The Solar Pathfinder would have lost our pick for Editor’s Choice to the ASSET if it weren’t for the new version that comes with ‘pathware’ software. - Instant On-Side Estimate. The SolarPathfinder is really the standard shade analysis tool. Using a grease-pen, you can trace out the shade lines. This may sound a little too old-school for some of you, but the advantage is you have an immediate, on-site estimate of how the solar panels are going to perform in any given spot. For a more detailed shade analysis, take a digital picture of the Pathfinder on-site and upload it to your computer. This allows you to utilize the new "Pathware" software that comes with the Solar Pathfinder unit these days. The best part about this is you don't even need to be connected to the internet to use the software, which means you can get a very detailed shade analysis on-site if you bring a laptop.

The Wiley Electronics ASSET - Acme Solar Site Evaluation Tool - is the top-of-the-line, all-bells-and-whistles, deep-pockets shade evaluation tool. At a price tag near $600 it is for the serious solar field rep or installer - not the DIY homeowner. But if you can afford it and do more than a few solar power site evaluations per week this unit will pay for itself quickly by saving you a lot of time. Unlike the Solar Pathfinder, the ASSET has a built-in digital camera. It is fairly simple to get the hang of: use the built-in level to position the device, align it to the south, adjust the tilt to the desired degree, take seven pictures at pre-determined intervals for a panoramic effect, and download the pictures to your computer for automated software analysis. The fact that, currently, only certain approved dealers sell this product ensures that the price isn’t going to go down much any time soon, even on used devices.

Solmetric’s SunEye is a great shade analysis tool, but for the price it would not be one of our suggested buys. This unit does include a built-in digital camera and sophisticated analysis software. But it does not come with a hard-case (extra $95) or the GPS ad-on that helps you get the full functionality (another $300) and costs $1400 itself. To end up with the kit you'll need the price is going to be around $1800, plus taxes and shipping if applicable. You'd have to save an awful lot of time in the field to pay for that, and we couldn't see how this unit would save you any more time than the Wiley ASSET - or the tried-and-true Solar Pathfinder for that matter.