At Last – Advances in LED Landscape Lighting Combine Energy Savings and Functionality

Orinda News, May 2012

An attractive landscape can be even more appealing after dark with a well-designed lighting system. Aside from accentuating the style and beauty of your home and garden, lighting systems are beneficial for other reasons.

The initial emphasis of adding landscape lighting was for security and utilitarian purposes. Now, it has emerged as a style statement, highlighting your gardens best features at night. Then, there’s the added benefit of extending your outdoor entertaining hours. To meet all these needs, there are various types of outdoor lighting fixtures, each designed for a specific purpose. Some utilitarian lights (like porch lights and path lights) have fixtures that are meant to be seen and can add artistic flare to your garden. Accent lights (like down lights and spotlights) are meant to blend into the landscape drawing your eye to the focal point or space they illuminate.

Incandescent, fluorescent and halogen bulbs have been used as the conventional sources of illumination for decades. This scenario changed with the introduction of more durable and energy efficient options like compact fluorescent bulbs and LED lighting. LED or (light emitting diode) refers to a semiconductor device that is used for conversion of electricity to light. The invention of LED technology can be traced back to the 1920s, however, it’s practical use started in the U.S. during the 1960s. Early versions of LED lights produced low intensity red light mostly for electronic instrument panels.

In the late 1990s, LEDs expanded to more common household lighting and most recently to landscape lighting. On the surface, they sounded great. They use about one third the energy of other bulbs and were said to last up to 20 years. What could be better? The reality was less rosy. The majority of the outdoor LEDs failed to live up to their promises. The D.O.E. (Department of Energy) launched a testing program “Caliper” that put these products back on the testing block. The results were staggering; nearly every product failed to live up to its claims. Some LED manufacturers faced lawsuits because their product capabilities were so abysmal when compared to their promises.

Up until about the middle of 2011, we felt that LED lighting fixtures were not reliable enough for outdoor use. Our first experiences using LEDs had less than desirable results compared to incandescent or halogen lights. The light quality was not as good, output was inconsistent, and the warranties on the LED lamps didn’t match-up with its other components. For example, the lamp itself guaranteed 30,000 hours of burning time while the fine print listed other parts (drivers, transistors and connectors) at less than 10,000 hours.

The basic problems with early outdoor LED technologies were low light with little spread, overheating, susceptibility to moisture, poor color and unreliable fixture integrity. LED circuits are very sensitive bundles of electronics. Think about it – would you put your cell phone in a leaky box then plant it in your back yard and expect it to last 20 years? It’s not easy to manufacturer a sensitive piece of electronics that will survive the worst Mother Nature has to offer.

We were convinced (up until recently) that LED lighting was just another passing fad much like the fiber optics of the 1990s. Change does happen however, and as new LED technologies evolved and improved in the lighting industry these enhancements eventually trickled down to landscape lighting products as well. Today, there are good products on the market for new installations as well as retrofitting options for older lighting systems.

The newer LED products offer more flexibility in beam-spread (lighting area capacity) better light output (intensity), and improvements in the color the lamp emits. Using an “integral module approach,” the fixture manufacturers have designed the entire lighting unit to be better suited for an LED source. This was accomplished by improving heat dissipation to keep the fixture’s temperature in optimal range, providing for a wide range of voltage variation, protecting the driver/board from voltage spikes or surges, filtering electromagnetic interference and, most importantly, sealing (or potting) the circuit board to eliminate moisture interference with electronic parts. As technology advances, some newer LED fixtures are even designed with the ability to replace just the module.

There are a few factors to consider when purchasing LED lighting and these tips will help you choose the right products for your project. The first consideration is lumen output. This measures the intensity or brightness of a light. One early criticism of LED lighting was that it was not bright enough. In many cases, this criticism was well founded. In fact, it can still be an issue with many lower quality LED lighting products.

When choosing an LED landscape light, it’s important to be sure it will produce enough light for your application. Yet when told that a particular LED light produced 200 lumens, it probably wouldn’t mean much to you so we’ll use a common incandescent light bulb as a benchmark. Most people are familiar with the amount of light produced by a standard 60-watt incandescent bulb. A 60-watt bulb equates to about 850 lumens of LED light output. This should give you a general idea of light output when expressed in lumens.

The other important factor to consider is the color the light emits. Color of light is expressed using what’s called color temperature and is measured by a term called kelvin. A light source with a higher kelvin or color temperature (5000K or more) is considered “cool” and produces a bluish light. Light sources with a low color temperature (2700-3000K) are considered “warm” and produce a light that is more yellow in color. The typical incandescent light has a warm color temperature of about 2700K while a fluorescent light has a cooler color temperature, in the 4800- 5000K range.

When you’re shopping for LED landscape lights, be sure to select an LED lamp that has a color temperature suitable for your application. Choose a higher kelvin for task lighting (cooking spaces), a medium kelvin for safety lighting (walkways, steps and entry areas) as well as entertainment spaces, and a lower kelvin for special effects (lighting focal points such as trees, shrubs, water features, statuary, etc.). Increase the kelvin for larger objects like oaks or other large specimen trees. Several manufactures also include multiple colored lenses with their fixtures to allow you to achieve the best color effects.

The last consideration is cost. Whether you’re installing new fixtures or retrofitting your existing landscape lighting, LED lamps cost about 25 to 50 percent more than traditional low voltage lighting bulbs. Keep in mind that this will be somewhat offset by lower energy use, reduced cable and transformer size (which translates to lower installation costs), and extended product life span which will reduce ultimate repair and replacement costs.

Is led right for all applications? Not yet. Many contractors, ourselves included, prefer an integrated approach to landscape lighting using LED for path lights, small trees, rocks, and in hard to access locations combined with traditional 12-volt lighting for bigger items like mature Oaks and other large trees. LED lighting will not eliminate the need for system and fixture maintenance like cleaning lenses of debris and mineral build up and occasionally refocusing (moving and re-aiming lamps).

Green is good and so is solar, but it’s not a good option for powering an outdoor lighting system, not yet anyway. The concept of solar fixtures, (renewable energy with no wires or transformers) plus easy installation is just not practical. Generating enough solar power would require intense sunlight all day, which would at best only provide enough energy for a marker light and very little ambient or usable light.

The tiny, 1-inch solar cell and battery on top of the common lighting fixtures sold at big-box stores simply isn’t large enough to gather and store the power required for efficient nighttime use. To generate enough solar power to operate an entire outdoor LED lighting system, a large collection panel would need to be installed in the appropriate location along with a high quality battery. This would be a cumbersome approach and unattractive solution to low energy outdoor lighting.

While not every “green idea” has great result in every application, we are all obliged to do the research and find earth friendly solutions that work for our customers.

For more information about LED and outdoor lighting systems, email us at [email protected].