Turning Roadsides into Solar Farms

As you drive along America’s vast highway network, have you ever considered the sheer amount of unused land stretching alongside our roads? The United States maintains over 4 million miles of roadways, with approximately 223,000 miles dedicated to interstate and national highways. These corridors include thousands of square miles of medians, shoulders, and adjacent land that currently serve little purpose beyond separating traffic and providing emergency stopping zones. This extensive network of untapped real estate represents one of the largest contiguous publicly-owned land resources in the country—land that receives consistent sunlight throughout the day and remains largely undeveloped.

While these roadside spaces have traditionally been viewed as merely functional components of transportation infrastructure, a growing movement sees them as something much more valuable: potential sites for large-scale solar energy production. Imagine driving between cities with the center medians and side margins of highways covered with sleek solar panels, silently generating clean electricity while cars pass by. This concept, known as roadside solar or highway solar farming, transforms unused public land into productive energy-generating assets.

The potential is significant. According to research from the Ray C. Anderson Foundation, if all suitable highway right-of-way areas in the continental United States were equipped with solar panels, they could generate an estimated 36 terawatt-hours of electricity annually—enough to power over 3 million homes. With the United States aiming to achieve energy independence while reducing carbon emissions, highway solar is a practical pathway that leverages existing infrastructure rather than developing new greenfield sites.

Highway solar installations offer an opportunity to advance American energy independence through distributed power generation. Unlike conventional solar farms that require dedicated land acquisition, roadside solar utilizes existing publicly-owned space, eliminating land procurement costs and minimizing disruption. By implementing solar along our highway system, we can create a nationwide network of clean energy production that reduces our reliance on imported fuels and centralized power systems, while building resilience against natural disasters and security threats to our energy infrastructure.

As we face the dual challenges of climate change and energy security, roadside solar offers a practical solution that maximizes the use of existing infrastructure while moving us toward a more independent energy future. The technology exists today—the question is whether we have the vision and will to transform our highways from mere transportation corridors into productive contributors to our nation’s energy needs.

What Are Roadside Solar Farms?

Roadside solar farms are an innovative approach to renewable energy deployment that utilizes the network of highway medians, shoulders, embankments, and adjacent right-of-way lands to generate clean electricity. Unlike traditional solar installations that require dedicated land parcels, roadside solar farms integrate photovoltaic technology directly into existing transportation infrastructure, creating dual-purpose land use that maximizes public resources.

These installations transform unproductive spaces into renewable energy powerhouses. The concept extends beyond placing panels along roadsides; it encompasses an approach to infrastructure design that merges transportation and energy production into a unified system. Modern roadside solar implementations include everything from standalone panel arrays along highway margins to solar-embedded noise barriers, energy-generating guardrails, and even experimental solar road surfaces.

How Roadside Solar Systems Work

The technology behind roadside solar farms mirrors conventional solar installations, with photovoltaic panels converting sunlight into electricity. Highway solar applications introduce several design considerations to address their unique environment.

Most roadside solar systems connect to the electrical grid through nearby transmission infrastructure, utilizing existing utility corridors that parallel major highways. The electricity generated feeds directly into the grid, offsetting conventional power production and potentially powering nearby facilities like rest areas, toll plazas, highway lighting, and electric vehicle charging stations.

The implementation approach varies depending on site-specific factors:

• Median installations: In wide highway medians, panels are mounted on ground-based racking systems, with specialized foundations designed to withstand vibration from passing vehicles. These installations include safety barriers to protect both the equipment and motorists.
• Shoulder and embankment arrays: Solar panels installed on roadside embankments often use terrain-following mounting systems that conform to the existing topography, minimizing the need for grading or extensive site preparation.
• Integrated infrastructure: Some designs incorporate solar capabilities directly into existing highway elements like sound barriers that generate power while reducing noise pollution or guardrails that serve both safety and energy production functions.
• Specialized configurations: To minimize driver distraction and prevent glare, roadside installations often use anti-reflective coatings and carefully calculated panel angles. Some systems incorporate tracking mechanisms that follow the sun’s path throughout the day, maximizing energy production while maintaining safe viewing angles for drivers.

