While it may sound bizarre to those who are experienced in the solar industry, sometimes the biggest mistake made in photovoltaic (PV) installations is simply placing the modules in an area that will receive the greatest amount of sunshine in an average day.
You’re probably thinking that shade measurements are easier to pinpoint if the installation is completed in summer rather than winter, but this isn’t always the case. Just as the amount of daylight changes along with the seasons, so too does the angle of shade on a rooftop and this needs to be taken into consideration.
It is also common for home owners to install solar panels in the middle of winter in preparation for the upcoming summer – but if this is the case, how can you go about predicting where the shade will be in the warmer months?
Although a site evaluation doesn’t always guarantee a successful solar installation, it will definitely increase the chances. It can be a key success factor for solar installers and requires up-to-date information on the latest tools and best practices, including shade measurements.
One product that can help to improve the accuracy and efficiency of these site visits is the Solmetric SunEye 210. This handheld tool can be invaluable to solar energy professionals who are completing energy production estimates.
With a unique approach that combines a calibrated fish-eye lens with electronic tilt and compass sensors, the SunEye 210 brings a new level of accuracy and convenience.
“We saw a need for this product because a lot of installers were getting it wrong when it came to installing solar panels on the roof. It may have been completed in summer, and then come winter time when the shading is so different, the panels would be sitting in the incorrect position,” Solmetric technical sales representative John Hardy says.
“Whether it’s a chimney, an aerial or a tree, the SunEye 210 can look up the shadow paths in that area for the entire year. It’s an invaluable tool for installers because they can predict where the shade will be cast onto the roof and therefore judge the best location to get maximum performance from the panels.”
The product works using an integrated digital camera and fish-eye lens that capture an image of the entire horizon in 360°. It will then superimpose the paths of the sun throughout the year based on latitude and longitude and detect shade-causing obstructions, as well as the annual, monthly, daily and hourly solar access.
Armed with this data, the solar installer can make informed design choices about the optimum location for the solar panels – and guesswork or ballpark estimations are replaced with solid data.
“The importance of identifying shade obstructions beyond the day of the installation is critical for successful annual energy production. By using the SunEye’s internal GPS, co-ordinates automatically calculate the annual sun paths for the location,” John explains.
“It is portable and a simple tool to use – the SunEye also comes with an Extension Kit that enables accurate measurements up to 5.4m above ground level. It consists of a telescoping extension pole with a plate at the top to hold the product securely without obstructing the field of view of the camera lens.”
But as John points out, the SunEye 210 doesn’t just make an installer’s life easier while they’re on site – an extra feature can also go a long way to helping you win a tender for a client installation.
In addition to the standard desktop software that is included with the product, Solmetric has also created powerful software for the design of solar PV systems. The PV Designer offers a module layout and shade-adjusted energy production estimates in a complete integrated software tool.
“It has a huge database of modules and inverters. With that information, the program can work out an accurate prediction of the sun’s energy for the year in terms of kW/h, which you can then multiply with the money you will receive from the feed-in tariff,” he says.
“Most installers who buy the SunEye 210 choose to purchase the PV Software as well so they can get a complete package printed out as a PDF for the client. It gives the installer confidence that they’ve done the right thing and reassures the customer that they are getting their money’s worth from the solar panels.
“At the end of the day the SunEye 210 can offer the complete package – it’s definitely a useful tool to keep in the toolbox.”