Tag Archive for: Renewable Energy

By Dan Salas and Ben Campbell, University of Illinois Chicago Sustainable Landscapes Program  

Building out the renewable energy capacity needed to make a clean energy transition is no easy task. Siting projects, engineering designs, addressing community interests, and obtaining the resources for construction requires thoughtful planning. Increasingly, one design aspect is gaining more attention: plants.  

As important as any solar panel array, substation, or other “hard” infrastructure, the plants making up the ground covers are critical to site management. Vegetation on renewable energy development (particularly community- and utility-scale solar) has gained attention for its ability to provide added benefits like pollinator and wildlife habitat, soil health, runoff reduction, carbon capturing, and community aesthetics.  

Plant communities, just like other design components, are influenced by many factors. Often underestimated as “the green stuff,” designing, installing, establishing, and maintaining plant communities on large solar arrays can be costly and complex. When done well, it can create an asset to both the project and community. When implemented poorly, it can become a costly and long-term headache for site owners and communities.   

Across the country, communities are asking that solar projects include pollinator habitat in their vegetation planning. As a result, solar developers and site owners have had to face questions like:   

  • What types of plants are included in solar pollinator vegetation?   
  • How do I establish it?   
  • How much will this cost?   
  • If successful, will it result in improvements for local pollinators?   
  • How do we sustain vegetation investments over the duration of solar project lifespan?   

To address these questions, in 2021, The University of Illinois Chicago, U.S. Department of Energy Solar Energy Technologies Office Awardee, began the Pollinator Habitat Aligned with Solar Energy (PHASE) project. This four-year project studies the ecological, economic, and performance impacts of solar pollinator vegetation. Building on this research and industry collaboration, the project also created a suite of decision tools to help site designers and vegetation planners with making informed decisions about plant selection, vegetation management, and addressing project and community goals.  

The four tools developed under the PHASE project have been released and are now free and available for use:   

  • The solar pollinator vegetation implementation manual is an interactive online document to guide users through considerations for vegetation decisions at large- scale solar sites. It also helps identify site goals, pitfalls for implementation, and how to sustain desired benefits over the duration of a project lifespan.  
  • A cost comparison calculator was developed to help project teams consider upfront and long-term costs of plant communities designed for projects. This tool is offered in two formats: one is a simplified online calculator for quick estimates, and the  other is a downloadable Excel tool that allows teams to edit more variables and create a more refined estimate. The outputs of this tool can help inform decisions on construction and operational budgets.  
  • Once target vegetation communities have been identified and budgeted for, the seed selection tool can be used to find species suitable for seed-mixed development. Users can then connect with seed vendors and share outputs to purchase seed material. Project design teams may also use this tool to confirm seed mixes identified for a site and potential substitution species, if needed. Outputs of this tool can be shared with project teams and seed vendors to help seed-mix development in site, design, and vegetation management planning.  
  • Once vegetation is established, the pollinator habitat assessment modules can help verify that vegetation was successfully established and the desired pollinator benefits have resulted from the work completed. A three-tiered series of assessments offers scalability, depending on time and knowledge resources available. These rapid assessments are supplemented by a series of guidance documents that help users decide sampling regimes monitoring needs and reduce monitoring costs.  

Together, these tools offer the renewable energy industry a series of resources that will help improve vegetation management across thousands of acres. While developed with solar pollinator vegetation in mind, these tools are also applicable to other vegetation management programs. Better vegetation management and planning combined with renewable energy creates a brighter future for humans and nature alike.  

About the Solar Energy Technologies Office   

The U.S. Department of Energy Solar Energy Technologies Office accelerates the advancement and deployment of solar technology in support of an equitable transition to a decarbonized economy. Learn more at energy.gov/eere/solar.   

About the University of Illinois Chicago Sustainable Landscapes Program  

The University of Illinois Chicago (UIC) Energy Resources Center is home to the Sustainable Landscapes Program and the Rights-of-Way as Habitat Working Group, which convenes people at the intersection of biodiversity and infrastructure.  

