So, you’ve made the decision to go solar. Great! Now you need to get those panels installed. Boring But Important: you need to think how you’re going to prevent them falling on your head.
There are three basic options: on-roof, in-roof, or A-frame.
A-frame first. This is the easiest, and the one that you will see if you ever visit a big PV plant. The panels are supported on rigid galvanised mounts that hold them off the ground.
The main advantage is simplicty. Plus, you can set the panels at just the right angle to catch the sun. Some designs will even allow you to set the panel angle either manually or with a tracking system.
The disadvantages are that you lose yard space, and that panels aren’t good to look at. Also, depending on where you live, security may be an issue.
Security probably won’t be a problem with a roof-based installation, but it gives you plenty to think about.
Firstly, how is your roof aspected to the sun? To catch maximum rays, your panels need to be south-facing, and at quite a high angle. (Your installer can advise.)
Secondly, how is your roof structure? Panels are light, but they’ll catch the wind just like a sail. They need strong mountings.
On-roof is the most common option for domestic solar installations. The solar panel is mounted above the existing shingles. There are many different mounts on the market. Our favorites are the TTI Flat Jacks, which replace whole shingles and attach directly to the rafters — but other systems give good results in the hands of an experienced installer.
In-roof is mostly used for new-build, but it works fine for retrofits, too. The panel takes the place of a run of shingles, with flashings around its edges to keep out the rain. Because the panel is part of the roof, it is more secure — but you need to be absolutely sure of your installer…
One more option has come to market in the last few years — solar shingles! With contemporary manufacturing techniques, it is possible to build solar capabilities right into the shingles, with obvious advantages for the integrity of your roof. With the growing interest in printable electronics, you’ll likely see more of them in the years to come. But, unless you need new shingles anyway, you probably shouldn’t renew your roof right now.