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Listed below are examples of case studies including best practices and/or innovative tools/approaches. This section will grow as entries are submitted or links to other sites with useful examples are provided. If you believe your agency has utilized a best practice/approach that others could learn from, please submit a short description to AASHTO (including any pertinent links) on the Share Info with AASHTO form. Please note that currently submissions are only being accepted from governmental entities.

Arizona

Solar Powered Emergency Lights Help DOT Fleet Save Fuel in Arizona

When crews are working at the side of the road, the emergency flashing lights atop their trucks are crucial to the workers’ safety and to the protection of passing motorists. But DOT trucks must keep their engines idling to maintain power for the safety lights, without which the vehicle’s battery would quickly be drained.

According to research published by the Transportation Research Board, overnight and workday idling of commercial trucks consumes well over 2 billion gallons of fuel (mostly diesel) yearly in the United States. A study by the Arizona Department of Transportation (ADOT) showed that its trucks typically idle 60 percent of the time they are in use, primarily to provide power for emergency lights.

To save fuel and cut the amount of air pollutants emitted by maintenance vehicles, ADOT is pilot-testing a solar powered version of its traditional emergency lighting system for pickup trucks that takes advantage of Arizona’s plentiful sunshine. The pilot tests will verify the durability and performance of the lighting system under different climate conditions around the state. In 2011, the first group of ADOT vehicles was equipped with the first generation of solar light bars. In 2012, second generation light bars were installed on additional vehicles. In both versions of the lighting systems, the sun’s energy is stored in lithium-ion battery packs. As a side benefit, the new system also takes less time to install versus the traditional hard-wired emergency lighting arrangements due to its wireless operation.

A view of emergency vehicle lighting and solar panel (inset). Photo: Arizona DOT

With independently powered solar lights, crews can pull off the highway and run the emergency lights with the engine turned off. By doing so, emissions are reduced while drivers still are safely alerted to the maintenance workers along the highway.

Idle Time Cut Significantly

Results from the ADOT pilot indicate that the solar equipment has significantly cut the idle time of its vehicles. It is expected that the use of solar lights on a single light duty pickup truck could save hundreds of gallons of diesel fuel a year. ADOT staff estimates that the new lighting should pay for itself in the first 15-19 months of operation, depending upon the actual vehicle use and fuel costs.

To date, ADOT has installed programmable solar powered light bars on approximately 100 trucks out of a fleet of 4,300 vehicles, according to ADOT spokesman Tim Tait. The department has plans to incorporate improvements such as enhanced battery pack performance designed with a higher heat tolerance, improved wireless controllers with more power-level indicators, and additional lighting modules.

A view of emergency vehicle lighting and solar panel (inset). Photo: Arizona DOT

ADOT continues to test and evaluate these lighting systems, Tait said.

“Having emergency lights that can operate without an engine running saves all of us money on vehicle maintenance. It reduces wasted fuel and helps the environment while still meeting the safety needs of ADOT workers," said John Nichols, ADOT Director of Administrative Services

More information is available from ADOT by contacting Tim Tait at (602) 712-7070, TTait@azdot.gov.

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California

Caltrans Works to Advance 'Smart Mobility' Approach

Since 2010, the California Department of Transportation has been working to implement a new vision for integrating transportation and land use decisions that promises to combine a range of familiar solutions taking hold across the nation: smart growth, livability, context sensitive design, transit-oriented development, complete streets, and sustainability.

Caltrans’ “Smart Mobility 2010” framework was developed to ensure that the state’s transportation investments achieve balanced outcomes for mobility, environmental protection, social equity, and economic growth – all backed by specific performance measures.

Caltrans describes the concept as follows: “Smart Mobility moves people and freight while enhancing California’s economic, environmental, and human resources by emphasizing: convenient and safe multi-modal travel, speed suitability, accessibility, management of the circulation network, and efficient use of land.”

Developed using a smart growth program grant from the Environmental Protection Agency, the framework establishes six Smart Mobility principles to be applied based on specified place-types, each with its own set of performance measures.

The six principles are:

  • location efficiency,
  • reliable mobility,
  • health and safety,
  • environmental stewardship,
  • social equity, and
  • robust economy.

Under the Smart Mobility approach, transportation planning and design would be conducted based on seven newly established place-types: urban centers, close-in compact communities, compact communities, suburban areas, rural and agricultural lands, protected lands, and special use areas.