This fact sheet from the U.S. Department of Energy is meant to provide background information for frequently asked questions regarding solar in rural America.

This episode is a conversation between NCAT Energy Program Director Stacie Peterson and Alexis Pascaris, executive director of AgriSolar Consulting.

It is the fifth in a series of AgriSolar Clearinghouse podcasts that are being featured on ATTRA’S Voices from the Field podcast.

Alexis is a consultant and a stakeholder in the AgriSolar Clearinghouse. She and Stacie discuss the social aspects of agrisolar, including the concept of energy as a social matter with technological components, the importance of the cultural landscapes around agrisolar operations, and the “social license” to operate them. Alexis and Stacie also address the stacked benefits of agrisolar itself and agrisolar projects around the country.

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Contact Stacie Peterson at stacieb@ncat.org.

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You can get in touch with NCAT/ATTRA specialists and find access to our trusted, practical sustainable-agriculture publications, webinars, videos, and other resources at ATTRA.NCAT.ORG.

This material is based upon work supported by the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE) under the Solar Energy Technologies Office Award Number DE-EE000937. Legal Disclaimer: The views expressed herein do not necessarily represent the views of the U.S. Department of Energy or the United States Government.

 

The Power of Shade in Agrivoltaics 

“The sun’s energy feeds grazing fodder and crops side-by-side with solar panels. ‘For farmers, it’s a two-income stream,’ said Brad Heins, professor of animal science at the University of Minnesota. That might mean planting crops that thrive in the shade cast by the panels. Or, in Heins’ case, it can mean cooling cows in the panels’ shade rather than resorting to expensive fans in a barn. 

Heins and his colleagues are at the cutting edge of this new field (agrivoltaics), but they aren’t alone. There are hundreds of agrivoltaics projects underway in the US. Some work better than others, and some may wind up not working at all. But the best will lead to a greener and more profitable rural America that embraces renewable energy as an asset.” – The Washington Post 

Agrivoltaic Site Under Construction in Oregon 

“Construction is underway on a $1.5 million project that will allow Oregon State University researchers to further optimize agrivoltaic systems that involve co-developing land for both solar photovoltaic power and agriculture. The five-acre Solar Harvest project is located at Oregon State’s North Willamette Research and Extension Center in Aurora, Oregon, 20 miles south of Portland. It is the result of a partnership between Oregon State and the Oregon Clean Power Cooperative. 

The problem with agrivoltaics research to date, Higgins said, is that it has occurred using solar arrays designed strictly for electricity generation rather than in combination with agricultural uses, such as growing crops or grazing animals. The solar array at the North Willamette Research and Extension Center is designed specifically for agrivoltaics research, with panels that are more spread out and able to rotate to a near vertical position to allow farm equipment to pass through, Higgins said.” – Oregon State University 

Agrivoltaics is Shown to be a “Win-Win” for Food and Energy 

“’With the right investment, innovation and robust collaboration, agrifood systems could become one of the world’s most hopeful solutions to climate change, as well as reduce poverty and provide nourishment for all,’ says Sean de Cleene, head of the Food Systems Initiative at the World Economic Forum (WEF). 

‘The hallmark characteristic of agrivoltaics is the sharing of sunlight between the two energy conversion systems: photovoltaics and photosynthesis,’ says Jordan Macknick, lead energy-water-land analyst at the US National Renewable Energy Laboratory. ‘It essentially mimics what humans have been doing for hundreds of years with agroforestry – think shade-grown coffee – intentionally creating partial shade to create multiple layers of agricultural productivity on the same piece of land.’” – Energy Monitor 

This report seeks to contribute to public understanding of the land use issues related to solar and wind power in the United States. The report draws upon research published during the 10-year period from 2009 to 2019.

