Low-Voltage or Solar Landscape Lighting: Which Fits a Montana Yard

What is the difference between low-voltage and solar lights?

Where the power comes from. A low-voltage system plugs into or is wired to household power through a power supply, usually called a transformer, which steps the voltage down and feeds fixtures through buried cable. The National Electrical Code covers these systems in Article 411. According to a 2004 IAEI Magazine explanation of that article, a low-voltage lighting system has a maximum of 30 volts, each circuit is limited to 25 amperes, and the systems are required to be listed, with landscape systems covered by the UL 1838 safety standard.

A solar light carries its own small power plant. A panel on the fixture charges a battery during the day, and the battery runs an LED after dark. No cable, no transformer, no trench. That is the whole appeal, and also the whole limitation: each fixture only has whatever energy its own small panel collected that day, in that exact spot.

Do solar landscape lights work in a Montana winter?

Some of the time, and least when you most want them. Three things stack up against a solar fixture here. Winter days are short and the sun is low, so the panel collects less. Snow on the panel blocks it entirely until someone brushes it off or it melts. And a path light standing a foot above grade can simply be buried, which our landscape lighting design guide covers for wired systems too.

Cold is the third problem, and it is chemistry. Battery University's guide to charging at low temperatures says extreme cold reduces a battery's charge acceptance, and that batteries charge best between 50 and 86 degrees Fahrenheit. Its table lists a charging range of 32 to 113 degrees for nickel-based NiCd and NiMH cells, with reduced rates recommended when cold, and says no charging is permitted below freezing for lithium-ion. A solar light that is dim or dark by 8 p.m. in December is behaving as expected.

Does a wired low-voltage system care about the cold?

Far less, because the power is not stored in the fixture. The transformer delivers the same power on the longest night of the year as it does in June, and it does not matter whether the fixture is in full sun or under a spruce. What winter does affect is the hardware and layout: heaving can knock fixtures out of line, and plows and shovels shear off anything at the edge of a cleared surface.

That is why a wired system has to be laid out around winter. Our landscape lighting service plans wiring clear of snow storage and plow paths and uses fixtures rated for freeze-thaw and moisture. If you already have a snow contractor, tell them where fixtures are. Our residential snow removal work starts with marking what a crew cannot see under snow.

Which is brighter and more consistent?

Low-voltage, in nearly every comparison. A wired system's output is set by the fixture and lamp you choose and stays the same all night, every night. A solar fixture's output depends on how much the battery took in, and a small panel limits how much light it can reasonably produce for a whole night. That is fine for a soft marker along a border. It is not what you want for stairs.

Brightness is not the goal in itself. The U.S. National Park Service's outdoor lighting principles point out that more light does not necessarily make a place safer, and can reduce visibility through glare. The advantage of low-voltage is control: you can set the level you want, aim it, and count on it. Consistency matters most on steps, level changes and the walk to the door, where a dark fixture is a real hazard.

How do installation and placement compare?

Solar wins on day one. Push the stake in and you are done, with no digging and no outlet needed. The catch is placement. The panel needs open sky, so a fixture under a ponderosa, on the north side of the house or behind a fence may never charge well, even if that is where you want the light. You end up placing lights where the sun is rather than where the light is needed.

A low-voltage system takes more work up front: a design, a transformer, and cable run to each fixture. IAEI explains that the total wattage of fixtures on all branches cannot exceed the rating of the power supply, which is why a system should be sized for where you intend to end up. Cable usually gets buried shallowly, so call Montana 811 first; it says you can dig two full business days after you get a ticket number, and recommends calling at least three days ahead. Any new household-voltage outlet or circuit for the transformer is a job for a licensed electrician.

What maintenance does each one need?

Solar: clean the panels, brush off snow, and replace batteries and sometimes whole fixtures as they age. Before buying, check whether replacement batteries are available at all, since not every unit is built to have them changed. Expect some attrition in this climate from frost heave, snow load on thin plastic stakes, and shovels.

Low-voltage: a yearly pass to re-aim fixtures, clear lenses and check connections, which is where most faults start. Plants grow into beams, and a fixture that was right at installation may need moving in five years. Our lighting design guide covers that in more detail. Because low-voltage systems are built to be extended and reconfigured, adding a fixture later is usually a small job if the transformer has room.

Which gives better control?

Low-voltage. A transformer can run on a timer, a photocell, or smart control, so the whole system comes on at dusk and goes off at the hour you choose. You can turn off the display lighting at 10 p.m. and keep the steps lit, or dim the system. Most solar stakes have a single dusk sensor and run until the battery is empty, whether anyone is outside or not.

That matters beyond convenience. The National Park Service recommends lighting only when needed, using timers, motion detectors and dimmers. Inside Missoula, the City's outdoor lighting ordinance requires full cutoff optics on new residential fixtures and limits light spilling onto neighboring property, and many stake lights with clear globes do not meet that description. Our guide to dark-sky friendly landscape lighting explains what that means for your choices, whichever power source you use.

What drives the cost of each?

We do not publish prices, because they depend on the property, but the factors are straightforward. Solar has a low cost per fixture and almost no installation cost, but a shorter life and repeated replacements. Low-voltage costs more up front because of design, transformer, cable, higher-grade fixtures and labor, and then costs little to run, particularly with LEDs.

For a wired system, the big variables are the number of fixtures, the distance from power, whether cable has to cross a driveway or patio, and whether the work is happening while the landscape is already open. Lighting installed alongside a new patio or walkway is far less disruptive than trenching through a finished yard, so it is worth planning conduit and cable early, even if you add fixtures later.

So which should I choose?

Choose low-voltage for anything you depend on or will look at every night: steps, walkways, the front entry, uplighting on a mature tree, stonework, and patio lighting. Choose solar for low-stakes accents in full sun, temporary lighting while you plan, or a marker far from any power source, such as a gate post or the far end of a long drive, where you accept that it may be dim or dark in midwinter.

Many properties end up with both, and that is fine. Start with one small question: what happens if this light is out in January? If the answer is that someone could trip, wire it. Our own lighting work is low-voltage design and installation, as part of our landscaping design work in Missoula and the Bitterroot. This guide is part of our Montana Landscaping, Lawn & Irrigation Guide. Call (406) 215-7319 or request a free estimate.

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