The worst thing about expanding a parking lot isn’t pouring the extra cement – it’s digging up the cement you already have to wire more light poles out there.
You can’t skip the illumination – doing so is an obvious safety hazard – but you may not need to trench underground for your wiring. Solar-powered outdoor area lighting is making slow inroads in the market. Is it right for your building?
Pros and Cons
The key appeal of outdoor solar lighting is its self-contained nature. Systems typically don’t incorporate electrical wiring, eliminating the need for trenching in the middle of existing parking lots and other finished spaces. This aspect appealed to ATTC Manufacturing, which added pole-mounted solar lighting to the parking lot in front of its Tell City, IN plant to compensate for growth that more than doubled the size of the building. Plant managers also worked with the Indiana DOT to add the same models to a state access road leading to the building.
“They were expanding the parking lot and would have to trench wire underground to put up standard lights,” explains Shawn Tefft, solar lighting specialist for SEPCO and project manager on ATTC’s solar area lighting installation. “They also wanted to put a green foot forward for clients.”
Some models have a simple solar panel at the top of the pole, while others resemble regular poles wrapped in solar film, adds Scott Tapia, sales manager for southern California at ABM, a maintenance and facility services provider.
“We’ve used solar area lighting for applications like mailboxes for homeowner associations or kiosks with motion sensors,” says Tapia. Other buyers include military bases and parks. “They tend to appeal to customers who want to light up parks or roads that are too far away to wire.”
Shop Smart for Solar
The solar component adds a cost premium to the lights, but the lack of wiring and the ability to leave the existing parking lot untouched saves on installation costs, helping keep solar lights competitively priced in many areas, Tefft says. To make the most of your purchase, also take into account these two factors.
Existing lighting: Adding new poles to your existing outdoor infrastructure means you’ll need to match their brightness and distribution as closely as you can. This can be a potential hurdle to implementation, explains Tapia, who also recommends setting aside questions about trenching and PV panels at first and focusing on the details.
“Look beyond the solar aspect and learn about the driver in there,” Tapia says. “Who’s manufacturing the LED chips? What distribution does this fixture have? What will the light level be? Those are key factors in making a smart decision on any kind of LED product, whether it’s powered by solar or electricity.”
Storage: All solar-powered outdoor lighting has some kind of storage, but you’ll need to account for your location and typical weather patterns when specifying just how much storage you’ll need.
Vendors may also refer to this as autonomy – in other words, how long your lighting can run without being recharged by sunlight.
“As a rule of thumb, the further north of the Mason-Dixon Line the building is located, the more days of autonomy you need,” explains Tefft. “Five days is the minimum – usually that will be enough south of the line, but even in some southern states there are lower sun hours and a lot of overcast days in the winter.”
Janelle Penny firstname.lastname@example.org is senior editor of BUILDINGS.