The electrical systems include inverters that convert the DC power from the panels into grid-compatible AC electricity, as well as monitoring equipment that allows remote management and performance tracking. Many installations feature cutoff mechanisms that can rapidly disconnect the system in the event of accidents or emergency situations.

Existing Implementations Around the World

Roadside solar is moving from concept to reality across the globe, with successful implementations demonstrating its viability:

United States:

• The Ray Highway in Georgia is a living laboratory for roadside solar implementation, featuring a 1-megawatt installation along Interstate 85. This project includes EV charging stations powered directly by the highway’s solar arrays.
• Massachusetts has pioneered multiple highway solar installations, including a notable project along Route 44 in Carver, where solar canopies were constructed above an existing highway rest area, generating electricity while providing covered parking.
• Oregon’s Solar Highway Program, launched in 2008, installed a 104-kilowatt system near the interchange of Interstates 5 and 205, generating approximately 128,000 kilowatt-hours annually—enough to power about 12 average Oregon homes.

Europe:

• Germany has been a frontrunner in roadside solar adoption, with substantial installations along the A3 near Aschaffenburg. These systems integrate with noise barriers, performing dual functions of sound reduction and power generation.
• The Netherlands has implemented solar bike paths and roadways, including the SolaRoad project, which embeds solar cells within the road surface itself, demonstrating the potential for direct integration of solar technology into transportation surfaces.
• In Switzerland, a 500-meter solar noise barrier along the A13 highway in Chur generates approximately 30 megawatt-hours of electricity annually while reducing traffic noise for nearby residents.

Asia:

• South Korea has constructed a 20-mile solar bike lane in the middle of a highway between Daejeon and Sejong, generating power while providing protected transportation infrastructure for cyclists.
• China has deployed extensive roadside solar, including a massive 100-megawatt solar highway in Jinan, Shandong Province, which incorporates transparent concrete layers over solar panels embedded directly in the roadway.
• Japan has implemented several highway solar projects, including installations along the Tomei Expressway that power nearby service areas and contribute excess electricity to the national grid.

As solar technology continues to advance with higher efficiency panels, improved energy storage solutions, and decreasing installation costs, the case for roadside solar becomes more compelling. The existing implementations around the world demonstrate not only technical feasibility but also practical economic viability, paving the way for wider adoption across global transportation networks.

Benefits of Highway Solar Installations

Highway solar installations offer advantages that go beyond electricity generation. From environmental conservation to economic growth and infrastructure resilience, roadside solar is one of the most efficient ways to deploy renewable energy at scale without the drawbacks associated with dedicated solar farms. Let’s explore the benefits this approach delivers.

Environmental Advantages

Reduced Carbon Emissions

Highway solar installations make a contribution to carbon emission reduction by generating clean electricity that displaces fossil fuel-based power generation. The environmental impact is substantial:

• A single mile of highway solar can prevent approximately 400-800 metric tons of carbon dioxide emissions annually, depending on the local electricity generation mix it replaces. For perspective, this is equivalent to removing 87-174 passenger vehicles from the road each year.
• When implemented across the entire interstate highway system, roadside solar could reduce U.S. carbon emissions by an estimated 35 million metric tons annually—equivalent to closing 9 coal-fired power plants or planting 41 million acres of forest.
• The carbon payback period for highway solar installations (the time required for the clean energy produced to offset the emissions from manufacturing and installing the panels) is typically less than three years, while the systems continue producing clean energy for 25-30 years.
• Unlike traditional power plants that produce emissions throughout their operational lifetimes, highway solar systems generate zero operational emissions after installation, meaning their environmental benefits compound year after year.

