A: The big advantage of low-voltage lighting is you can install it yourself. There is a huge variety of styles and accessories available at nearly every home center and hardware store.
Another advantage is safety using metal garden tools. Many gardeners accidentally cut through wire insulation while working. Because the wires on the ground carry only 12 volts, you will not be shocked if you nick one.
The energy efficiency of low-voltage lighting is similar to standard 120-volt outdoor lighting. Slightly more electricity may be used, but it is not a significant difference. If you want to brightly light a large area, line-voltage lighting fixtures, such as low-pressure sodium, are the most efficient.
The most efficient low-voltage landscaping lighting uses LEDs instead of standard incandescent bulbs.
LEDs are still considerably more expensive than other lighting alternatives, but they use less than one-fifth as much electricity as equivalent incandescent bulbs and last at least 10 times longer. LED light is more directional, so multiple LEDs are often used inside one fixture for broader lighting and brightness.
Each LED fixture may use as little as 1 watt of electricity compared with about 11 watts from a typical snap-in wedge-base low-voltage bulb. Some brighter fixtures, such as bollards, use a 2-watt LED, and floodlights use three LEDs.
The most difficult part of installing a low-voltage lighting system is making sure the total wattage of all of the fixtures on a line does not exceed the rated output of the transformer. The maximum 12-volt output wattage will be listed on the transformer. Instructions for the fixtures should list individual wattages.
If you buy a prepackaged low-voltage lighting kit, it will include the proper size transformer for the number and types of lights. If you add more or assemble your own lighting kit, do not exceed the transformer’s output maximum or ever go above 300 watts. If a lighting layout requires more than 300 watts, do not connect two transformers together. Set up two separate wiring layouts to stay below 300 watts on each.
When buying a low-voltage system, select a transformer with a built-in mechanical or electronic timer or photo-eye control. These are common in many kits and easy to find.
With a timer, there is no chance of leaving the lights on all night and wasting electricity.
For general lighting where the fixture is not noticeable, inexpensive plastic fixtures are fine. For more exposed areas, decorative metal fixtures with stained and etched glass are attractive.
The following companies offer low-voltage lights:
Troy Landscape Lighting