For each place type, performance measures would be targeted to align with the principles. Types of performance measures include the following:

  • support for sustainable growth;
  • transit mode share;
  • accessibility and connectivity;
  • multi-modal travel mobility, reliability, service quality, safety;
  • design and speed suitability;
  • pedestrian and bicycle mode share;
  • climate and energy conservation;
  • emissions reduction;
  • equitable distribution of impacts;
  • equitable distribution of access and mobility;
  • congestion effects on productivity;
  • efficient use of system resources;
  • network performance optimization; and
  • return on investment.
Increasing pedestrian mode share in San Francisco. Photo: Caltrans

Interregional Blueprint Process

The plan also calls for a “transformed state transportation planning process” developed through a multimodal “Interregional Blueprint” process, incorporating transportation and land use planning efforts underway by regional and metropolitan planning organizations in the state.

California is subject to some of the nation’s most ambitious environmental and sustainability goals, including the landmark Global Warming Solutions Act (AB 32), under which the state must reduce greenhouse gas emissions to 1990 levels by 2020.

In addition, Senate Bill 375, enacted in 2008, requires regional targets for reducing greenhouse gas emissions from passenger vehicles. SB 375 – which has been touted as a possible national model for transportation planning – establishes a process and incentives for the creation of integrated regional land use, housing and transportation plans called “sustainable communities strategies.” Building on these regional efforts, SB 391 passed in October of 2009, requires that the California Transportation Plan prepared by Caltrans identify the statewide multimodal transportation system that will achieve the state’s climate change goals.

The California Interregional Blueprint, a statewide land use-transportation plan will integrate the state’s various modal plans and incorporate individual blueprints developed by regions across the state. Caltrans currently administers the California Regional Blueprint Planning Program for regional transportation planning agencies to conduct comprehensive scenario planning, bringing together a range of stakeholders to develop preferred long-range growth scenarios.

The Interregional Blueprint will incorporate the Smart Mobility principles and improve modeling and data gathering, serving as the foundation for the next update of the California Transportation Plan. The Interregional Blueprint planning process is underway.

Next Steps

A number of short-term actions will be undertaken between 2012 and 2014 to develop and test approaches to implement the Smart Mobility principles and performance measures. These include applying the framework in separate planning efforts in the northern and southern portions of the state. The agency plans to document these efforts and develop a “how-to” guide for implementation.

The vision for using the framework is described by Caltrans as follows:

  • find your place type;
  • forecast transportation needs;
  • apply Smart Mobility principles;
  • assess Smart Mobility Performance;
  • prioritize transportation investments;
  • achieve Smart Mobility.

Additional Efforts

Other efforts include a Caltrans-funded study, Improved Data and Tools for Integrated Land Use-Transportation Planning in California, which was completed in October 2012. Over a three-year period, the project team collected and analyzed data on land use-travel relationships at more than 200,000 locations in most of California. The project provided a final report as well as analytical tools for use in “sketch”-planning tools, which local and regional agencies use to assist in developing scenarios, and travel demand forecasting models, which are commonly used to analyze resulting scenarios. These products will be helpful to regional agencies in their Blueprint and sustainable community strategies and regional transportation planning, and to local governments for their planning efforts. Another significant Caltrans effort has been implementation of its complete streets directive.

Caltrans also has completed a survey, “Smart Mobility: A Survey of Current Practice and Related Research,” that looks at federal, state and regional activities to assess the current state of the practice of sustainability-oriented planning and performance measurement

For additional information on the framework, link to the Smart Mobility page on the Caltrans website or contact Chris Ratekin, senior transportation planner with Caltrans, at Chris_Ratekin@dot.ca.gov. Information on the planning process may be accessed at in the interregional blueprint web page.

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Massachusetts

MassDOT Public-Private Partnership Generates Solar Energy on Highway Rights of Way

Generating 6 megawatts (MW) of electricity per year from solar farms is not a typical goal for a state transportation agency. But for Massachusetts DOT (MassDOT), setting that goal is part of a 20-year public-private partnership it has embarked upon with a renewable energy company located in the eastern part of the state.

Under the contract, the private sector partner has agreed to finance, develop, design, construct, commission, operate, maintain, and eventually decommission solar facilities at ten pre-approved sites it leases across the state. The rows of ground-mounted solar panels are located on small parcels of state-owned land along highway embankments, exit ramps, and service plazas.