The transition to using clean, affordable, and reliable electrical energy is critical for enhancing human opportunities and capabilities. In the United States, many states and localities are engaging in this transition despite the lack of ambitious federal policy support. This research builds on the theoretical framework of the multilevel perspective (MLP) of sociotechnical transitions as well as the concept of energy justice to investigate potential pathways to 100 percent renewable energy (RE) for electricity provision in the U.S. This research seeks to answer the question: what are the technical, policy, and perceptual pathways, barriers, and opportunities for just transition to 100% renewable electricity in the U.S., at a state and local levels? In this dissertation, an analysis of factors contributing to RE transition in communities across the country is developed. Results from this are used to make further analysis and recommendations to research undertaken specifically in the context of Michigan’s Western Upper Peninsula (WUP). This dissertation demonstrates that research on achieving a just energy transition requires transdisciplinary approaches that integrate social sciences, engineering, and natural sciences and multiple ways of knowing from scientists, practitioners, and diverse community perspectives. This research provides tools for decision makers at all levels of government, local stakeholders, citizens, and the academic world in understanding what matters for success in a just transition to 100% RE in the U.S.

This study, performed by a research group that includes AgriSolar Clearinghouse partners Greg-Barron Gafford and Jordan Macknick, describes an integrative approach for the investigation of the co-location of solar photovoltaics and crops, and the potential for co-located agrivoltaic crops in drylands as a solution for the food-energy-water nexus impacts from climate change. 

The research focused on three common agricultural species that represent different adaptive niches for dryland environments: chiltepin pepper, jalapeño, and cherry tomato. The researchers created an agrivoltaic system by planting these species under a PV array—3.3m off the ground at the lowest end and at a tilt of 32°—to capture the physical and biological impacts of this approach. Throughout the average three-month summer growing season, researchers monitored incoming light levels, air temperature and relative humidity continuously using sensors mounted 2.5m above the soil surface, and soil surface temperature and moisture at 5-cm depth. Both the traditional planting area (control) and agrivoltaic system received equal irrigation rates, with two irrigation scenarios—daily irrigation and irrigation every 2ays.

The researchers found that shading from the PV panels can provide multiple additive and synergistic benefits, including reduced plant drought stress, greater food production and reduced PV panel heat stress. The agrivoltaic system conditions impacted every aspect of plant activity, though results and significance varied by species. The total fruit production was twice as great under the PV panels of the agrivoltaic system than in the traditional growing environment

Cumulative CO2 uptake was 65% greater in the agrivoltaic installation than in the traditional growing area. Water use efficiency was also 65% greater, indicating that water loss to transpiration was equal between the treatment areas. The increased productivity in the agrivoltaic system is probably due to an alleviation of multiple stress interactions from heat and atmospheric drought.

Because PV panels are sensitive to temperature, the cooling of panels below daytime temperatures of 30 °C positively impacts their efficiency. In this study, researchers found that the PV panels in a traditional ground-mounted array were significantly warmer during the day and experienced greater within-day variation than those over an agrivoltaic understory. Researchers attribute these lower daytime temperatures in the PV panels in the agrivoltaic system to a greater balance of latent heat energy exchange from plant transpiration relative to sensible heat exchange from radiation from bare soil. Across the core growing season, PV panels in an agrivoltaic system were ~8.9+0.2 °C cooler in daylight hours. This reduction in temperature can lead to an increase in PV system performance. Using the system advisor model (SAM) for a traditional and a colocation PV system in Tucson, AZ, researchers calculated that impact from temperature reductions from the agrivoltaic system would lead to a 3% increase in generation over summer months and a 1% increase in generation annually.

These results show the additive benefits of agrivoltaics, to both crop production and energy production, as well as the impacts to ecosystem services such as local climate regulation, water conservation, and drought resiliency.

The program provides guaranteed loan financing and grant funding to agricultural producers and rural small businesses for renewable energy systems or to make energy efficiency improvements. Agricultural producers may also apply for new energy efficient equipment and new system loans for agricultural production and processing.

This paper explores elements of on-bill financing program design and provides several examples of on-bill products and services. It includes provisions and precautions for equitable programs and describes important financing program design elements.