24V vs 36V Permanent Outdoor Lights: Which Voltage Is Better?

Quick answer: For most residential and professional permanent outdoor lighting projects, 24V is the strongest standard platform because it balances electrical safety, product availability, installation flexibility, certification compatibility, and system cost. A 36V system becomes attractive when longer runs or higher fixture counts make voltage drop a major design constraint.

Why system voltage matters

Permanent outdoor lighting is a distributed electrical system. Power leaves the controller, travels through cable and connectors, passes through fixtures, and must still arrive at the final light with enough voltage for stable operation. The longer the run and the higher the current, the more difficult that becomes.

The basic relationship is simple:

Current = Power ÷ Voltage

For the same 240W load, the approximate current is 20A at 12V, 10A at 24V, 6.7A at 36V, and 5A at 48V. Lower current generally means less voltage drop and less heating in the cable, connectors, and PCB traces.

Why 24V works well as a standard platform

Compared with 12V, 24V cuts the current roughly in half for the same power. That is a major improvement for roofline installations where cable runs can be long. At the same time, 24V remains a practical low-voltage architecture for residential and professional systems.

A properly designed 24V permanent outdoor lighting system can work well with RGBW fixtures, multi-output controllers, 18 AWG or 20 AWG cable, and common 6-inch, 8-inch, 9-inch, or 12-inch fixture spacing.

For G&D Smart, this makes 24V the preferred standard platform: it is flexible enough for most homes while keeping the product family, controller platform, spare parts, and installer training relatively simple.

Where 36V has an advantage

The main advantage of 36V is lower current for the same transmitted power. This becomes valuable when a project has long rooflines, high fixture counts, or difficult cable-routing conditions.

For example, a 144W load draws about 6A at 24V but only about 4A at 36V. That difference can materially reduce voltage drop over a long conductor path.

36V is therefore useful for long-run professional applications where the designer wants to reduce current and avoid excessive power injection.

But higher voltage is not automatically better

Voltage should not be selected only by asking which option can run the farthest. The installer also needs to consider the certified use environment, wire type, connector ratings, output protection, controller architecture, and the minimum acceptable voltage at the last fixture.

For outdoor low-voltage lighting systems evaluated under UL 2108, UL explains that wet-condition low-voltage power architectures commonly limit the power unit to 15Vac or 30Vdc. This is one reason 24V is especially attractive when a certified Wet Location system is required. A 36V or 48V product may still be appropriate in other outdoor applications, but its exact listing, location rating, and installation instructions must be checked rather than assumed.

24V vs 36V comparison

Recommended selection strategy

Choose 24V for most residential permanent outdoor lighting systems, especially when standardization, broad installer compatibility, and Wet Location certification strategy are important.

Choose 36V when long transmission distance and lower current are the primary engineering priorities and the application environment is compatible with the system's listing and installation instructions.

Choose 48V only as a more specialized professional or custom platform where the project justifies the added system separation.

The engineering rule that matters most

The best system is not the one with the highest voltage. It is the one that delivers stable voltage to every fixture while keeping cable current, connector loading, certification, and installation complexity under control.

Reference: UL Solutions, Landscape and Outdoor Luminaire Lighting — low-voltage lighting systems under UL 1838 and UL 2108.

G&D Smart engineering perspective

G&D Smart develops professional permanent outdoor lighting systems for installers, regional lighting brands, distributors, and OEM/ODM partners in the United States and Canada. Our platform combines RGBW roofline fixtures, matched mounting profiles, controller and power-distribution hardware, cable and connector standards, and installer-oriented software.

For G&D Smart, 24V is the primary standardized installer platform; 36V is positioned as a professional long-run option where lower current and reduced voltage drop provide a measurable installation benefit.

Related G&D Smart system components: C5204 Permanent Outdoor Lights and GC08 Control Box.

FAQ for installers and lighting brands

Is 36V always better than 24V for permanent outdoor lights?

No. 36V lowers current for the same power, but 24V is usually easier to standardize and is better aligned with low-voltage Wet Location strategies when the complete system is properly certified.

Which voltage does G&D Smart recommend as the standard installer platform?

24V is the preferred standard platform. 36V and 48V are better treated as professional or application-specific options rather than replacing 24V everywhere.

Choose a voltage for a real roofline layout

Compare the 24V system architecture with the 36V system architecture, then estimate branch load and cable distances with the permanent lighting calculator. For brands or installers defining a repeatable BOM, request a project review.

Technical content prepared by the G&D Smart Engineering Team. Final installation requirements must follow the listing, markings, instructions, local electrical requirements, and the exact components used in the project.