Phase 1A of the MassDOT Highway Right of Way Solar Photovoltaic Energy Program was completed in October 2015 and included five locations. Phase 1B, comprising five additional locations, is awaiting start of construction. And Phase2A, as envisioned, will include three additional sites.

“We are very pleased to be spearheading an initiative that is bringing both economic and environmental benefits,” says Hongyan Oliver, Project Manager of the solar program.

Solar arrays, such as this facility along I-90, are being developed on MassDOT’s highway rights of way. Photo: Massachusetts DOT

“The state expects to generate at least $15 million in savings over the contract period. These savings include about $2 million in rent from the leases on state properties, money that goes into the state’s transportation fund. What’s more, the arrangement entailed zero upfront capital cost for us,” according to Oliver.

Another advantage of forming a public-private partnership is the generous incentives available to the private sector partner. In this case, besides receiving a federal income tax reduction, its partner also is tapping into the state’s Solar Renewable Credits (SREC) system. For its part, MassDOT obtains all net metering credits and associated energy savings. The state’s net metering policy allows a customer to sell power generated by distributed generation back to the grid at a certain price (the meter spins backwards).

“We are purchasing 100 percent of the electricity these solar farms are generating,” explains Oliver. “And because our partner is benefitting from the solar incentives, the purchase rates we have been able to negotiate are significantly lower than current utility rates. At this point, the solar power from the ten planned sites can meet approximately six percent of our needs; we expect that figure to rise as more solar farms from our partnership enter the grid.”

The solar program also brings strong environmental benefits. The power being generated will produce zero greenhouse gas emissions, says Oliver, thereby supporting Massachusetts’ commitment to a green and clean economy. It also supports MassDOT’s GreenDOT sustainability initiative.

“Once we fully reach our goal of generating 6 megawatts (MW) of electricity per year, we anticipate a CO2 emissions reduction of approximately 6.8 million pounds annually due to replacing fossil fuel electricity in the grid with solar power,” Oliver explains. “That is the equivalent of annual greenhouse gas emissions from 630 passenger vehicles.”

Trending

MassDOT has joined a small but growing number of state DOTs that are beginning to utilize highway rights-of-way (ROW) as locations for siting renewable energy production facilities. Oregon led the way in 2008, becoming the first agency in the United States to install a solar panel array along a highway ROW (see related case study). Over the next several years, Ohio and Colorado followed suit. In addition, at least seven state DOTS have constructed solar array or wind turbine installations at rest areas or carports that abridge highways, according to a recent FHWA publication.

Original Impetus, Careful Site Selection

The agency began its foray into the solar energy field in 2011 by releasing a parcel of state land adjacent to a highway to the adjoining town. The town had received an American Recovery and Reinvestment Act grant to produce solar power for its water treatment plant.

“Actually, we received indirect benefits from the project in that the public began to become accustomed to the concept of solar panels being installed next to a highway,” Oliver explains.

During that same year, her agency was beginning to have discussions about developing what now is the MassDOT solar program.

“One of the first things we did was contact our counterparts in Oregon,” Oliver explains. “Although the business model we eventually selected was different, many other components were the same. ”

The agency began with a small pilot project in the western part of the state designed to supply one-third of the energy needs of a nearby District Highway Administration building. Then it was time to move into the next phase, its multi-facility program.

“Realizing that site selection was one of the most critical elements, we hired a consultant to do the evaluation,” says Oliver.

Criteria for selection included parcel size and orientation, any existing environmental concerns, distance from the grid, easy access during construction, no interference with highway operation, and no conflict with future transportation use. Another consideration was whether a site was adjacent to a federally-funded highway, which would mean obtaining FHWA approval. Finally, if either environmental concerns or a solar zoning by-law was present, town approval would be needed.

Once sites were selected, a Request for Response (RFR) was sent out and the current partner company was selected after a three-stage competitive process. Prior to the issuance of the RFR, the Department updated its utility accommodation policy in coordination with the FHWA Mass division. Its policy now includes guidelines for renewable energy technologies. It also outlines safety criteria and design standards, the project development process, compensation requirements, and relevant license and lease agreements.

Less conspicuous than the rows and rows of solar panels, the inverter, transformer and data acquisition system are the heart and the brain of a solar farm. (Photo: Massachusetts DOT)

Multiple Installations, Multiple Advantages

“Developing multiple sites across the state under the same program umbrella makes us somewhat unique,” says Oliver. “From our perspective, this approach has a number of advantages.”