Land Conservation and Habitat Protection

One of the main benefits of highway solar is its minimal land-use impact:

• By using existing transportation corridors, highway solar eliminates the need to clear undeveloped land for energy production, preserving natural habitats and agricultural areas. Traditional utility-scale solar requires approximately 5-10 acres per megawatt, whereas highway solar leverages already-disturbed land within the transportation footprint.
• The Ray C. Anderson Foundation estimates that using just 30% of suitable highway right-of-way areas for solar could generate as much power as 45,000 acres of dedicated solar farms, effectively conserving that land for agriculture, wildlife, or other uses.
• Properly designed highway solar installations can enhance roadside ecosystems through landscaping with native plants that support pollinators and wildlife, creating green corridors connecting fragmented habitats.
• Studies from the University of Minnesota have shown that strategic solar development along highways can reduce roadside maintenance costs while creating habitat for threatened pollinators like bees and butterflies, contributing to biodiversity conservation.

Water Conservation

Solar energy’s water efficiency represents another environmental advantage:

• Unlike thermoelectric power plants (including coal, natural gas, and nuclear) that require 20-60 gallons of water per kilowatt-hour for cooling, highway solar systems require virtually no water for operation beyond occasional cleaning.
• When implemented at scale, highway solar could save billions of gallons of water annually compared to conventional electricity generation, contributing to water conservation efforts, especially in drought-prone regions.
• The minimal water requirements of highway solar make it well-suited for arid regions where water resources are already strained by population growth and climate change.

Economic Benefits

Job Creation and Economic Development

Highway solar creates employment opportunities across various sectors:

• The Solar Energy Industries Association (SEIA) estimates that each megawatt of solar installation creates approximately 18 job-years, including direct construction, manufacturing, and support roles. Applied to highway solar potential, this could generate hundreds of thousands of jobs nationwide.
• Unlike many infrastructure investments, highway solar creates diverse employment opportunities across education levels, from installation and maintenance positions requiring technical certification to engineering and project management roles requiring advanced degrees.
• Highway solar projects create strong local job benefits, as installation, operation, and maintenance must occur on-site and cannot be outsourced. A study by the Political Economy Research Institute found that solar investments create more than twice as many jobs per dollar invested compared to fossil fuel projects.
• The distributed nature of highway solar installations means job creation is spread throughout regions rather than concentrated in a single location, providing economic development opportunities for rural and suburban communities near highway corridors.

Reduced Energy Costs and Revenue Generation

Highway solar delivers financial returns for state transportation departments and taxpayers:

• States like Massachusetts have leased highway right-of-way areas to solar developers, generating new revenue streams of $15,000-$50,000 per acre annually without capital investment by the state. Oregon’s Solar Highway Program demonstrated similar financial benefits, creating positive cash flow for the Department of Transportation.
• Highway solar installations can provide electricity directly to power roadway lighting, signage, and operations centers at rates 30-50% below retail utility prices, reducing operational costs for transportation departments. Georgia’s Ray Highway project demonstrated savings of approximately $12,000 annually for a single mile of highway.
• Power purchase agreements (PPAs) between transportation departments and solar developers can lock in electricity rates for 20+ years, providing budget predictability and insulation from fossil fuel price volatility.

The benefits of highway solar installations make them one of the most compelling approaches to renewable energy deployment available today. By addressing environmental challenges, creating economic opportunities, enhancing infrastructure functionality, and strengthening energy security, roadside solar becomes an efficient use of public resources As technology improves and implementation experience grows, the case for transforming our highways into energy-generating assets becomes persuasive for policymakers, transportation officials, and the public alike.

Challenges and Considerations

While highway solar installations offer many benefits, implementing these systems comes with challenges that require careful planning and innovative solutions. Understanding these obstacles is crucial for developing successful roadside solar projects that maximize benefits while minimizing risks to transportation infrastructure, public safety, and environmental integrity.

