Ground-mounted systems

 

If you have enough space available, you can mount your panels in a specially

engineered rack structure affixed to the ground. In other cases, roofs are

simply too complex, with too many vents and odd angles, to support a large

array of solar panels, so ground mount may be the only option.

Ground-mounted systems offer both pros and cons: On the pro side, you can

orient the panels directly south, at the optimum tilt angle. This ensures the

maximum amount of production over the course of a year. You also won’t

have to worry about leaks in your roof, and the panels are easier to maintain

and change, if the need arises.

On the negative side, ground-mounted systems are more expensive than roof-

mount because they require concrete posts and rigid frames. Wind is also

more of a problem with ground mount. Ground mount systems require suit-

able land space, and the appearance is definitely industrial. You’ll be putting

a big, ugly, visible array somewhere on your property.

Installation considerations

How much you pay for a roof-mounted system depends on the type of roof

you have:

 ✓ Composition roofs: These are the least expensive type to mount to.

 ✓ Flat concrete tiles: These require more work on the part of the install-

ers, and you’ll pay around 5 percent more for a flat tile roof.

 ✓ Spanish tile: These roofs are the most expensive because these tiles

can break and shatter if they’re not treated with kid gloves. Spanish tile

roofs are also prone to leaking, if the installation is not done just right.

The best bet, as far as keeping the panels cool, is to mount them where there

are consistent breezes (although this may be at odds with facing them to the

south). Panels mounted around 6 inches above the roof cool down better

than those mounted directly onto the roof. But this 6-inch height can be ugly;

you don’t want to see the mounting hardware beneath the panels because it

ends up looking “industrial.” So there’s a tradeoff, and the typical mounting

distance is around three inches.

Skirt racks are comprised of a surrounding skirt that hides the underly-

ing rack mount hardware, but this prevents breezes altogether and results

in lower energy yields. But these skirts do look very nice. If appearance is

important, consider a skirt system, but you may end up having to install a

larger system (more panels) to get the energy output you’re looking for. The

return on investment decreases with skirts but the sex appeal increases.