Introduction

All over the world, lighting is undergoing a revolution. For many decades, most people have used incandescent bulbs, which burn out and need to be replaced frequently. They also use a lot of energy, racking up your power bill. Today, however, many are switching to LED light bulbs, which are far more efficient and longer lasting. A typical LED can last 10-20 years and use five times less electricity for the same brightness. Manufacturers keep improving their color and warmth, making them more adaptable and comfortable. As their prices drop, the savings over time from switching to LEDs also keep adding up. A lot of lighting in homes and offices has switched over to LEDs, and perhaps you already have too.

Many yards, gardens, and other small outdoor areas also use a lot of lighting for safety and attractiveness. Switching to LEDs also makes sense for saving money and energy, but can be complicated by details. Inside the home or office, switching over can be as simple as buying a LED bulb at the store and plugging it into your existing lamp. But outdoor standards for wiring, lighting, or even socket type can vary from place to place or even within a yard. Making the best use of LEDs in this situation might call for changes in layout or other details. All this can be confusing and daunting if you’re doing it for the first time.

Actually, all the components and knowledge needed to convert your landscape lighting to LEDs are out there; they’re just not as standardized or readily available sometimes. This is where we come in. Whether you’re a DIY homeowner looking to spruce up your yard or a gardener or landscaper offering an extra service for your clients, we’re compiling what you need to know to start or upgrade your landscaping with LED lighting.

Bulbs

Picking the right lights to fit your space and your budget is critical. Understanding a few key specifications can help you decide which lights are right for you. The amount of electrical power a bulb uses is measured in watts (W), while its brightness is usually given in lumens. For example, a typical 40 W incandescent light gives off about 450 lumens. The larger the space or the more intense the light you want, the higher in lumens you’ll want to go, while your electricity bill will depend on the wattage. Depending on the available electrical wiring in your space, the voltage the light requires will also matter. Finally, for illuminating wide spaces, chip-on-board (COB) LEDs can be helpful. These are basically multiple LEDs on a single panel, enhancing the brightness and viewing angle.

There are lots of outdoor LEDs for sale, so to help you pick, we’ll break down a few of the most popular ones to see how they suit your needs:

Zuckeo Landscape 3W LED light (https://www.amazon.com/ZUCKEO-Landscape-Spotlight-Voltage-Water-resistant/dp/B072N6YBNZ)

Lumens: 300 (100 lumens/W)

Price: $38.99 / 4 lights ($9.75 per light)

Price per lumen: $3.25 / 100 lumens

COB: Yes

This COB LED offers a warm, bright white light and uses 12-24 V. It is water resistant and suitable for yards, patios, decklights, or in-ground lighting. The small, short wires are easy to bury if desired, though their fineness can make them easy to break when stripping them. Wire nuts or electrical tape are needed to connect the bare wires to power source. The aluminum finish reduces fading and heating under sunlight.

Lemonbest 5W COB LED (https://www.amazon.com/Lemonbest%C2%AE-Outdoor-Decorative-Lighting-Landscape/dp/B012VLSYJE)

Lumens: 350 (70 lumens/W)

Price: $17.96 / 2 lights ($8.98 per light)

Price per lumen: $2.57 / 100 lumens

COB: Yes

This warm white light uses 12 V (AC and DC converter compatible) and is suitable for gardens, walls, and path lights. The aluminum casing doesn’t flake. The thin wires (around 18 gauge) have no connectors and need the use of wire nuts or electrical tape for connections. It comes with a metal mounting spike, though the screw holding the light is difficult to reach.

GLW 10 W 12 V AC or DC warm white LED (https://www.amazon.com/GLW-Waterproof-Outdoor-Halogen-Equivalent/dp/B008XZAQDU )

Lumens: 750 (75 lumens/W)

Price: $11.99 per light

Price per lumen: $1.60 / 100 lumens

This waterproof outdoor light is equivalent to an 80 W halogen bulb and can be used as a flood light. The wiring is short and you may have to strip some more wire to make good connections. It is useful to tighten the screws before installation to ensure that the light stays watertight.

Paradise 5 W LED floodlight (link?)

12 V landscape lighting

220 lumens

44 lm / W

Pool Supply FX Luminaire PB 3LED wall washlight (https://www.poolsupplyunlimited.com/fx-luminaire-pb-3led-wg-wall-wash-light/146872p1)

1 white gloss I PB-3LED-WG $148.72

Wiring

Inside the home or office, hooking up a light or appliance to electricity is mostly as simple as looking for the nearest outlet. Indoor electrical wiring is standardized and mostly hidden away behind walls and under floors. However, finding and making the right connections outdoors in yards or gardens can be more complicated. You may need to put down your own wiring in order to place your lights where you want them. Doing so safely and effectively requires understanding some basics about different kinds of wires and their compatibility with the lights you end up using.

In the US, electrical wires are categorized by their AWG (American wire gauge) number, which describes the wire diameter. Wires with larger AWG are thinner and have more resistance. Each decrease of 3 in the AWG corresponds to about a doubling of the wire cross section and halves the resistance. Conversely, each increase of AWG by 1 increases the resistance by about 25%.

Both copper and aluminum wires are widely available; the latter are cheaper but also about 60% more resistive. As a result, for the same length, an aluminum wire will have about the same resistance as a copper one with a AWG larger by 2.

As a reference, this table gives the resistance per foot and corresponding resistances for 5 and 50 ft wires for AWG from 10 to 18. Also listed is the voltage drop across the wire assuming 1 A current is flowing.

What wires work for you depend on the situation. The most important requirement is that it be able to safely handle the power your light demands. For longer distances, smaller AWG wires are necessary.