First, she explains, it requires only one procurement document, and the process is carried out through a single open bid. Second, with multiple sites in the same project, the owner and operator of the solar farms may be able to purchase equipment and subcontractors’ services in bulk at a discount, and construction mobilization can occur at multiple sites simultaneously.

“In addition,” according to Oliver, “we have been able to learn through experience as we move through the program and integrate more strategic approaches along the way.

Replicability

Other states may be well positioned to create similar programs, she said. Those that decide to pursue such a program should be aware of any site conditions or regulatory constraints that can affect generation capacity as well as available incentives.

“In our case, for instance, construction for the five sites in Phase 1B originally was slated to begin in spring 2015. However, that start date has been put on hold due to the situation of excess-demand for net metering incentives in Massachusetts.”

Oliver also advises that other states “work very closely with other divisions and sections to incorporate all concerns and requirements during site selection and development.”

Fortunately, she continues, her Planning Division uses a 25-year projection window, an extremely compatible timeframe in this case. She and her team members maintained constant communication throughout the process, especially during site selection.

Oliver concludes, “So far, the decision to use some of our highway right-of-way land to produce solar energy has proven to be extremely sound. And looking ahead, we anticipate only more of the same. ”

For more information, contact MassDOT Project Manager Dr. Hongyan (Lily) Oliver at Hongyan.Oliver@state.ma/us or link to http://www.massdot.state.ma.us/energyinitiative/Solar.aspx.

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Oregon

'Solar Highway' Offers Model Approach for Renewable Energy

An array of hundreds of solar panels stretching 540 feet along an Oregon highway is helping to power a nearby interchange with clean, renewable energy through a unique public-private partnership that could serve as a model for the nation.

Oregon’s “Solar Highway Project” sits at the interchange of Interstates 5 and 205 in Tualatin, Ore., at the south end of the Portland metropolitan area. The project is the nation’s first roadside solar photovoltaic demonstration project.

According to the Oregon Department of Transportation, the project’s 594 solar panels produce about 122,000 kilowatt hours annually. The panels produce energy during the day which is used to light the interchange at night. ODOT buys the energy produced by the array at the same rate the agency pays for regular energy from the grid.

This clean, renewable source of energy will help the agency meet the mandate from Oregon Gov. Ted Kulongoski that state agencies obtain all of their electricity from renewable sources. By replacing energy from the grid, the solar electricity produced by the project will avoid the production of nearly 43 metric tons of carbon dioxide equivalent emissions each year.

The $1.28 million project, which has been in operation for just over one year, was developed through an innovative public-private partnership between ODOT; Portland General Electric (PGE), Oregon’s largest utility; and US Bank. Material providers included Solar World US, the nation’s largest solar panel manufacturer, and PV Powered, the nation’s largest inverter manufacturer.

Making the Most of the ‘Right-of-Way Asset.’

ODOT Project Director Allison Hamilton explained that under this unique partnership “the public gets multiple values out of its right-of-way asset.”

“Using state and federal tax credits, the renewable energy projects are developed at least possible cost, which benefits the utility rate payers – including ODOT and the State of Oregon, “ Hamilton said. At the same time, ODOT gets green energy at grid rate instead of the higher green energy rate, she added.

“The solar energy project is owned, operated and maintained by the utility, which also assumes all the risk, and is responsible for maintenance of the right of way for the term of the contract (from 25 years up to 40 years or more),” Hamilton explained. But the utility also gets to count the project towards its renewable energy portfolio requirements, she said.

“It’s a win-win-win business model,” Hamilton added.

ODOT officials and PGE officials have deemed the project a success, demonstrating that solar arrays can complement and not compromise the transportation system.

In fact, Hamilton said the project has exceeded expectations, producing more than the expected 112,000 kilowatt hours in its first year, with only one maintenance incident where a panel was cracked and had to be replaced.

As a result, Oregon DOT and its partners – utility providers and private businesses – are poised to expand production of solar energy at the demonstration site and as well as other locations in the state.

Third Party Financing Model

According to ODOT, these public-private partnerships are expected to follow the same type of third-party financing model developed for the demonstration project.

