Do-it-yourself outdoor lighting
A fan of low-voltage residential lighting, I use it in my landscaping and gardens as well. A big advantage of low-voltage lighting is you can install it yourself and eliminate professional installation expenses. There is a huge variety of styles available at most home centers and hardware stores.
Another related advantage is safety. With low-voltage lighting, the wires on the ground carry only 12 volts. You will not be shocked if you accidentally nick one while working in the garden.
The energy efficiency of low-voltage lighting is fairly similar to standard line-voltage (120 volts) outdoor lighting. There may be slightly more electricity used because of transformer inefficiencies and higher current in the wiring, but it is not a significant difference for most systems. If you are interested in brightly lighting a large area, line-voltage lighting fixtures, such as low pressure sodium, are your most efficient choice.
The newest and most energy efficient low-voltage landscaping lighting uses super-efficient LEDs (light emitting diodes) instead of standard incandescent bulbs. This type of lighting technology is becoming more common even for standard indoor lamps.
LEDs are still considerably more expensive than other lighting alternatives, but they use less than one-fifth as much electricity as equivalent incandescent bulbs. They also last at least 10 times longer. The light from LEDs is more directional than from incandescent bulbs, so multiple LEDs are often used inside one fixture for broader lighting patterns and brightness.
Each low-voltage LED fixture may use as little as one watt of electricity compared to about 11 watts from a typical snap-in, wedge-base, low-voltage bulb. Some of the brighter fixtures, such as bollards, use a two-watt LED, and floodlights use three LEDs. The light quality from LEDs is very white and pleasing.
The most difficult part of installing a low-voltage lighting system is making sure the total wattage of the all 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, and the instructions for the fixtures should list their 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, be careful not to 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 purchasing a low-voltage system or the components to put your own system together, select a transformer with a built-in mechanical or electronic timer or photo-eye control. These are common in many kits. With a timer, there is no chance of leaving the lights on all night and wasting electricity.
The most convenient are photo-eye controlled transformers. With a standard mechanical timer, if the electric power goes off temporarily, the timer motor also stops so the on/off sequence will be incorrect and need to be reset. A photo-eye control has many sequencing options. One of the more convenient and efficient is "on" at dusk, "off" in a set number of hours (six, eight, etc.).
To edge a path, snap-together lighted plastic simulated bricks are effective. The electrical connectors are built into the bricks so you have to run wiring to only the first brick along the edge. To light a deck, several decking material manufacturers offer built-in post and baluster lights with hidden wiring.