Maintenance and Safety Concerns

Maintaining solar arrays along busy highways presents unique challenges not encountered in traditional solar installations. Highway departments have to balance the need for regular panel cleaning, equipment inspection, and repairs with the safety of maintenance personnel and passing motorists. Access to installations often requires lane closures, creating traffic disruptions and potential hazards, particularly on high-speed corridors with limited shoulders.

Solar arrays must also be carefully designed to prevent unwanted glare that could temporarily blind motorists. This challenge has prompted the development of advanced anti-reflective coatings and glare analysis software that simulates sunlight reflection throughout the year to identify and reduce hazards before construction begins.

The potential for vehicle collisions with roadside equipment presents another safety consideration. Highway solar installations require protective barriers, particularly in high-speed corridors where vehicles occasionally leave the roadway. The Georgia Department of Transportation addressed this challenge in their Ray Highway project by installing guardrails and crash attenuators around solar equipment, with panel setbacks calculated based on traffic speed and volume to minimize collision risks.

Innovative solutions to these maintenance and safety challenges are emerging. For example, the Massachusetts Department of Transportation has pioneered the use of drones for solar array inspection, reducing the need for personnel on the ground and minimizing traffic disruption. Some newer installations feature automated cleaning systems that use minimal water resources and operate during nighttime hours when traffic volumes are lower, addressing maintenance efficiency and safety concerns simultaneously.

Potential Traffic and Visibility Issues

Visual distraction remains one of the main concerns for highway solar installations. Research by the Federal Highway Administration suggests that new or unusual roadside elements can temporarily capture driver attention, increasing crash risk if not properly managed. It’s necessary for transportation officials to carefully balance energy generation potential with the safety requirements of the highway environment.

Line-of-sight issues can arise when solar installations interfere with drivers’ ability to see oncoming traffic, particularly at interchanges, curves, and other decision points. These visibility concerns have led to design guidelines in several states that prohibit installations within specific distances of ramps, merges, and other high-risk areas. Oregon’s Solar Highway Program developed siting criteria that exclude areas with potential sight-line conflicts, providing a model approach that preserves safety while maximizing suitable installation locations.

Computer modeling has become essential for predicting glare impacts throughout the year and across different weather conditions. The Federal Aviation Administration’s Solar Glare Hazard Analysis Tool, originally developed for airports, has been adapted for highway applications to identify and address problem spots before installation begins. Some installations now incorporate dynamic tilt systems that adjust panel angles throughout the day to maintain energy production while eliminating dangerous reflection angles.

Project designers have found creative solutions to these visibility challenges by integrating solar installations more harmoniously with the roadside environment. In Switzerland, solar noise barriers feature artistic elements that break up the visual monotony while still generating substantial power. The Massachusetts Highway Division has experimented with landscaping techniques that frame solar installations within the existing roadside vegetation, reducing their visual prominence while maintaining energy output.

Weather and Environmental Impacts on Panels

Highway solar installations face more extreme environmental conditions than typical ground-mounted systems. Vibration from passing vehicles can stress mounting systems and electrical connections over time, leading to premature component failure if not properly engineered. Recent installations address this issue through reinforced mounting structures and vibration-dampening technologies adapted from other industries where equipment needs to withstand continuous motion.

Extreme weather events pose significant challenges for roadside solar, as highway corridors experience more severe wind conditions due to their open setting and the channeling effect of the roadway itself. High wind loads require stronger foundations and support, increasing installation costs. Engineers have responded with aerodynamic designs that reduce wind resistance while maintaining structural integrity, drawing inspiration from buildings designed for hurricane-prone regions.

Winter weather creates multiple challenges for highway solar. Snow accumulation can cover panels and reduce or eliminate energy production, while snow plowing operations can damage equipment through direct impact or thrown debris. The Minnesota Department of Transportation addressed these issues in their highway solar pilot by elevating panels well above maximum snow depth and installing protective barriers designed to deflect snow and ice thrown by plows without blocking sunlight.

