So a solar light is a solar light…right? Well, not really. There are many different types of solar lighting systems using many different types of technologies. The solar lights you find at your local home improvement stores are much different than the ones being manufactured for commercial applications. And depending on what the customer wants to spend on a system or the overall project requirements, the variations can be great.
Commercial Solar Lighting
Solar lights that are in production for commercial applications such as roadways, parking lots, large area security, walkways and pathways, etc. have a higher up front cost but they will pay for themselves almost immediately, especially in cases where the grid is prohibitive or difficult to bring in. These systems provide lighting for specific applications with different operation settings. They also provide many days of stored power to provide continuous reliability for times of inclement weather.
The light power is different as well. Each system is built for the type and wattage lamp that will be utilized for that specific application. Lighting a billboard will take much more power than lighting a small pathway since with a billboard you are typically powering multiple fixtures with a single power assembly; however, on a pathway, each fixture has its own power assembly. These types of projects are also very different from roadway and parking lot applications where lighting levels and operations can be completely different.
That makes the commercially manufactured solar lights more versatile. Every system is manufactured to meet a specification. Lights that need to operate dusk to dawn should be sized accordingly, not for a generalization of 10 hours, something that many other manufacturers are starting to do. Instead, the systems need to be sized for worst case to ensure proper operation year round.
To learn more about proper sizing of a commercial solar power assembly, check out our Solar Lighting Design Guide, a free download. This will help walk you through each step of designing a commercial solar lighting system for almost every application.
Non-Commercial Solar Lighting
The solar lights you can purchase at your local home improvement store are much different. There is still battery storage, but it is small and only has enough power from the amount of sun it received that day and no real backup power. If there is a cloudy day, or many days of rain, the lights will not last as long or may even not come on at all until conditions improve.
For example, I have solar powered rope lights on my back patio. These lights will work almost from dusk to dawn as long as there is enough sun during the day. On rainy and cloudy days they turn off after about 5 hours or less. They also do not provide enough light to even read from; just a faint glow from the 20 LEDs in the rope. For the application I use them for, these are fine, but if you need something that provides lighting for reading, security, or most commercial applications, these wouldn’t work and are not reliable at all. Please note that I know to ensure they have no shading, facing south at a good angle, plus I live in south Florida. These lights wouldn’t operate in the norther areas as well in the winter months.
Warranties are another major difference between the two types of lights. Warranties for commercial lights start at 5 years for specific components and go up from there; however, most warranties for non-commercial lights are 30 days to a year. Since these lights are not meant to last 25+ years in the field, they are not made with the same rugged components as commercial lights.
Therefore, if you are lighting up a driveway or walkway just for markers or environment lighting, smaller, non-commercial solar lights work perfect. If the project requires more lighting for security or large applications, commercially manufactured solar lights are the way to go.
Editor's Note: This post was originally published in September 2011 and has been completely revamped and updated for accuracy and comprehensiveness.