One of the leading manufacturers of solar site assessment technology announced the release of a new version of its product today: the Solmetric SunEye 210 is now available, ladies and gentleman of the solar industry. If you’re not thrilled to your fingertips, Gentle Reader, it’s probably because you’re not a solar installer; but if you’re curious about why this is such an important element of the install process (and to get more product details), read on.
Perhaps the single most important piece of site assessment for a solar installer is shade evaluation. Will that big oak tree thirty feet away from the house ever cast shade on the roof? During what hours of the day will shade from the chimney fall across the roof’s southern exposure? What kind of a shading issue will those pine trees present in winter, when the sunlight will come in at a lower angle? There are numerous tools on the market that solar installers can use to evaluate sun angle and shade factors.
The one essential tool is the Solar Pathfinder: cheap and utterly reliable if used correctly, the Pathfinder uses a convex mirror to reflect a panoramic 360 degree view of its location onto a longitudinally-specific chart that plots the hours in the day against the months of the year. So if you set it on the part of a roof where a solar panel might go, you can see exactly what will be shading that location, and when. The installer essentially traces the reflection to keep an accurate record of when obstructions visible in the reflection (trees, buildings) will be shading the site in question. Here’s a visual for you, but check out Pathfinder’s “How it Works” page for more info.
Left: Solar Pathfinder; Right: Sunchart diagram
You can scan the traced diagram into a computer with Pathfinder’s software, but for some solar installers, having immediately accessible data is worth a premium. So they use tools like the Solmetric SunEye, which essentially replicate the Solar Pathfinder’s technology but digitize it on site.
In fact, the SunEye digitizes the data in the palm of one’s hand using essentially digital camera technology: the SunEye is a hand-held device that has a small fisheye lens that’s basically a mini-Pathfinder, plus a screen on which what the lens “sees” is projected as user-friendly charts and data. It’s also got integrated GPS technology so you don’t have the manually adjust for true south as you do with the Pathfinder. Doing so is not difficult for the experienced solar installer, but it’s a step many are just as happy to skip if given the option.
The SunEye’s software options includes a PV design option to facilitate module layout, and lets installers manipulate data into different files formats. This “PV Designer” software also allows for basic predictions of energy outputs.
So yeah, pretty fun stuff, and cuts out a bit of manual (er, intellectual?) labor for the solar installer. But here’s the catch: the Solar Pathfinder, which gives an installer all the data he or she needs in order to correctly design the most efficient solar panel installation for a given site, retails for about $300. The Solmetric SunEye, which adds some fun bells and whistles, offers an iPhone app (Solmetric IPV) for the relentlessly tech-enabled, and offers some variant outputs, retails for about $2,000–nearly 6.5 times more expensive than a tool that also gets the job done. Small-shop operators are probably better off sticking with the tried, true, and affordable Pathfinder, but for those who can budget around it, the SunEye is the best kind of toy: fun and educational.