Temperature fluctuations in the highway environment tend to be more extreme than in typical solar installations due to heat radiating from the roadway surface and the lack of surrounding vegetation that might moderate temperatures. This thermal cycling can reduce panel efficiency and accelerate the aging of electrical components. Some installations incorporate passive cooling design features like elevated mounting systems that promote air circulation, helping to maintain operating temperatures even during extreme heat events.

The complexity of these challenges should not discourage pursuit of highway solar projects. Rather, they highlight the need for thoughtful approaches that address technical and operational concerns from the earliest planning stages. By learning from successful implementations and continuing to develop innovative solutions, the obstacles to widespread adoption of highway solar can be addressed, unlocking the benefits these systems offer while maintaining the safety and functionality of our transportation infrastructure.

Technology and Innovation in Highway Solar

The intersection of solar power and transportation infrastructure has become a hotbed of technological innovation, with solutions emerging to address the challenges of the highway environment. From advanced panel designs that maximize energy capture while minimizing driver distraction to integrated systems that perform multiple functions, the technology powering roadside solar is evolving. Looking ahead, emerging technologies will enhance the benefits of these installations, transforming our highways into true clean energy corridors.

Cutting-Edge Solar Technologies 

Traditional solar panels are just the beginning when it comes to roadside solar implementation. Today’s highway-specific installations incorporate a range of technologies optimized for the unique challenges of transportation corridors. Bifacial solar panels, which capture sunlight from both their front and rear surfaces, have proven valuable in highway applications. These panels can harness direct sunlight and light reflected from roadway surfaces, increasing energy yield by 5-30% compared to traditional monofacial panels without requiring additional land area.

Solar noise barriers have become one of the most successful applications for highway solar. These dual-purpose installations replace conventional concrete or wooden sound walls with photovoltaic-integrated barriers that generate electricity while reducing traffic noise for adjacent communities. The Federal Highway Administration estimates that if just 25% of existing noise barriers nationwide were retrofitted with solar technology, they could generate over 400 gigawatt-hours of clean electricity annually. In Europe, companies like Kohlhauer have pioneered transparent solar noise barriers that allow light to pass through while still generating power, preserving views, and reducing the visual impact on surrounding neighborhoods.

Thin-film solar technologies have found application in highway settings because of their flexibility, lighter weight, and superior performance in diffuse light conditions. Unlike rigid crystalline panels, thin-film applications can be contoured to follow the existing topography of roadside embankments or integrated directly into infrastructure elements like guardrails and signage. The Swiss company Flexcell has developed rollable solar sheets designed for infrastructure applications, allowing installation on curved surfaces where traditional panels would be impractical.

Anti-glare technologies have also advanced, addressing one of the primary safety concerns associated with roadside solar. New anti-reflective coatings can reduce reflection to less than 2% across the solar spectrum, virtually eliminating glare for drivers. Some manufacturers now produce panels with textured surfaces that diffuse reflected light, further reducing distraction while maintaining energy production.

Energy storage integration is becoming a standard feature of highway solar installations, allowing these systems to provide power consistently regardless of cloud cover or time of day. Battery systems installed at strategic locations along highway corridors enable excess daytime production to power nighttime lighting and signage, creating truly self-sufficient transportation infrastructure. In Oregon, battery storage systems paired with highway solar installations provide emergency backup power for roadway systems during grid outages, enhancing safety.

Specialized Designs for Highway Applications

The harsh realities of roadside environments have driven the development of specialized mounting systems engineered for highways. These systems must contend with wind loads amplified by the channeling effect of highways, vibration from passing vehicles, impact from debris, and exposure to road salt and other deicing chemicals. Companies like Solar Highway Systems have developed mounting structures with enhanced corrosion resistance and vibration dampening features that extend the operational lifespan of roadside installations.