“The utilities would contract with solar developers to design, build and install the arrays, which they – the utilities or limited liability companies involving the utilities – would own, operate and maintain, and which could count towards meeting statutory requirements to develop renewable energy resources. The utilities would also be responsible for maintenance and successful operation of the arrays, including any damage due to vandalism or crashes,” according to a summary on the demonstration project website.

ODOT would have a 25-year agreement to purchase all electricity generated by the solar projects, with options to renew for up to three five-year extensions.

DOTs Urged to Work with Utilities

Hamilton said many other states have expressed interest in following Oregon’s lead, but she stressed that each state will have unique circumstances. “Because each state has its own utility regulations, I would recommend project proponents work with or through their utility to learn the most efficient and cost effective way to size, permit and connect a project, and also to determine the most advantageous financing and ownership model,” she said.

“We learned that the larger the installation, the better, as you are able to spread your fixed costs out over more kilowatts, bringing down the cost per installed kilowatt” compared to the cost of existing grid energy.

Hamilton urged transportation agencies that are interested in developing a solar highway project to take advantage of the expertise of the utility, whose core business is energy generation.

“Oregon’s state transportation system has nearly 19,000 lane miles of right-of-way and there are more than 8 million lane miles of right-of-way across the nation,” according to an ODOT project summary. “Solar arrays on less than 1 percent of Oregon’s right-of-way could supply the nearly 50 million kilowatt hours needed annually by the state transportation system,” the agency said.

The project has been recognized with numerous honors, including the Federal Highway Administration’s 2009 Environmental Excellence Awards.

A wide range of information is available on the project website, www.oregonsolarhighway.com, including a solar highway meter that tracks energy generated on-site, news releases, photos, videos, research, technical documents, and information on planning for future projects. Additional information also is available by contacting Allison Hamilton at allison.m.hamilton@odot.state.or.us.

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Tennessee

Tennessee DOT's 'Green Islands' Program: Distributing Renewable Fuels Across the State

The Tennessee Department of Transportation (TDOT) is promoting the use of renewable fuels across the state, increasing the number of fueling stations that offer renewables through its “Green Islands” program.

While E10 (a mixture of 10 percent ethanol and 90 percent gasoline) is now widely available, an increasing portion of the U.S. automobile fleet has been manufactured to be "flexfuel," and able to use E85 (a mixture of 85 percent ethanol and 15 percent gasoline). Additionally, most diesel engines are able to use B20 (a blend of 20 percent biodiesel and 80 percent petrodiesel). However, a major impediment to increasing adoption of renewable fuels such as E85 and B20 is the lack of infrastructure to distribute the fuel.

TDOT faced this issue by helping establish a "green islands biofuel corridor network" of fueling stations not more than 100 miles apart along the highways that connect the state's major cities and destinations. The goal of "green islands” is to enable travel across the state using biofuel exclusively. These alternative fuel stations provide public access to biofuels along major corridors for consumers wishing to use them and reduce their consumption of fossil fuel. While some gaps in the network remain, TDOT will continue to offer grants to fuel stations as incentives to fill the gaps.

Tennessee DOT’s Green Island program increases public access to biofuels. Source: Tennessee DOT

“Increasing the availability and use of biofuels in Tennessee will help increase energy security, reduce air pollution and benefit the state’s economy, according to Alan Jones, Manager of the Policy Office in TDOT’s Long Range Planning Division. “The Green Islands grant program encourages fuel stations to offer these fuels to the driving public,” he said.

‘Farm to Fuel Tank’ Vision

The benefits of reducing fossil fuel consumption and displacing imported petroleum with alternative fuels have been discussed for many years. However, the "green island" concept accelerated in the early 2000's when the Tennessee Farm Bureau started investigating how the state's agricultural community could assist in biofuel production. A vision of a vertically integrated biofuels industry wholly within Tennessee ("From Farm to Fuel Tank in Tennessee") began to take hold.

The Tennessee legislature was called upon to pass legislation to implement the vision. Proponents discussed obtaining seed money, such as grants, to advance the concept. The legislature determined that encouraging in-state biofuel production was in the state's economic interest, and therefore worth providing incentives. One law passed by the legislature named the TDOT to be the agency to manage a grant program for fuel stations to encourage increased availability of biofuels to motorists and vehicle fleet owners in the state. The grant program offered funding to purchase and install biofuel storage and fuel dispensing equipment across the state. TDOT stepped up, administering a program to provide public access to the fuel.

