If your landscape lighting still runs on halogen lamps, converting to LED can cut its energy use by roughly three quarters and end the cycle of replacing burned-out bulbs. But a good conversion is not always as simple as swapping lamps. The transformer, the wiring, the fixtures themselves and the color of the light all deserve a look before you buy anything.
The energy math
A typical halogen landscape lamp draws 20 to 50 watts. An LED replacement producing similar useful light often draws 4 to 7 watts, and integrated LED fixtures are commonly in the 2 to 12 watt range. A 20-watt halogen to 4 or 5-watt LED is a very common swap.
Here is what that means for a 25-fixture system running 6 hours a night, every night, at $0.15 per kWh:
| Halogen (20 W) | LED (5 W) | |
|---|---|---|
| System load | 500 W | 125 W |
| Energy per year | about 1,095 kWh | about 274 kWh |
| Cost per year | about $164 | about $41 |
That is roughly $123 a year in electricity alone, before counting the lamps you no longer buy or the time spent replacing them. With 35 or 50-watt halogens, the savings grow quickly. Plug in your own fixture count, wattages and rate below.
The less obvious benefits often matter more than the electric bill. Halogen lamps typically last a few thousand hours, which on a nightly schedule can mean replacing some of them every year or two, while quality LEDs are commonly rated for tens of thousands of hours. Halogen also runs hot enough to scorch nearby foliage and bake fixture gaskets, and a hot lamp inside a sealed housing pulls in humid air as it cools each night. Cooler-running LEDs reduce that cycle, which helps fixtures last in Gulf Coast humidity.
In deregulated parts of the Houston area, use the effective rate from your bill or your plan's Electricity Facts Label rather than a headline energy charge. Our article on how much electricity landscape lighting uses explains why.
Retrofit lamps vs integrated LED fixtures
There are two ways to convert, and they suit different situations.
Retrofit LED lamps
Replacement lamps that fit existing sockets: MR16 (GU5.3 bi-pin) for most spot and flood fixtures, and T3 or similar bi-pin (often G4) for many path lights. Low upfront cost and quick to install, if the fixtures are in good shape.
Integrated LED fixtures
The LED and driver are built into the fixture and sealed. Better heat management and moisture sealing, more consistent output, and no lamp to change. Higher upfront cost, and the whole fixture is the replaceable part.
Retrofits make sense when the existing fixtures are solid brass or copper, sealed well and placed well. If the fixtures are aluminum or plastic and already corroded, retrofitting is usually money spent on a failing housing.
Check the transformer first
Halogen systems were built around the transformer's behavior with a purely resistive load. LEDs change that.
- Magnetic transformers (the heavy, copper-wound type most professional systems use) generally work well with LED loads. They are the most forgiving option.
- Electronic transformers, common in some lower-cost and indoor-style systems, can have a minimum load requirement. Drop a 300-watt halogen load to 60 watts of LED and the transformer may fall below that minimum, causing flicker, buzzing or lights that cut in and out.
- Tap settings. Halogen runs were often set on 14 or 15 V taps to overcome voltage drop on heavy loads. With a much lighter LED load, drop falls sharply and fixtures near the transformer may now see more voltage than they are rated for. Check the LED spec and measure.
One benefit: a transformer that was overloaded with halogen is usually comfortably within its capacity after conversion. If you are rethinking the system anyway, read how to size a landscape lighting transformer.
Matching color and brightness
Halogen light is naturally warm, around 2700K to 3000K, with excellent color rendering. Cheap LED lamps can look cold, bluish or oddly flat by comparison. To keep the look you liked:
- Choose 2700K or 3000K to match the warmth of halogen. Our warm white vs cool white guide and color temperature guide explain the difference.
- Look for a high color rendering index (CRI), ideally 90 or above, so brick, stone and foliage look natural.
- Do not mix color temperatures or brands at random across the property. Two "3000K" lamps from different makers can still look noticeably different side by side.
Lumens, not watts
Watts measure power, not light. Compare lumen output and beam angle. A 20-watt halogen MR16 produces a few hundred lumens depending on the lamp, and many LED MR16s in the 4 to 7 watt range land in a similar range. Beam angle matters as much as lumens: a narrow 15 to 25 degree spot reaches up a tall loblolly pine, while a 36 to 60 degree flood suits a wide wall or a crape myrtle canopy. Match the beam of the lamp you are replacing unless you are deliberately changing the effect.
Inspect the fixtures and wiring
A conversion is the right moment to check the parts that halogen heat has been punishing for years.
- Open each fixture. Look for corroded sockets, cracked lenses, brittle gaskets and water inside the housing. Halogen heat cooks gaskets, and Gulf Coast humidity does the rest.
- Check the sockets. Green or white corrosion on bi-pin sockets causes intermittent contact. Corroded sockets should be replaced, not cleaned and hoped for.
- Inspect connections. Old pierce-style connectors are a common failure point. Proper waterproof splices make the system far more reliable.
- Look at the cable. Exposed, nicked or shallow wire in beds and along edging is common on older installations.
- Measure voltage. After conversion, check voltage at several fixtures, especially those closest to the transformer.
Re-aim after converting
LED lamps and fixtures do not always throw light exactly the way the old halogen did. Beam patterns are often tighter or more defined, and the hot spot can land in a different place. Once the new lamps are in, look at the property after dark and re-aim each fixture. This is also a good time to correct fixtures that have been knocked off target by mowers or swallowed by shrubs that have grown since installation.
When to redesign instead of swapping
Sometimes the honest answer is that the old layout is the real problem. A redesign is worth considering when:
- Most fixtures are corroded, cheap or failing
- The original design floods the house with glare rather than revealing its architecture
- Trees have matured and the lighting no longer fits them
- You have added a pool, patio or outdoor kitchen
- Everything runs on one zone with no useful control
A conversion done as part of a redesign lets you add zoning, dimming and smart controls at the same time. For simpler cases, Spring Landscape Lighting's repair and upgrade service can handle the swap and fix what it uncovers along the way.
Frequently asked questions
How much can I save by converting halogen landscape lights to LED?
Most conversions cut lighting energy by around 75 percent. A 25-fixture system going from 20-watt halogen to 5-watt LED, running six hours a night, saves roughly $120 a year at $0.15 per kWh, plus the cost of replacement lamps.
Can I just put LED bulbs in my existing halogen fixtures?
Often, yes, using MR16 or bi-pin LED retrofit lamps. It works best when the fixtures are solid, well sealed and free of socket corrosion. Corroded or cheap fixtures are usually better replaced.
Will LED bulbs work with my old landscape transformer?
Magnetic transformers generally work well with LEDs. Some electronic transformers have a minimum load and may flicker or buzz with a much lighter LED load. Also check that tap settings do not overvolt the LEDs.
What color temperature matches halogen?
Halogen is roughly 2700K to 3000K. Choosing LED lamps in that range, with a high CRI, keeps the warm look most homeowners prefer.
Are integrated LED fixtures better than retrofit lamps?
Integrated fixtures are usually better sealed and manage heat better, so they tend to be more reliable outdoors. Retrofit lamps cost less upfront and make sense when your existing fixtures are in good condition.
Spring Landscape Lighting
Landscape lighting designers serving Spring, Klein, The Woodlands and North Houston. Questions about your property? Get in touch.