Vertical solar arrays have emerged as an effective configuration for highway medians and narrow rights-of-way. Unlike conventional tilted arrays that require more lateral space, vertical installations can fit within constrained corridors while still generating substantial power. Researchers at the Massachusetts Institute of Technology have found that in northern latitudes, dual-facing vertical panels can deliver more consistent energy production throughout the day compared to conventional tilted arrays, with peak production occurring during morning and evening hours when electricity demand is highest.

Aesthetically integrated designs help address public concerns about visual impact while maintaining energy production. In the Netherlands, solar sound barriers along the A2 highway incorporate artistic elements and undulating forms that complement the surrounding landscape. Similar approaches in Austria have led to solar installations that function as public art, transforming potential eyesores into community assets. These design innovations help overcome one of the barriers to public acceptance of highway solar: concerns about visual pollution along scenic corridors.

Emerging Technologies

Perhaps the most exciting developments in highway solar come from the convergence of multiple technologies into systems that deliver benefits beyond simple power generation. Smart highways combine solar power generation with intelligent transportation systems, dynamic lighting, and weather monitoring to create safer, more efficient corridors. The Ray Highway in Georgia demonstrates this approach, using solar energy to power sensing systems that provide real-time traffic and environmental data while feeding clean electricity back to the grid.

Electric vehicle charging infrastructure powered directly by adjacent solar arrays creates true zero-emission transportation corridors. Companies like EVgo have begun deploying solar canopies above charging stations along major highways, providing clean energy for charging and weather protection for users. As electric vehicle adoption accelerates, these solar-powered charging networks will become more important for long-distance travel, especially in rural areas where grid capacity is limited.

Wildlife protection systems powered by roadside solar are addressing the impact of highway corridors. Solar-powered wildlife crossing sensors can detect animal movement and activate warning systems for approaching motorists, reducing collisions and protecting wildlife and human travelers. In regions with endangered species, these systems have demonstrated significant reductions in roadkill incidents, showing how highway solar can contribute to ecological restoration even within developed transportation corridors.

The technology driving highway solar continues to advance, with innovations emerging from fields as diverse as materials science, computer engineering, transportation safety, and ecological design. The highways of tomorrow will likely be not just transportation corridors but dynamic, multifunctional infrastructure that contributes to our energy needs while enhancing safety, resilience, and environmental sustainability.

The Road Forward

As we look across the vast network of highways that connect our communities, we can now envision something more than just transportation corridors. These ribbons of public land have become one of our greatest untapped opportunities for renewable energy generation—a resource hiding in plain sight that could help power America’s clean energy transition without sacrificing additional land.

Highway solar installations offer a vision of infrastructure that serves multiple purposes. By transforming medians, shoulders, embankments, and noise barriers into energy-generating assets, we can make our transportation network work harder for us, producing clean electricity while continuing to fulfill its main mission of connecting people and goods across the country.

The technology is always advancing, with innovations like bifacial panels, vertical arrays, and integrated energy storage expanding the possibilities for highway solar deployment. As these technologies mature, the case for transforming our highways into energy corridors grows stronger by the day.

Partner with 8MSolar for Your Solar Journey

Whether you’re inspired by the potential of highway solar or looking to harness the power of the sun for your home or business, 8MSolar is your trusted partner in solar energy solutions. As North Carolina’s premier solar provider, we bring expertise, quality products, and unmatched service to every project. Our team of certified professionals understands how to maximize energy production within the constraints of available space, optimize system performance for local conditions, and create seamless integration with existing infrastructure.

The transition to renewable energy happens one project at a time, with each installation contributing to a cleaner, more sustainable energy future. By working with 8MSolar, you’re not just investing in your own energy independence—you’re joining a movement toward a more resilient, sustainable energy system for all.

Don’t wait for the highways around you to transform into solar corridors. Take the first step toward your own clean energy future today. Together, we can build a brighter, cleaner future powered by the unlimited energy of the sun.