Strategic Solar Siting in Murray County, Minnesota

As solar acreage grows, the potential for conflict between competing land uses may also grow. Being able to clearly demonstrate both financial and environmental benefits may mitigate some of these conflicts and increase the public acceptance of solar PV as a land-use development option.

There has been much interest in mid-scale solar at local levels identified through meetings of the  Rural Minnesota Energy Board , as well as at meeting opportunities with  CERTs . This project intends to illuminate the desires of local stakeholders to inform the emphasis and evaluation metrics of potential future solar installations.

 Southwest RSDP  launches education and research that help people understand and achieve sustainability across southwestern Minnesota. This partnership supports projects that demonstrate public purpose and build partnerships with residents of the region, and link these projects to local assets and University of Minnesota research and educational resources.

From Fall 2020 to Spring 2021, the  University of Minnesota Institute on the Environment ,  The Southwest Regional Development Commission , the  Great Plains Institute  and the  Clean Energy Resource Teams  formed a partnership to work through RSDP's project process to investigate opportunities to develop solar energy installations in Southwest Minnesota, and specifically Murray County, with considerations of both solar co-benefits and community input.

Source:  Public Waters Basin and Watercourse Delineations 

This analysis begins with the placement of the DNR-Classified Public Waters Basin and Watercourse Delineations. This layer includes lakes, ponds, flowage, rivers and streams.

To see a legend of this data layer, click on the Legend Icon found on the bottom left of this map.

 To account for local siting regulations , a 300-foot buffer (perimeter) was established surrounding the streams and rivers, and a 1000-foot buffer was established surrounding the lakes, ponds and flowage.

To see a legend of this data layer, click on the Legend Icon found on the bottom left of this map.

Source:  Minnesota Roads, 2012 

Next, the roadways of Murray County were added. A 90-foot buffer was placed around the roadways to abide by  local siting regulations .

To see a legend of this data layer, click on the Legend Icon found on the bottom left of this map.

Source:  U.S. Code of Federal Regulations, GIS Analysis by Minnesota Department of Agriculture (MDA), Stephan Roos (2018)  

“Prime farmland” is defined, in part, as “...land that has the best combination of physical and chemical characteristics for producing food, feed, forage, fiber, and oilseed crops, and is also available for these uses . . . . It has the soil quality, growing season, and moisture supply needed to economically produce sustained high yields of crops when treated and managed, including water management, according to acceptable farming methods... " (U.S. Code of Federal Regulations, 980, title 7, section 657.5, paragraph (a).

For analysis in this project, the areas considered to be prime farmland were assessed. A map depicting this data layer can be seen at right:

To see a legend of this data layer, click on the Legend Icon found on the bottom left of this map.

Source:  USDA  and  NRCS  , GIS Analysis by  Jessi Wyatt  and  Jake Galzki .

The  crop productivity index  provides a relative ranking of soils based on their potential for intensive crop usage. Values range from 0 to 100, with higher CPI values indicating both greater suitability for agricultural usage and greater likelihood for higher crop yields.

The CPI data for Murray County is alternately expressed in the pie chart below. This graphic illustrates the composition of CPI values across the entirety of Murray County's surface area; the majority of cropland in Murray County has a CPI between 87 - 100 (very productive).

Click on the graphic below to take a closer look at the breakdown of CPI values across Murray County.

To see a legend of this data layer, click on the Legend Icon found on the bottom left of this map.

Through the careful consideration of the aforementioned data layers, we determined the locations in Murray County (shown in blue) which are characterized by the following set of criteria.

• Land not within the boundary of the relevant water features buffer
• Land below the CPI threshold of 55
• Land not on "prime" farmland
• Land not within the 90-foot buffer of Murray County roadways
• Land greater to or equal than 7 acres in size (7 acres is about the size of a 1 MW solar installation)

To see a legend of this data layer, click on the Legend Icon found on the bottom left of this map.

Source:  MDC 2016 

Commonly, energy utility companies will seek out areas contained within a three-mile radius of existing power infrastructure (electric substations and transmission lines). A map depicting a 1, 2, and 3-mile buffer surrounding the existing electric substations in Murray County in addition to a 1-mile buffer surrounding existing transmission lines can be seen in the map at right.

To see a legend of this data layer, click on the Legend Icon found on the bottom left of this map.

Source:  Murray County Business Directory ,  Jean Christoffels  and  Jay Trusty 

Through discussions with Jean Christoffels and Jay Trusty, in addition to consultation with the Murray County business directory, a list of thirty Murray County businesses with potentially high energy usage were identified. High energy using businesses can benefit from utilizing solar through lower electricity costs and federal tax incentives.

