Appalachian Lighting Systems (ALSI) has introduced the ALLED SL4 LED-based street light designed to replace 70-400W HID roadway fixtures, and has integrated the ALLink control system into the luminaires.ALLED-Lighting-Fixtures-SL4

The new ALSI street lights offer Type III and V beam patterns and the company says the products can save 75% in energy relative to legacy lighting sources – in part based on the integrated network capability and adaptive controls for dimming. ALSI also announced that its sister SSL Energy Solutions business can assist municipalities in financing SSL projects, providing savings relative to current operational costs immediately.



The SL4 design features a robust thermal management scheme that ALSI says will deliver extended product life. Robert McAnally, vice president of operations at ALSI, said, “Thermal management has always been a cornerstone of our engineering principles.” McNally said that at 65°C ambient temperature, the luminaire will deliver a TM-21 projected L70 life of greater than 150,000 hours.

The design is also enhanced for robustness to surges including lighting strikes. McNally said, “Power supplies are the weak link in the industry right now.” He said surge protectors are critical for luminaire reliability. The SL4 design is rated to withstand as many as 10 power surges of up to 10 kVA.

Wireless networking

The network capability is designed both to allow for programmed dimming and off/on cycles and to monitor energy usage and the health of the luminaire. For example, the control system can report anytime a power surge occurs. And the controller can monitor and report power consumption for utility billing purposes.

The wireless network in the luminaires is based on the IEEE 802.15.4 wireless standard for mesh networks in the 2.4-GHz band that also underlies the Zigbee industry standard. McNally said that ALSI added self-healing capabilities and security features based on AES-128 data encryption. A gateway with a cellular General Packet Radio Service (GPRS) links local wireless street-light networks to a central control center.

McNally claims that the SL4 is the first networked street light to integrate the communications system on the DC-side of the luminaire power supply. Many other designs place the controller in the NEMA socket where a photocell is typically connected on the AC side of a luminaire. McNally says that the ALSI network implementation adds to the system reliability protecting the electronics inside the fixture.

Control of the system is handled via a web-based user interface with multiple levels of password protection. For example, a municipality could provide emergency service organizations with a level of access that would allow the service team to flash lights to guide workers to an emergency site.

Reducing upfront costs

ASLI is also stressing the financial side of the story that’s enabled by the company’s investment in the SSL Energy Solutions sister business. The services company can help arrange financing for utilities that struggle to pay high upfront SSL costs. And SSL Energy Solutions will also handle street-light maintenance and operations for municipalities that desire such services along with providing extended-warranty services that can stretch 10 to 15 years.

ALSI CEO David McNally said that Energy Solutions allows municipalities to deploy an SSL project with no out-of-pocket costs. Moreover, he said that the municipality’s monthly cost will be less than what it currently pays in street-light operations costs – including energy and maintenance.

We recently covered an LED street-light deployment, in Welland, Ontario, and that was the first deployment of SL4 luminaires and the first business deal for SSL Energy Solutions.

“We have evaluated LED street lights for five years and determined exactly what we would need from an LED solution to be able to make a 100 percent conversion cost justified. Only one fixture and company met our requirements,” noted David Ferguson, manager, traffic, parking, and bylaw operations in Welland. “We are excited to be moving ahead with the ALLED SL4 and the Energy Solutions program that makes it worry-free for a city like Welland, with lower than average utility rates, to immediately begin realizing significant energy cost and maintenance savings.”