Understanding the differences between AC vs DC solar power systems

for Traffic Beacons and Radar Signs

Understanding the Differences between Solar and AC Power Technology

for Traffic Beacons and Radar Signs

At Carmanah, we have used our 20-plus years of experience to perfect our flashing beacons, which are available in both solar and AC versions. Solar-powered traffic beacons have fast become the preferred choice for crosswalks, school zones, and warning signs, but there are times when AC-powered systems make sense.


When would I choose AC vs DC solar power—or vice versa?

Solar and AC are both viable power supplies for flashing beacons, but sometimes, one may be more practical, cost-effective, or efficient in a given location. Anything from shading to intensity requirements to beacon usage to distance from the power grid will affect which solution is best for a given project. Here are a few reasons you might choose one or the other.

Top 3 reasons to choose solar power systems

Looking for easy and low-cost installation:

When installation must be done quickly and affordably, solar is a good choice because, unlike AC, it requires no trenching for power, no metering, and can be installed by one or two people without extensive equipment. Solar is safe, simple, and reliable.

Distance to existing electrical infrastructure:

Solar is the better choice if there is no existing electrical infrastructure at the site, especially if trenching is required, which would make the cost to connect the beacon to the AC grid more expensive than the cost of the solar-powered version. As well, installing a solar solution does not inhibit vehicular traffic since the road is unmodified, and it does not damage the landscape.

Sustainability initiatives are in place:

When a municipality or project requires that certain sustainability requirements are met, solar-powered beacons are an easy-to-implement way to attain those goals. In addition, the Federal Highway Administration (FHWA) encourages solar-powered beacons, where possible.

Top 3 reasons to choose AC power systems

AC power is readily available:

Choose AC if a metered grid connection is right on the pole, often the case if the beacon is being added at an existing pole with overhead lights or other traffic equipment.

Location is heavily shaded:

AC will be more reliable if there wouldn’t be enough sunlight reaching the solar panel to keep the battery charged during the worst winter weather. The best way to determine if shading is a problem is for Carmanah to conduct a free assessment and provide you with our site-specific Solar Power Report™ (SPR).

Location, application, or conditions dictate AC requirement:

A combination of factors can reduce the cost effectiveness of solar. A crosswalk with heavy foot traffic in combination with heavy shading may make a reliable solar-powered solution too large for the existing pole or not cost effective; likewise, if certain light levels must be met for a school zone location with long hours of operation, it might make solar less cost-effective than AC.

How solar power works for traffic products

How does solar power work in a traffic beacon? It’s all about energy in and energy out. Hover over the diagram below to see how each step works.

What’s an Solar Power Report (SPR)?

No matter where you install your digital advisory speed sign or crosswalk beacon, we can run a comprehensive site assessment to confirm the best solar-powered solution for your project. We run a field-proven software simulation to create an Solar Power Report™ to show you how we did it. Best of all? It’s free, and we can have it ready in under an hour.

If you want to learn more, read our article about energy balance or request an SPR from our team to help you get started.

We put solar to work—let’s get started

Every project is different. Contact us today and we’ll walk through your project specs together to find the best solution—whether solar or AC—for your location and application.