Information on the names of these businesses is contained in the GIS content file, but not included on this map.

To see a legend of this data layer, click on the Legend Icon found on the bottom left of this map.

In terms of increasing biodiversity and creating beneficial habitats, native and flowering vegetation, such as milkweed, native forbs, and wildflowers, provides a habitat that attracts and supports native insect pollinators and other beneficial insect predators by providing food resources, refugia, and nesting habitat. Oftentimes,  these solar arrays are located on land previously allocated to agriculture , and solar-native grassland habitat produces a 3-fold increase in pollinator supply and 65% increase in carbon storage compared to pre-solar agricultural land uses. In addition, a number of studies found a correlation between pollinator enhancements and an increase in yields and a decrease in water requirements for certain crops in nearby farms. Specifically, in the Midwest, dominant crops such as soybeans may benefit from the presence of native pollinators. In addition, the flourishing vegetation can even boost energy production from solar panels, as it shades the ground and increases evaporation which cools the solar panels and increases energy output.

The utilization of native forbs and grasses beneath solar panels has been proven to dramatically increase water retention throughout the local ecosystem. The increase in water retention is due to the overall root depths of established forbs and grasses which can reach up to 5 meters.  The deep roots reduce overall water runoff throughout soils for all types of precipitation and drought events . The ability for native forbs and grasses to capture and retain water in various landscapes has been proven through their usage as prairie strips on farms.  These plantings act as buffers between crops that catch and filter water , reducing runoff by 37% when compared to corn and soybean fields.

 In a 2020 study that modeled ecosystem services for native vegetation at solar energy farms , when compared to agriculture and turfgrass establishments beneath solar panels, the water retention of these plantings was 19% greater for agricultural fields, and 9.5% greater than turfgrass.

Soil erosion has become a major issue throughout the entire United States with about a third of topsoil on cropland completely lost from erosion events over time. This loss of topsoil can be traced back to years of consistent plowing for croplands which loosens the soil and makes it prone to erosion. Losing topsoil doesn’t just equate to a loss of the actual soil sediments,  but also represents a loss of organic-rich soil which is full of microorganisms and decayed plant materials that are beneficial to crops  . One solution to the erosion of topsoil is converting and planting native forbs and grasses beneath proposed solar farms to stabilize the soil sediment.  Because of the depth of grassland roots throughout the soil layer, roughly 5m, native grassland will increase the soil stabilization and reduce erosion events .

In a 2020 study that modeled ecosystem services for pollinator friendly habitat at solar energy farms, annual sediment export for native grassland was at .007 tons/ha/year, a major reduction of 95% when compared to cropland and 77% when compared to turfgrass.  Including pollinator friendly habitat beneath solar panels is a proven solution to the loss of topsoil in the United States and can reduce over 9000 tons of sediment from erosion .

Economic development benefits of solar include production taxes that flow to the county, individual land lease benefits, and job opportunities.

Solar Production Credits

• Developers of solar installations which exceed 1MW pay  solar production credits , a form of tax which benefits the local county. 

Landowner Lease Benefits

• Broadly speaking, after a developer has confirmed the viability of a solar project and has undergone construction at the site, landowners begin receiving annual lease payments which range  from $800-$1,200 per acre .

Local Job Opportunities

• As with any development, there are local employment opportunities associated with solar development. The County may consider partnering with local colleges or technical programs to establish job training for in-demand, technical skills in renewable energy and solar development. Jobs in clean energy are among the fastest growing in Minnesota and the nation. More information on careers in this expanding industry can be found at this link provided by the  Clean Energy Resource Teams . A job board containing a list of open positions in the field of renewable energy can be found  here .

An unintuitive but important siting consideration for solar installations is the impact on community character and “viewsheds” - which describe what people see when they look out their window or drive along local roads. For many, the uninterrupted agricultural landscape is considered idyllic, and introduction of new development can be undesirable. Working with the community to ensure screening is considerate of a site design’s impact on community character and viewshed will help ensure that design respects the intention and integrity of the local community. 

Prior to European contact, the land now called Murray County was home to the Sisseton-Wahpeton Oyate. Remnants of traditional settlement by the Sisseton-Wahpeton Oyate people in the area can be experienced today through burial sites and earthworks. Any siting of solar in Murray County should be considerate to the presence of these Indigenous sites, and work to establish a relationship with living relatives to help guide the development process. For more information, contact the Office of the State Archaeologist at  mn.osa@state.mn.us .

