Image: E2SOL / By James Reid, Environmental Science Analyst

As climate change accelerates and energy demands continue to increase, innovative solutions to generate sustainable solar power are essential in today’s race to lower greenhouse gas emissions and air particle matter for healthier ecosystems. In the State of Rhode Island, local municipalities wrestle with solar permit applications and ordinances that restrict the installation of utility-scale solar systems in landscapes as well as some residential zones. Yet, the State of Rhode Island’s 2021 Act on Climate law, signed on April 21, 2021, establishes the requirements for the State to achieve Net-Zero Greenhouse Gas Emissions by 2050 (1).

I was recently captivated by the Rhode Island-based company E2SOL’s “Smart Solar Highway” Project when I stumbled upon it on their website during a recent web search. The idea of transforming something as mundane as highway concrete barriers into a source of renewable energy felt like a glimpse into the future—especially knowing that the State is developing Electric Vehicle Charging (EVC) stations off our highways under the RI NEVI program funded by the National Transportation Agency (2). That inspiration led me to dive into an independent study exploring how this concept could work in Rhode Island. Why Rhode Island? It is the perfect testing ground. The State is small and densely connected, making it an ideal place to prove the potential of solar-powered highways that can support local power utilities. My goal was to take this innovative concept and see if I could map it onto Rhode Island’s highway barriers to create a practical and impactful solution for renewable energy generation in the State without the need to displace pristine landscapes or conflict with local municipal solar permit ordinances.

Background

Highways contribute significantly to carbon emissions from vehicular traffic. Installing solar modules on existing concrete barriers provides us with a dual solution: harnessing renewable energy and mitigating greenhouse gas emissions. Solar modules in the right-of-way have been conceptualized before. Numerous projects around the world have been carried out, each with its unique traits. Notable examples include France’s Wattway, which aimed to install modules into the roadway itself, and Switzerland, which has initiated solar cell installation on highway noise barriers. These projects encountered barriers such as considerable wear and tear and unsafe glare during specific sun lighting periods, respectively. Downregulated efficiency and unsafe conditions for drivers will not be a factor for E2SOL’s Smart Solar Highway Project due to design specifications preventing drivers’ sightline to and direct contact with all solar modules.

Technological Integration and Energy Resilience

A Smart Solar Highway project demonstrates the integration of advanced technology with existing dormant infrastructure to produce renewable energy and improve grid power resiliency. Solar modules would be mounted in series on structural brackets fixed to existing concrete barriers, much like highway lighting poles are mounted in some regions. Rhode Island’s 73.2 miles of concrete barriers (approximately 386,542 linear feet) present significant opportunities for solar highway median barrier installations.

If all possible existing concrete median assets are used, a modular system comprising high-wattage solar modules (i.e., 635 watts) with integrated energy storage capability of 1 kilowatt per module projects to generate approximately 65,931 Megawatt Hours (MWh) annually (5). The ability to store 32,965 MWh surplus energy ensures power availability during off-peak hours in the evening or during adverse weather conditions due to New England’s weather variability. Modular designs further increase resilience, ensuring uninterrupted energy for critical services like Electric Vehicle Charging (EVC) stations, highway lighting, and traffic systems’ electrical demands. The estimated energy generation could power approximately 9,307 Rhode Island households annually (3).

RI Suitable Highway Median Concrete Barriers (shown in Violet)

Energy Savings and Reducing Carbon Footprints

The smart solar highway system’s energy generation (estimated 65,931 MWh annually) could significantly bolster Rhode Island’s renewable energy resources. For context, Rhode Island’s total direct electricity demand in 2023 was 222 MWh (4). This project alone could contribute to offsetting 30% of that power demand, significantly reducing dependence on grid-based electricity and other fuel sources (e.g., gas). If this innovative product system were to be implemented, the RI Department of Transportation could offset an estimated 65,931 MWh annually under the RI Net Metering program, helping to achieve cost savings estimated at $14.25M (based on Rhode Island’s 2023 average electric retail sales cost of $0.2162/kWh) (4). It could also generate annualized revenue by selling its renewable power to the Utility under a 20-year Power Purchase Agreement Program (Tariff Incentive), or it could sell its renewable power to local community residents at a lower cost than private utilities, helping local communities save on their electric cost expenses. Integrating energy storage allows energy export during peak demand periods. It can also deliver power in times of utility power outages from extreme climate events. The scalability of the system into municipalities could provide long-term cost savings and revenue opportunities for municipalities as well.

This Rhode Island Smart Solar Highway system offers the potential to offset 29,104 metric tons of Carbon Dioxide (CO2) annually. This is equivalent to greenhouse gas emissions from (3):

• 6,789 gasoline-powered passenger vehicles driven for one year
• 8.7 wind turbines running for a year
• 29,193 acres of U.S. forests in one year
• 3,274,868 gallons of gasoline consumed

Impact on Operational Efficiency and Public Image

The Smart Solar Highway system enhances operational efficiency by reducing reliance on external energy supplies and improving resilience during grid disruptions. Critical infrastructure, such as EVC stations and highway lighting, can remain operational even during peak demands or outages.

Implementing such infrastructure also strengthens Rhode Island’s public image as a leader in sustainable transportation and clean energy innovation. It aligns with government and public expectations for climate change mitigation while serving as a replicable model for other regions.

Equity and Accessibility

Communities near highways, especially Environmental Justice Communities (EJCs), often experience higher pollution levels and lack access to clean transportation solutions. This project ensures these communities benefit from renewable energy infrastructure, improving overall quality of life and access to clean energy options.

Transportation inequities persist due to the high upfront cost of EVs and limited charging infrastructure in lower-income urban areas. Without targeted investments, these communities remain excluded from the economic, health, and environmental benefits of electric vehicles. Notably, Rhode Island’s highway concrete barriers are located within a 4-mile radius of disadvantaged communities in all cases, according to CJEST. As such, the benefits of the Smart Solar Highway project are poised to positively impact a significant portion of Rhode Island’s population, with a particular emphasis on EJCs.

Conclusion

The Rhode Island Smart Solar Highway project is more than a technological innovation—it’s a visionary step toward a sustainable future. By leveraging existing dormant infrastructure, this initiative offers a scalable solution to address climate change, reduce carbon footprints, and generate renewable energy. Beyond its environmental benefits, the project fosters social equity, enhances energy resilience, and positions Rhode Island as a leader in clean energy and sustainable transportation. Its success could serve as an inspiring model for other states and regions, proving that transformative change is achievable when creativity meets purpose. Together, we can pave the way for a brighter, cleaner tomorrow.

Sources

(1) https://climatechange.ri.gov/act-climate

(2) NEVI2 – https://energy.ri.gov/transportation/ri-nevi-program/ri-nevi-plan-roadmap

(3) https://www.epa.gov/energy/greenhouse-gas-equivalencies-calculator#results

(4) https://www.eia.gov/electricity/state/rhodeisland/

(5) Department of Energy PV Watts Model