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Celebrating a Decade of Working with the City of Tempe, AZ

BEAVERTON, OR – Urban Solar is pleased to announce the ten-year anniversary of our partnership with the City of Tempe, AZ.

The City of Tempe Transportation Division operates bus, light rail, streetcar and paratransit service. A leader in providing transit stop amenities for passengers, Tempe was one of the earliest mass adopters of solar security lighting systems for bus shelters.

Although the Phoenix area has some of the best solar conditions in the United States, it is also one of the most challenging locations to deploy solar lighting due to its extreme climate. In Tempe, average high temperatures exceed 100 degrees Fahrenheit from June through September.

High temperatures can wreak havoc on battery life. As Arizona motorists know, lead acid car batteries are unlikely to survive past the two-year mark in such extreme temperatures. The same is true for standard lead acid batteries in a solar lighting system.

Having deployed several hundred solar lighting systems in the City of Tempe over the past decade, Urban Solar knows exactly what’s required to extend battery replacement intervals in extreme climates. Some of the batteries deployed by Urban Solar in 2014 are still going strong. Eben Lindsey, manager at Urban Solar, elaborates:

“In 2014, Urban Solar donated the solar lighting system for an art shelter commemorating Mary O’Connor, who enjoyed a successful career in transportation at the City of Tempe between 1990 and 2004,” Eben says. “We recently visited Tempe to assist our client with routine checkups and upgrades for older systems. While there, our team performed troubleshooting on the solar lighting system of the Mary O’Conner shelter, which had recently gone dark.”

He continues, “We expected that the system would need new batteries. However, the issue was actually caused by an errant weedwhacker, which had cut the exposed luminaire cable. The system still had its original batteries from ten years ago. Once we replaced the wire, the lights powered up, bright as ever,” Eben concludes.

The secret to great battery life in extreme environments? Firstly, it is important that systems are properly sized to minimize depth of discharge, which maximizes battery life. Next, rather than using industry-standard sealed lead acid (SLA) batteries, all systems deployed in Tempe utilize Thin Plate Pure Lead (TPPL) batteries for their temperature-resistant qualities. Finally, the City of Tempe takes full advantage of Urban Solar’s free site inspection services to ensure all systems are installed in solar-friendly locations; good solar exposure is key to long-term system health.