What you need to know about shading assessments with solar lighting
Most solar lights are designed to perform in locations where they’re exposed to direct sunlight all day, all year round. Orca Solar Lighting’s Jamie Janides looks at ways to ensure optimal performance if there happens to be any shade.
To ensure optimal performance, every solar light location needs to be checked for shading via a shading assessment before installation. Without a comprehensive shading assessment, you risk installing lights that fail, jeopardise safety, severely compromise battery life and need constant repair and servicing.
This article covers what you need to know about shading, a shading assessment and workarounds for coping with shade so you can be certain your solar lighting installation will provide reliable and constant light all year round.
How is shading assessed?
Location and surroundings assessment
Shading assessments ensure that every solar light’s location is checked for shading and assessed for when the sun tracks lower to the north in the middle of winter.
Shading assessments are vital to make sure each solar light is set at the optimal power model setting to allow for varying amounts of shade.
To select the correct power model for any location, your lighting provider should use accurate weather and solar radiation data, work from Google Earth Street View, and use any site photos and videos provided by the customer. Alternatively, your solar light provider may also conduct a site visit to establish the amount of shade at each location.
During a shading assessment, any shading from buildings, structures and fences to the north, east and west are accounted for. Current and future shading from shrubs, trees and bushes in proximity to the solar lights must also be factored in.
Selecting the right power model
For most of mainland Australia, the most challenging time of year for solar lighting is during mid-winter when the nights are the longest, the days are the shortest and the shadows last the longest due to the north low tracking sun. The winter months are used as the basis for selecting the right power model for these locations as this ensures the solar lights are set up for the worst-case scenario, that is, the highest amount of solar energy each solar light can capture during the shorter daylight hours.
In the tropical northern locations of Australia however, the most challenging time for solar lighting is during the summer cyclonic months. To cope with the cyclone season, these locations can often demand more autonomy from solar lights (battery back-up), however, the power model and battery back-up required are based on relatively short night time lengths in comparison to the longer winter nights in mainland Australia.
Heavy shading workarounds
If heavy shading is across much of a site, solar lighting may well not be an option. However, in situations where some solar lights will be installed in heavy shade locations, the light pole can be powered by a solar ‘slave’ pole which has the solar panel and battery located in a shade-free location, with a low voltage cable trenched and cabled to the light pole in the shade.
When it comes to shading assessments and any slave pole planning, working with a highly experienced solar lighting company is recommended. This will ensure the location of each solar light is properly assessed so that solar panels receive direct sunlight all day, all year round or measures to enable the solar lighting to cope with shade (including different power models and any slave poles) are set up to provide reliable and constant all night light.