TDOT has since published several Requests for Proposals (RFP) aimed at gas stations willing to make biofuels publicly available for four years, in return for grant funding to help purchase and install the infrastructure. A subsidy was set at a maximum of $45,000 per biofuel pump. The maximum grant was capped at $90,000 for a single location, if the station proposed to sell both biofuels, E85 and B20, to the general public.

While most applicants proposed one or two pumps, several owners proposed multiple stations to achieve economies of scale. One owner proposed three locations, and received a total benefit of $270,000. Presently there are 60 E85 pumps statewide. Around half were installed by private sector operators deciding on their own to offer biofuels to their customers.

When stations meet their four-year contract obligation, many continue to sell the fuels, but some do not. Stations that have been the most successful helped market the fuel on their own. The vision of "From Farm to Fuel Tank in Tennessee" remains, although increasing the use of biofuels has lagged for numerous reasons. State grant funds remain available for stations still interested in selling alternative fuels.

Funding for the program has come from several sources. The state's first E85 pump, which came on-line in 2003, was funded by the U.S. Department of Energy. In air quality nonattainment areas, TDOT used funds from the Federal Highway Administration's Congestion Mitigation and Air Quality Improvement Program. TDOT also received significant state funding from the state’s General Assembly for the green islands program.

An important part of the program includes increasing public awareness about biofuel, its benefits, and where drivers can purchase these cleaner fuels. As part of the interstate blue logo sign program, TDOT developed and posted blue signs with a biofuel image to advertise the locations of green island stations.

Grants provide an incentive for fuel stations to install the fueling infrastructure but, in the long run, stations will not continue to sell biofuels unless their customers buy them. Sustaining market demand for biofuels will require a more vigorous advertising and public education campaign at the state and national level.

For more information on the program, contact Alan Jones, Policy Manager, Long Range Planning Division, TDOT, at Alan.Jones@tn.gov.

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Vermont

Vermont’s Solar Power Plan Aims to Help Meet Renewable Energy Goals

The Vermont Agency of Transportation (VTrans) expects to use an increasing number of properties and rights-of-way for the installation of solar power projects that could help the agency meet its renewable energy goals, reduce emissions and save money, joining seven other state departments of transportation in developing such facilities.

The Vermont Agency of Transportation Solar Plan was issued in December 2016 to help with the complex decision making involved in siting and operating solar projects.

The plan defines for the agency the costs, benefits and processes of solar photovoltaic (PV) installation in the state, with the goal of understanding and navigating toward successful solar developments. The plan is required by state law, but just as importantly it serves to communicate the agency’s goals to the public, said Gina Campoli, a retired VTrans project manager who oversaw the plan development.

The Vermont Agency of Transportation is installing solar projects to offset energy use at its properties statewide, such as this solar array at the Rutland Airport. Photo: VTrans

“The former [state transportation] secretary felt it was very important for the public to understand the various processes that we were using to develop projects, [including] why we were developing projects, why on Earth the Agency of Transportation was getting into the solar business, what were the processes we were going to use when we planned projects, just like we would for a transportation project,” Campoli said.

Vermont joins a growing number of state DOTs, including Arizona, Connecticut, Florida, Massachusetts, Minnesota, Ohio and Oregon, that are beginning to use transportation properties for siting renewable energy facilities, according to the plan. Vermont used Oregon DOT’s solar plan as a reference for their own, even commissioning the same consulting firm to prepare the plan, Campoli said. (See related case studies for Massachusetts and Oregon.)

Solar PV at VTrans

There has never been a better time for VTrans to install solar generation, according to the plan. It describes several factors driving the momentum for solar PV at VTrans. These include:

  • Saving on energy costs. Systems that VTrans has already installed in Rutland and at various maintenance garages statewide are providing significant cost savings for electricity, with the project at the Rutland State Airport expected to save the agency $400,000 over 30 years.
  • Installation costs are going down each year. Using VTrans staff for construction saves even more on up-front costs, a strategy the plan recommends for smaller projects.
  • Aligning with state policies to consume cleaner energy, mitigate climate impacts, and build resilience. In the event of an emergency loss of power, PV systems can provide continuous power to VTrans or to feed power back to the grid, creating greater resilience.

