solar | Crossroads

The need for this research stems from documented safety benefits associated with roadway lighting and the growing challenges in maintaining traditional, wired lighting systems. While rural locations often face high costs for delivering grid power to remote intersections, recent increases in wire theft has affected communities across Minnesota. These issues highlight the importance of exploring alternative, resilient lighting solutions that can improve safety without relying heavily on conventional electrical infrastructure.

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The research process will assess the feasibility of solar‑powered LED roadway luminaires through a combination of laboratory testing, field evaluation, and cost‑benefit analysis. Key activities include analyzing battery performance under cold‑weather conditions, studying how lower illumination levels affect safety and energy use, and examining the practical integration of solar panels and batteries into existing streetlight design. A field implementation at selected sites, including potentially rural intersections or trail locations, will help validate performance and identify operational considerations such as durability, code compliance, and vandalism resistance.

The expected benefits of this work include reduced lifecycle costs, lower environmental impacts, and decreased operational and maintenance demands. Solar‑powered streetlights eliminate the need for grid‑based electricity, reduce wiring infrastructure vulnerable to theft, and offer long‑term savings over a planned service life. Environmental gains are anticipated through reduced energy consumption and lower CO2 emissions, while improved lighting reliability and appropriate illumination levels are expected to support nighttime safety and reduce crash risks statewide.

“This project will provide unbiased, objective research using equipment, methods, and people that would otherwise be unavailable to local government,” said Nick Peterson, city engineer for Saint Paul Public Works. “As a result, Minnesota cities and counties will learn effective strategies for implementing solar-powered street lighting in our cold climate.”

The Objectives:

Test energy storage capacity of Lithium-ion battery under different temperatures. The battery energy storage capacity is a critical component in the feasibility of solar powered LED street lighting in cold northern climates.
Explore the implications of running the streetlights at a lower brightness on power conservation and traffic safety. The balance between the energy demand for street lighting and the traffic safety is critical to an optimized solar powered LED streetlight that has a minimal solar panel and battery size and less effect on the existing streetlight infrastructure design.
Conduct a comprehensive cost-benefit analysis considering material, labor, and maintenance costs for the installation and use of the solar-powered LED luminaire system, along with the benefits, such as the saved utility costs, the avoided costs of nighttime crashes, and the associated environmental benefits, such as the associated reduction of CO2 emissions.
Provide MnDOT with guidelines and specifications on solar-powered LED streetlight implementation details.

Project Details: