Right-of-way Solar
Photo: David Arnold at GPS Studios
“We have unlimited, renewable power from that marvelous fusion reactor eight minutes away at the speed of light to tap into and distribute from one end of our country to the other.”Ray C. Anderson, 2008
State departments of transportation (State DOTs) own and maintain significant land areas along highways. These “right-of-way” (ROW) areas are appealing locations for renewable energy development for many reasons including:
- unshaded acreage
- ease of access
- public ownership status
- lack of competing development efforts
Renewable energy development along our roadsides has the potential to help states reduce their energy costs, reduce their land maintenance costs, increase resilience and local energy security, create new revenue streams, and meet broader renewable energy and greenhouse gas emission targets. The U.S. Department of Transportation and the Federal Highway Administration issued guidance for alternative uses of the highway ROW that can be leveraged by State DOTs for pressing public needs relating to climate change, equitable communications access and energy reliability. To learn more about how to structure these beneficial highway solar projects, visit the 2020 research report, developed by the Webber Energy Group (WEG) at UT Austin in partnership with The Ray: The Ray Highway Project: Assessment of solar potential installed in ROWs across the U.S.
Advanced ROW Mapping Tool with Esri
In 2021, Esri gifted The Ray a sophisticated ROW solar mapping tool, using its ArcGIS Pro software suite. The tool includes advanced 3D modeling, solar radiation calculations based on digital elevation and surface models, digital twins, and viewshed analysis. This is a powerful resource that can be used for faster and more precise analysis of ROW solar, PV installation suitability and economic value that is capable of producing precise configurations of solar arrays on all types of ROW, utilizing State DOTs’ full spatial ROW data sets. Esri is the natural facilitator and accelerator of this work because they are already a trusted partner of State DOTs.
Esri’s solar mapping tool, presented by The Ray, has the ability to:
- Assess which ROW land areas are most suitable for solar development by taking into account slope, elevation, vegetative cover, and solar radiation.
- Automate key aspects of planning by filtering State DOTs’ ROW data sets using exclusion and inclusion layers, which accounts for sensitive lands such as wetlands, areas around existing infrastructure, and threatened and endangered species habitat.
- Evaluate solar radiation of the areas by using local or regional and season-specific data.
- Calculate the economic value of the solar energy using local or regional utility data, and produce other beneficial environmental values, such as the equivalencies of the solar energy generation expressed as reductions in CO2 and number of vehicles driven.
Video: Highlights from the Esri ROW Solar Mapping Tool presented by the Ray
The Esri solar tool’s cutting-edge digital twin technology also enables State DOTs and other transportation operators to:
- Anticipate unintended consequences to nearby communities of installing solar on the roadsides of interstates and highways, such as the interruption of a scenic viewshed.
- Engage in preliminary planning exercises digitally with the tool, including the ability to alter the shape, size or scope of any solar array in order to navigate or neutralize a potential social impact, and then compare the economics of various planned scenarios.
Several states have already developed "solar highway" projects, including Oregon, Massachusetts, Maryland, and Georgia. In 2020, the Georgia Power Company commercialized a one-megawatt solar array at Exit 14 of The Ray Highway. Georgia is the third state in the nation to utilize the highway roadsides for renewable energy development. The project on The Ray Highway also uses native, flowering plants as ground cover within the solar array, making Georgia the first in the nation to install pollinator-friendly ROW solar.
Video: David Arnold at GPS Studios
Map of Highway Renewable Energy Projects in the U.S.
If you work or are involved with a transportation agency and would like to schedule a demonstration of the solar mapping tool with The Ray, please email contactus@theray.org.
Resources from Federal and State DOTs
- State DOTs Leveraging Alternative Uses of the Highway Right-of-Way Guidance
- Caltrans Solar Report
- Oregon DOT “Solar Highway Program: From Concept to Reality”
- MassDOT Solar Energy Program
- Solar Program at Maryland DOT
- Assessment of Colorado DOT Rest Areas for Sustainability Improvements and Highway Corridors and Facilities for Alternative Energy Source Use
- FHWA Quick Guide: Requirements for Renewable Energy Projects in Highway ROW
- FHWA Guidance on Utilization of Highway ROW
- FHWA Highway Renewable Energy: Photovoltaic Noise Barriers research
- MnDOT Solar Program
Other Resources
- NextGen Highways: Co-Locating the Transport of Vehicles, Energy, and Information
- Terms, Trends, and Insights on PV Project Finance in the United States, 2018
- FHWA Renewable Energy in Highway ROW homepage
- Database of State Incentives for Renewables & Efficiency (DSIRE)
- State Smart Transportation Initiative: Requests for Proposals and Similar Documents
- Solar Renewable Energy Credit Trading Markets
- NREL State, Local & Tribal Governments Renewable Energy Resources
- A Guide to Community Shared Solar: Utility, Private, and Nonprofit Project Development
- SEIA Power Purchase Agreements
- NREL Interactive Solar PPA Widget
- SEIA Model Leases and PPAs
- Solar Power Purchase Agreements: A Toolkit for Local Governments
- PPA Checklist for State and Local Governments
- Steps to a Successful Solar Request for Proposal
- Writing Solar RFPs: Lessons from NREL’s University PV Implementation Assistance Program
- Federal On-Site Renewable Power Purchase Agreements
- Sample Documents for Federal On-Site Renewable Power Purchase Agreements
- NREL RFP Template for Grid-Tied Solar PV Systems for State/City
- FHWA Solar Energy Use
- FERC Regulatory Considerations for Developing Generation Projects on Federal Lands
- Solar PV PPA Prices: Lawrence Berkeley National Laboratory Provides an interactive data set of the PPA prices for utility-scale solar projects since 2006
- Wind PPA Prices: Lawrence Berkeley National Laboratory provides an interactive data set of wind power purchase agreement prices since 1997 by region
- FAA Notice Criteria Tool
- Technical Guidance for Evaluating Selected Solar Technologies on Airports