Also, the Vermont state Comprehensive Energy Plan sets an ambitious goal of having 90 percent of the state’s energy needs—both state government operations and the private sector—met by renewable sources by 2050, Campoli said. For VTrans, that means power for street lights, traffic signals, all of the equipment in the maintenance garages, computers and office lights. “There is a ton of power we consume,” Campoli said.

The state energy planning requirement has allowed VTrans to document and better understand its energy footprint, Campoli said. Knowing the amount of energy use “justifies the investment in solar,” she said.

“There is enough sun in Vermont,” Campoli said.

How to Implement

The plan discusses how VTrans—or any other state DOT—would pursue development of more solar PV projects, steps that include assembling a project team, evaluating potential project sites, evaluating financial arrangements and ownership models, performing due diligence, and final implementation.

At VTrans, a team has already screened candidate sites at VTrans-owned properties and highway rights-of-way sites. Using tools such as VTrans’ geographic information system, the mapping office found that 124 out of 375 sites demonstrated potential for solar PV. Further screening has narrowed the list to 24 sites.

After sites are identified, VTrans must conduct analysis to determine whether the site merits continued development. Such analysis includes a study of the requirements for utility interconnection, environmental impact analysis at the state and, if necessary, federal level, and engagement with stakeholders and the public.

As a public agency, VTrans would need to investigate possible public-private partnerships including a power purchase agreement—where the agency agrees to buy electricity from the project developer—and a site license or lease agreement that grants a third party the right to install the system. Also, VTrans would need a net metering agreement with the local utility to allow the agency to receive credit for its power production, something VTrans is already doing with the solar arrays installed at maintenance garages, Campoli said.

Key Considerations

VTrans will need to make some organizational adjustments to continue to pursue solar projects. The plan recommends having a dedicated PV projects manager and the necessary support from agency leadership.

Additionally, VTrans must consider the markets for renewable energy, federal and state financial incentives, and regulations and policies with regard to renewables, including Vermont’s own renewable energy standard.

If using federal-aid rights-of-way, state DOTs must comply with all federal requirements including ensuring that vehicle safety and the transportation purpose are not compromised, and performing environmental review under the National Environmental Policy Act. Campoli noted that placing solar facilities within federal right-of-way increases the complexity of the project, and therefore nearly all of the projects VTrans has installed so far have been on state land. The 24 sites that VTrans has identified as having a high potential for solar PV are mostly either VTrans maintenance garages or regional airports.

According to the plan, if the project is for a public utility, siting and permitting can be managed in accordance with state's approved utility accommodation policy (UAP) without further FHWA approval. Facility types not currently in the UAP must be referred to the FHWA division office, and projects that are strictly for private use are subject to federal right-of-way use agreement regulations.

Lessons Learned

The VTrans renewables plan is part of a state planning effort that is an interagency collaboration including the Department of Buildings and General Services and the Department of Public Service, the state’s utility regulator, Campoli said. “We’ve broken down silos on this issue,” she said.

Also, the projects that are operational are already paying dividends. “The Rutland Airport is producing way beyond our wildest expectations,” Campoli said, noting that production can exceed what is promised by PV panel manufacturers.

Additionally, more land with solar panels equals more solar power generation. However, it is important to site the solar panels in locations that consider future transportation needs, Campoli said, by making sure that the panels are not where a future storage area or parking lot will need to go. Meeting the agency’s goals for renewables will require VTrans to find additional sites, such as interchanges or cloverleaves, former quarry or gravel sites, brownfield sites, inactive or abandoned weigh stations, and park and ride areas, the plan said.

Next Steps

VTrans has set a renewable electricity goal for the agency of 25 percent. To meet that target, an additional 610 kW of capacity—that generates 715,000 kWh—is needed. This capacity is equivalent to an additional seven projects like the system installed in 2016 at Fair Haven Welcome Center or 36 additional 15 kW garage projects.

For these larger PV facilities, such as the 75 kW Fair Haven project within the federal right-of-way, the agency will need to establish partnerships. VTrans also should continue to coordinate with stakeholders such as the Vermont Energy Investment Corporation and the various regional planning commissions to determine if VTrans sites could meet mutually beneficial goals, the plan said.

For more information, link to the Vermont Agency of Transportation Solar Plan or contact Daniel Dutcher, Vermont Agency of Transportation Senior Environmental Policy Analyst at Daniel.Dutcher@vermont.gov.

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    The Vermont Agency of Transportation is installing solar projects to offset its energy use, such as this solar array at the Rutland Airport.

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