Tag Archives: energy

Study Underway to Harness Renewable Energy from Minnesota’s Highways

Sound barriers and snow fences along highways have the potential to provide clean energy in Minnesota.

A newly funded MnDOT study, Harnessing Solar Energy through Noise Barriers and Structural Snow Fencing, is investigating how to utilize existing noise barriers and snow fences on Minnesota highways to harvest clean, cost-effective energy.

“Snow fences and noise walls are structural barriers with a singular purpose. Snow fences are intended to limit snow from drifting onto our highways and noise walls are intended to reduce noise to a comfortable level for communities living near our highways. Finding a way to integrate solar that maintains their structural integrity could transform the use of these barriers from single purpose to multi-purpose,” says Dan Gullickson, MnDOT’s Blowing Snow Control Shared Services Program Supervisor, who is overseeing the research project.

Solar energy is energy captured from the sun and converted into thermal or electrical energy. It is a clean and abundant renewable energy source and generally requires very little maintenance after installation. Solar energy has a variety of uses, including providing electricity to power street lamps and homes, heating and cooling spaces, and heating water.

“We’ve seen some applications of solar panels on noise walls—primarily in European countries—but the addition of solar panels to snow fences is an entirely new concept,” says Gullickson.

The innovative nature of this project brings many unknowns that MnDOT hopes to answer, such as: Is it possible to engineer these structures without disrupting their functionality? What safety measures need to be taken to ensure the public and MnDOT workers stay safe if they come into contact with the panels? What are the lifecycle costs of installing and maintaining solar? How much energy could they generate and how does that connect with existing power grids?

One estimate shows that a thousand miles of solar panels could power all the street lights along Minnesota highways or 43,333 residential homes. (Assuming each solar panel is 330W and 1,000 panels could generate up to 330kW per mile.)

Harnessing solar energy on Minnesota highways: Solar energy can be used for heating, cooling, lighting, and warming water. 1,000 miles of solar panels on Minnesota highways could power: All of minnesota highway lights o 43,333 residential homes.

“We know Minnesota and North Dakota winters bring a lot of snow—which is disruptive to our travelers and farmers. We hope to create a sustainable solution that aids drivers and farmers, but also harnessing energy which would be able to offset the cost of construction and installation,” says Mijia Yang from North Dakota State University, the lead researcher.

Gullickson and a diverse team of MnDOT experts – from the field of environmental stewardship to traffic engineering – will guide the research and review findings.

The study will include surveys, lab testing or modeling of possible design options and a cost-benefit analysis—planned to be completed by of June 2021.

Currently, the research team is developing surveys to better understand public opinion on solar energy (including energy prices and solar panel infrastructure), power companies’ interest in purchasing solar energy generated through the right-of-way and legal considerations for harvesting solar energy through the rights-of-way.

 “Surveying the public and utility providers may uncover questions that we hadn’t previously anticipated. We hope to address those hurdles throughout the study,” says Gullickson. Follow along for project updates on MnDOT’s Office of Research & Innovation website.

Are energy-efficient streetlights cost-effective?

In 2010, the City of Minneapolis installed 55 energy-efficient streetlights from nine different manufacturers along 46th Street between 34th and 46th avenues. The project, part of Hennepin County’s Minnehaha-Hiawatha Community Works program, was designed to field test various models of light-emitting diode (LED) and induction lights. Over the course of two years, researchers observed, evaluated and compared the performance of various lighting products, detailing the results in a recently published report available on the MnDOT Research Services website.

In a broad sense, the results of the study would appear to confirm what has become common knowledge regarding energy-efficient technologies: while they cost  more up front, in the long run they have the potential to save money in the form of reduced energy and maintenance costs. The study also demonstrates that  energy-efficient streetlights are capable of producing adequate light output and are well-received by residents.

However, if the big question is whether energy-efficient streetlights can save local governments money, the answer  is somewhat complicated. The study found that both the levels of light ouput and the amount of time it takes to recoup costs varies significantly by product. Page 16 of the report (page 25 of the PDF) features a table comparing various products’ light output and estimated payback time. With one notable exception, the results show that products with the highest light output (i.e. the highest performers and therefore the most desirable) tend to also have the longest payback time. The amount of time it takes to generate a cost savings from energy-efficient streetlights can be as short as 2.6 years or as long as 24 years, depending on the product.

Some other interesting tidbits from the study:

  • Researchers observed operational cost savings of 50-75 percent, depending on the product.
  • Eighty percent of the savings came from reduced maintenance costs, while only 20 percent came from reduced energy costs.
  • In a survey of area residents, 76 percent responded positively to the new, energy-efficient lights.

The study demonstrated that energy-efficient streetlighting is a feasible option for local governments, with the caveat that agencies need to research lighting products thoroughly before making a choice as to which one to use. Ultimately, considering the ever-decreasing cost of LEDs, the use of energy-efficient streetlighting technologies is likely to grow.

Read more: