What did the State of Minnesota learn about building solar on closed landfill sites?
Potential for 950 MW of solar on 4,500 acres
By Dan Thiede
In 2019, the Minnesota Legislature allocated funding to the Environmental Quality Board to study the potential for solar development on Minnesota’s Closed Landfill Program sites. Solar development on these sites would put underutilized, contaminated land to use generating clean energy, reducing greenhouse gas emissions, and creating jobs and revenue. Siting solar on brownfields like closed landfills—called "brightfield" development—can also reduce development pressure on other lands, such as farmland and natural areas. The Environmental Quality Board delivered a report to the legislature in December 2020, and data about Closed Landfills Program sites is now available.
Identification and assessment of properties in the closed landfill program with the highest potential for solar energy production
Identification of potential barriers to solar energy production and potential ways to address those barriers
Policy recommendations that would facilitate solar energy production on closed landfill program sites in a manner that would contribute to state and local government sustainability goals
Solar potential: There is significant technical potential for solar development on Minnesota’s CLP sites. The technical assessment estimated that there is potential to generate 950 megawatts AC (MW) using solar on 4,500 acres in the CLP, or enough to power over 100,000 homes.
Barriers: Several barriers limit solar development on CLP sites.
The current statutory mission of the CLP is limited to taking environmental response actions and protecting human health and the environment. Establishing beneficial property reuse was not included and funded in the original CLP program mission.
Fifty-five CLP sites have use restrictions because of past general obligation bond financing of cleanup actions. The prospects for beneficial reuse, including solar development, are limited for property where bond financing was used until the bonds are retired.
Solar development could be more costly and complex on closed landfills than on greenfield (uncontaminated) sites. Solar developers face uncertainty about site-specific suitability for solar, increased costs associated with construction on the landfill cap, as well as real and perceived risks associated with CLP responsibilities.
State regulations impose limitations on solar projects under some solar ownership, operation, and program models. For example, new Community Solar Garden projects are limited to 1 MW, which is well below the estimated solar energy generation capacity of many CLP sites. Legislative action would be required to raise this limit at brownfield locations such as CLP sites.
Expand statutory authority of the CLP to authorize and fund proactive work on property reuse, including solar development, and provide funding to establish a Closed Landfill Beneficial Reuse Program.
The CLP is able to enter into leases when there is an expressed interest in leasing state property, provided the proposed land use is appropriate. However, CLP is not authorized or funded to proactively facilitate beneficial property reuse. With increased authority and resources, the CLP could facilitate beneficial reuse, including solar development on state-owned sites, and develop guidance for local government- and privately-owned sites.
Development of a Closed Landfill Beneficial Reuse Program would require further investigation into several topics, including solar ownership models, incentives, lease revenue uses, Solar Renewable Energy Certificate ownership, and interconnection costs. Continued interagency collaboration would be necessary to develop a Closed Landfill Beneficial Reuse Program aligned to the State’s economic, equity, environmental justice, and environmental goals.
Appropriate funds to retire bond debt early and legislatively authorize the release of state bonding restrictions for select CLP sites. Freeing property from bond restrictions would open up lands for solar development and could generate significant revenues into the future.
Presentation about Minnesota Brightfields Study results
Barr Engineering developed an interactive mapping tool as part of the feasibility study contract with the Environmental Quality Board in 2020. Use this tool to search for information about specific Closed Landfill Program sites, transmission lines, substation locations, and other public data.
Access the Minnesota Brightfields Study report and related resources