel system.
Configuration: 3 rows of 10 panels oriented in portrait
Width: 40 in. x 10 panels = 400 in. = 33 ft.
Height: 65 in. x 3 rows = 195 in. = 16 ft. (plus 8 feet spacing for roof mount)
From these calculations I know that I’ll need at least about 35 ft. by 20 ft. of space for the system, or about 40 feet by 25 feet on a roof in order to leave enough room for installation. If either the yard or roof is lacking in the necessary amount of space, it is a deal breaker for that location.
2. Southern Exposure
In the Northern Hemisphere it is necessary for panels to face South in order to be cost-effective. If your roof faces East/West and does not have the necessary space requirements facing South, then a ground mount is required in order to best capture the sun. Roof pitch is also a consideration- if a roof is too steeply pitched it may be hazardous for solar installers.
An obvious requirement for solar energy is ample access to sunlight. If either the roof or yard is shaded for a significant part of the day, that space makes solar energy impractical.
There are other factors to consider, namely cost, maintenance, and efficiency. As I mentioned earlier, roof mount arrays are cheaper than their ground mount counterparts because of the latter’s need for ground preparation and costly mounting poles to be embedded in concrete underground. Even more cost savings are realized when the system is mounted on a metal roof instead of a shingle one.
Ground mount solar arrays have one additional drawback, which is maintenance. Unless the array is mounted on a cement pad, a costly endeavor, steps need to be taken to keep weeds or grasses from growing up underneath. While these are unsightly, they can also cause problems if they grow up around the panels.
From an overall perspective, it is best to use a roof mount whenever possible. There are many solar kits available online, but I know that Edison Solar has great deals on home solar kits and also will design custom solar kits upon request.