Hardscapes Gallery
Solar Power in the Landscape

by Marcia Passos Duffy
Innovations in lighting

Photos Courtesy of Sol, Inc. Walkway lighting in Chicago, by the Chicago River.

Solar-powered lighting in the landscape still has a bit of an image problem, which experts in the industry say is chiefly equated with those small, off-the-shelf lights with a stamp-size solar panel that barely give off enough light to make it worth the inexpensive price tag.

Commercial-grade, solar-powered LED landscape lighting is in a different league, and advances in technology are making it a viable alternative to low-voltage landscape lighting. Commercially available, solar-powered LED lights give more output than those found in discount stores, and, if done right, are indistinguishable from low-voltage lighting in terms of power and longevity.

 “A professional landscape lighting system does not work with individual lights with little solar panels ... that’s not strong enough to charge up a battery to give enough light. The only way you can get light similar to low-voltage lighting is by using powerful solar panels,” said Geoffrey MacMurdo, owner of Sun Solar Products of Medford, N.Y., who has been in the solar lighting and energy business since 1976; his company, located on Long Island, is a dealer/distributor of solar energy and lighting products for the New York metropolitan area.

Using large solar panels to get reliable bright outdoor lighting is not new, in fact, the United States military has been using solar lighting for years in Iraq and Afghanistan. “Large solar panels have the capacity to last all night with a five to 10-day battery backup,” said Bryan Blazie, director of sales engineering for Sol, Inc. (www.solarlighting.com) of Palm City, Fla. The company develops, manufactures and markets commercial/ industrial-grade, solar-powered lighting systems for a wide range of lighting applications. It is the largest supplier of solar lighting systems to the United States federal government, and its products are used by universities, large corporations and municipalities for lighting roadways, parks, monuments, pathways and signage.

Technology takes a leap

The biggest leap in solar technology improvement in the past year has been due to the advances in LED bulbs.

“There has been a major jump in the past 12 to 14 months,” said Blazie. “LED efficiencies have been climbing for the past three years, but now they are brighter, more efficient than ever. The advances have been brought on by the interest in environmentally green technologies,” said Blazie, who expects LED efficiencies to continue at 15 to 20 percent more output in light and brightness every year.

Now that LED bulbs are more efficient, it takes less energy to power them, therefore making solar technology easier to power, for a longer time. This opens the door for commercial-grade solar lighting to go mainstream, particularly in the landscape.

An example of solar LED signage lighting.

“Our phone has been ringing off the hook,” said Blazie, noting that inquiries have increased 100 percent this year. The account manager for Sol, Inc.’s domestic sales, J.R. Finke, attributes the jump to directives by federal, state and local governments to reduce energy consumption; corporate America has also hopped on the bandwagon to reduce its carbon footprint. “We’ve been in business a long time, and in previous years people were not [as] aware of renewable technology as they are now,” said Finke.

In the landscape, the interest fueling solar lighting has primarily been in public walkway lighting for bike trails, footpaths, playgrounds, parks and other areas. “A landscaper can light a walkway without trenching for power. You plant a pole, the panel is placed on top of the pole, aim it south, and you’re done because everything is self-contained,” said Blazie. Landscapers have also been requesting information for floodlights and sign illuminators.

Of course, it takes the right system to make enough power, Blazie pointed out, including significantly sized solar panels (the smallest Sol, Inc. system uses 40 watts of power; larger systems go as high as 400 watts). Backup systems are the size of a car battery. Each system is sized specifically to the area where it will be placed. In Florida, the systems are slightly smaller than places with more cloud cover, and/or less winter daylight, such as New England. Solar lighting systems are sized for the worst months of the year, usually between December and January in most places in North America.

Solar panels must be placed in direct sunlight and cannot be shrouded by a building or shaded by trees.

There are advantages to installing solar lighting in the landscape. “The biggest advantage of having solar lighting is that you don’t have to run power to it,” said Blazie, noting that the cost of trenching can be expensive. Once the money for a solar light is invested, the property owner doesn’t have to pay for electricity for the lights. LED bulbs can last 100,000 hours (about 20 years) running 12 hours a day.

The initial cost of solar power is still enough to make some customers pause. A single fixture could start at $800 and go up from there. By contrast, a similar grid-tied light would cost about $300. However, some states have a rebate from utility companies for using solar; there are even state and federal rebates.

The darker side of solar

Solar lighting cannot run without the obvious: sunlight. Solar panels must be placed in direct sunlight and cannot be shrouded by a building or shaded by trees. While it makes sense to use solar lighting in places where it is too expensive to run electricity—usually places where there are a lot of trees—landscapers need to assess if there is enough sunlight to power the solar panels.

Landscapers can light these areas with solar if the panel is put in a separate location, but then there’s the cost of the solar energy system, plus the cost of trenching wires for the lights.

“If an area has low sun hours with a lot of trees, or is in the shadow of a mountain, there’s not much we can do,” said Finkle. Sun hours can be calculated by consulting the U.S. Department of Energy or NASA, which calculates the sun hours for every location on Earth, but even in low sunlight, the system can be “sized up” to work. While it may defeat the purpose of installing an entirely off-the-grid system, a solar lighting system can be connected with on-grid AC power to charge the battery in case of a long stretch of inclement weather.

Another disadvantage is that the equipment to power up a solar lighting system is larger than standard grid lighting; and it will be obvious that the lights are powered by solar. There is usually a large solar panel and a battery box (typically hidden by the panel).

Solar makes a statement

Making it obvious that a municipality or corporation has “gone solar” may not be a bad thing, Finkle said. “Solar energy is a thing of beauty and a source of pride ... to see a solar array means you’re not just talking the talk, you’re actually doing something. Solar energy is not just fashionable right now, but it deals with a serious issue.”

While the price point is high, with most professional-grade lighting being purchased for commercial or public properties, sales of solar lighting in the landscape have also jumped for homeowners, said MacMundo. “You would think this would be popular among wealthier clients, but that is not what I’m seeing,” said MacMundo of his sales territory in metropolitan New York City. “People are doing this not only to save money [on utilities], but to save the earth for their kids ... people are sincerely trying do their part to help turn this mess with global warming around.”

The author is a freelance writer from Keene, N.H.