With the shortest days (and longest nights) of the year in the northern hemisphere, December tests the limits of solar lights. For many areas, like the Pacific Northwest where First Light headquarters is located, this time of year is combined with prolonged wetter weather for an even greater challenge.
Fortunately, there are approaches to get lights to work through the night regardless of inclement weather and shorter days. But the two main approaches offer significant differences in performance and cost.
Traditional Solar: Modelling Worst Case Scenarios
Traditional solar lights deal with challenging solar conditions by designing and building systems based on assumptions of worst-case scenarios. The longer the nights and the more days of rain expected, the bigger the solution will need to be. It will require bigger solar modules to capture more energy, bigger batteries to store enough energy to get through longer nights and bigger frames and poles to hold it all in place.
And despite the best planning, there is still no guarantee that conditions won’t fall outside assumed worst case scenarios. This is a significant drawback because the performance of traditional solar lights is locked in. When conditions fall outside of the assumed worst case scenario, the lights will fail. Conversely, when conditions are ideal for solar, these static systems can’t take advantage of the more energy available. It will provide the same amount of light with the energy available in December as it will in July.
These bigger systems also come with greater costs. Materials will be more expensive as will a thicker pole to handle increased wind load requirements. This is in addition to a more complicated install requiring more people and equipment. The batteries alone for these kinds of systems can be over 100 lbs.
Self-Contained Solar: Adapting to Real-World Conditions
One of the most common questions we get is if our lights can last through the night. The reason we can confidently answer yes is because we’ve engineered our lights with a number of features so that they remain reliable regardless of conditions while also maximizing performance and reducing cost. Three of the most important features in this regard include adaptive capabilities, a variety of lighting profile options and better batteries.
Locking in performance based on a presumed worst-case scenario presents risks in terms of reliability and misses opportunities to take advantage of good conditions. One of the major advantages of First Light self-contained lights are adaptive capabilities that allow each light to predictively adapt to actual installation conditions. This allows our lights to maximize lighting performance and reliability, far beyond any statically modelled system.
When it comes to performance, the most important aspect is delivering effective light for safety or security when users are present. This means that light all night, while necessary for some situations, is not always the best option. It contributes to light pollution and wastes energy unnecessarily when there are no users or a facility is closed.
Self-contained solar lights allow you to choose from a variety of lighting profiles to maximize light when it is actually needed by users. When combined with motion sensing and adaptive capabilities, self-contained lights shine as bright as possible during the times it is needed most.
While highly energy efficient LEDs have greatly improved the performance of solar lights over the last decade, the more recent innovation has been the introduction of lithium batteries. Compared to lead acid batteries that are used in most traditional solar lighting solutions, lithium offers a number of advantages in terms of performance and reliability.
In addition to being smaller, one major advantage of lithium batteries is that they can handle being partially charged much better while not affecting lifetime. This is significantly different than lead acid batteries whose useful life is significantly impacted when partially charged for even short periods of time. This is a critical capability during darker times of the year when batteries are often not fully charged.
The result is that lithium batteries have significantly longer expected lifespans of 8 – 10 years rather than 2-3 years with lead acid. This means that lights have much better reliability, can be self-contained and are much easier to install resulting in lower costs.
The Next Generation of Solar Lights
Providing effective light when it’s most needed is the key to better, simpler solar lighting. Combined with better technology, self-contained solar lighting is able to deliver reliability and optimal performance throughout the year, including during the darkest days in the winter.
To learn more about how we ensure reliability in our lights, check out our technology page.