Source:  Cropland Data Layer (2018) 

The USDA’s National Agricultural Statistics Service (NASS) Cropland Data Layer (CDL) allows for crop-specific land cover analysis. In any land-use comparisons over time, it is always important to know how the land was being used in the past.

To see a legend of this data layer, click on the Legend Icon found on the bottom left of this map.

Source:  Fall Nitrogen Fertilizer Restrictions 

 Nitrate  is a compound that occurs naturally and also has many human-made sources, including fertilizer. Recent scientific literature indicates potential associations between nitrate and negative human health conditions. The application of fall nitrogen fertilizer is restricted in  Drinking Water Supply Management Areas  (DWSMAs) that have nitrate concentrations at or greater than 5.4 mg/L as provided by the Minnesota Department of Health (MDH). This layer illustrates quarter sections which meet at least one of the three following conditions:

• Deemed as containing  coarse textured soils  by the USDA Natural Resource Conservation Service (NRCS)
•  Karst  is present
• Shallow bedrock is located near the land surface

To see a legend of this data layer, click on the Legend Icon found on the bottom left of this map.

Source:  Minnesota Water Table Aquifer Vulnerability 

This layer displays the susceptibility of groundwater to contamination. The layer includes general categories of the sediment/bedrock types that are associated with landforms which can be used to assign geologic sensitivity ratings to areas. 

To see a legend of this data layer, click on the Legend Icon found on the bottom left of this map.

Source:  Emergency Response Areas  &  Wellhead Protection Areas 

 Wellhead Protection Programs  aim to prevent the contamination of public drinking water via the identification of water supply recharge areas and the management of pollution sources within those areas.

Emergency response areas are those areas determined by the Minnesota Department of Health (MDH) surrounding a public water supply and which completely contain the scientifically calculated  1 year time-of-travel  of contaminant dispersion. Wellhead protection areas are those public water supplies the MDH has determined are susceptible to contamination.

To see a legend of this data layer, click on the Legend Icon found on the bottom left of this map.

Source:  MN DNR Watershed Suite 

The MN DNR Watershed Suite outlines watersheds at nine distinct levels based on the DNR watershed hierarchical system. The layer also showcases specific pour points and flow networks of the watersheds to help with various hydrologic studies.

To see a legend of this data layer, click on the Legend Icon found on the bottom left of this map.

Source:  MN DNR Watershed Suite 

At right we see a map depicting watershed catchments of the Murray County area per the Minnesota DNR.

To see a legend of this data layer, click on the Legend Icon found on the bottom left of this map.

Source:  Environmental Benefits Index: Top Five Percent Areas 

The EBI map identifies areas with the highest potential for storm water runoff and soil erosion in Minnesota. The data layer was created by selecting the top five percent of land with the highest EBI scores of each major watershed. Solar with perennial vegetation for ground cover could be a beneficial economic development option for these areas.

To see a legend of this data layer, click on the Legend Icon found on the bottom left of this map.

Source:  Potentially Undisturbed Land (Virgin Sod)  

This layer depicts the location of lands most likely to contain truly native (virgin) sod. These lands were determined through a rigorous, deductive assessment of tillage and land disturbance history utilizing  USDA/NAIP aerial imagery . This layer may be beneficial for targeted grassland conservation programs, species-specific research, and long-term conservation planning.

To see a legend of this data layer, click on the Legend Icon found on the bottom left of this map.

Source:  MN DNR Native Plant Communities 

This layer represents areas where native plant communities - including state parks and protected areas - are present. These areas are where groups of native plants interact and thrive without the community being altered by human activity or introduced plant/animal species. Strategically placing dual-use solar sites near these areas can serve to expand these native habitats or buffer them from human activity. 

To see a legend of this data layer, click on the Legend Icon found on the bottom left of this map.

Source:  Wildlife Action Network 

The Wildlife Action Network (WAN) is composed of ten GIS layers centered around species in greatest conservation need (SGCN) and the quality of their aquatic and terrestrial habitats. Five layers with sufficient statewide data were combined to rank the areas within the WAN from low to high. Solar-pollinator can be placed to benefit nearby habitats, or to create habitats directly.

To see a legend of this data layer, click on the Legend Icon found on the bottom left of this map.

Source:  Electric Utility Service Areas (April, 2021) 

This map shows the service territory for the local electric utility companies serving Murray County. In most cases, solar will need to be connected to the electrical grid they service, and a power purchase contract will need to be agreed upon.

To see a legend of this data layer, click on the Legend Icon found on the bottom left of this map.