Wires

12/2 low voltage landscape lighting cable wire

Length: 100 ft (direct burial), copper

Price: $49.95

Southwire 14/2

Length: 100 ft

Price: $37.21

Sunlight resistant, suitable for direct burial. Can be used for path lights, outdoor spotlights, and garden accent lighting

UL listed, CSA certified, RoHS compliant, Greenspec approved

Temperature rating: -40 F to 140 F

Southwire

16/2 low voltage lighting cable

Length: 100 ft

Price: $30.23

Has a water-, dust-, and dirt-resistant vinyl jacket, sunlight resistant, suitable for direct burial

Southwire 12 AWG 2 conductor

Price: $53.97

Transformers

If your yard or space isn’t already wired for lighting, or if you want to add or change the location of lights, you will need to run new lines out to the lights. Typically, outdoor lights use low voltage (such as 12 V) for safety and efficiency. By contrast, standard electrical outlets in the United States output 120 V. Therefore, if you run wires from outlets in your home, garage, or yard to your lighting system, you will need to use a step-down voltage transformer. To choose the right one for your situation, you should consider how much power your system is going to use, since transformers are rated by their output voltage as well as the amount of power (in watts) they can supply. Here, the efficiency of LEDs is a big advantage; since LED bulbs typically use a fraction of the power that conventional lights do, you can support many more lights with a given power budget or alternatively use a lower power transformer, which can add up to big savings. You can estimate the required power level by adding up the watts used by each light you plan to install and comparing it with the transformer power rating.

Weatherproofing and safety are also important considerations for choosing the right transformer. Waterproof transformers can be safely installed outdoors so that rain or other moisture won’t lead to accidents, but usually cost more. Alternatively, if you can install the transformer indoors or inside a garage or shed and run wires outside, less expensive non-waterproof equipment can work just fine.

As an example, the Chanzon DC converter LED driver lighting transformer makes for a low cost but powerful option at $15.85. It takes standard 110/220 V input and outputs 12 V, supporting up to 5 A current and 60 W in our experience. Many outdoor LED bulbs use about 5 W, for instance, so this transformer can power up to 12 lights. It is not weatherproof but is easy to install to an outlet within a garage and run wires outside. It is “low fever,” so it doesn’t run hot, and doesn’t make noise, and comes with a 2 year free replacement guarantee.

If you need more power to support even more or brighter lights, several options are available.

200 W Hero LED PS-WP 12LPS200 LED power supply ($59.95) (https://www.amazon.com/HERO-LED-PS-12LPS200-DIM-ETL-listed-Dimmable-Constant/dp/B015FH1HLS/ref=sr_1_1?ie=UTF8&qid=1529167910&sr=8-1&keywords=12LPS200%2BLED%2Bpower%2Bsupply&th=1)

Amazon link is dimmable. Use a dimmer (139.95)?

Moonrays Electric Power Pack Low Voltage Lighting for outdoor use with light sensor and rain-tight case (200 W) ($62.99)

(https://www.amazon.com/Moonrays-Electric-Voltage-Lighting-Rain-Tight/dp/B002PN4Z8S/ )

An affordable unit which comes with a light sensor for automatic turn-on in the dark; however, the sensor seems to have a relatively short lifetime and may break within a year or so, although the transformer has a much longer lifetime and should continue to operate.

Paradise by Steino Home 12 V, 120 W transformer for outdoor landscape lighting, astronomical timer, dusk-to-dawn, weatherproof 120 W $59.99 / 200 W $99.99

Splicing Wires

Setting up wiring outdoors often requires you to make your own connections using electrical tape and wire nuts, as many LEDs come with bare wires and no special connectors. Understanding the basics will make it much easier to choose the right set for your job.

One way to connect wires is to tape them together with electrical tape. Electrical tape is made of vinyl or other insulating plastics; vinyl is most popular because it stretches well and gives an effective and long lasting insulation.

Electricians generally use black tape for insulation purposes. In the past, yellow or white tape was common, but yellow tape in particular tends to erode under the sun because ultraviolet light weakens it. Black tape generally does not have this weakness and has thus become the industry standard for vinyl electrical tape. Therefore, you can safely use it outdoors, such as in gardens. The thickness of the tape is typically standardized to 7 mil (0.18 mm) and 10 mil (0.25 mm).

Alternatively, two or three low voltage wires can be connected together by twisting them together under a twist-on wire connector, also known as a wire nut. Wire nuts are available in a number of sizes and shapes; they are usually covered by a hard shell made from insulating plastics. Inside of the plastic nut is a metal insert with a tapered and coiled shape. When such a connector is twisted onto the stripped and intertwined ends of wires, it threads onto the twisted wires and holds them together. The connection is maintained by the direct twisted wire-to-wire contact and enhanced by the contact with the metal insert.

Wire nuts are color coded by size, so that how many wires a single nut can connect depends on its color. (drop:? Yellow connectors connect up to two 14# or three 12# wires. Orange nuts can go from two #16 to #14. Green nuts are for ground wires.) Black and blue wire nuts are typically waterproof, though they should still be encased in waterproof junction boxes for maximum safety.

The plastic nut body of the wire connector has external grooves to make it easier to handle and apply. Winglike extensions are sometimes molded into the connectors to reduce muscle fatigue when installing a large number of connectors. However, when fitting into a tight space is required, the winglike extension may cause some difficulty, and in outdoor applications, using smaller nuts can be easier to fit things properly. Smaller nuts may require wires of finer gauge; fortunately, since most LEDs require less power this is usually not an issue unless extremely long connections are required.