Tag Archive for: Agrivoltaics

Massachusetts Farm Partners with BlueWave in Dual-Use Solar

The Knowlton Farm, a Massachusetts agrisolar operation, has recently partnered with BlueWave Solar to expand agrisolar operations on the farm in Grafton, according to an article by The New York Times.  

Owner Paul Knowlton stated that the farm typically produces a variety of vegetables, dairy products, and hay, but also produces solar energy. He said that solar was already part of the farming operations, providing electricity for both his barn and home, but through this partnership with BlueWave, the farm will include a parcel of land where solar panels will share space with crops, known as dual-use solar, according to the report. 

The dual-use solar operation includes adjusting the heights of solar panels to allow farm operations, including workers, equipment, and grazing animals, to operate underneath them. Spacing and angles of the solar panels are adjusted to benefit crops growing below them—shielding them from the elements, including intense heat. Some of the panels will have cattle grazing beneath them while others will grow butternut squash and lettuce. 

The AgriSolar Clearinghouse will be touring the Knowlton Farm on August 10, 2022, as part of the Follow the Sun Tour. The tour is a series of hands-on field trips to see firsthand the benefits of co-locating sustainable agriculture and solar energy. Other locations on the tour include the Massachusetts Amherst South Deerfield research site and the Million Little Sunbeams family farm. 

Pollinator-Friendly Solar in Plains, Georgia: A former U.S. president’s clean energy legacy

Pollinator-Friendly Solar in Plains, Georgia: A former U.S. president’s clean energy legacy

By Briana Kerber

Sunset with Gaillardia and Solar Array. Photo: Jill Stuckey

With clean energy developments continuing to ramp up across the United States, more attention is being paid toward how best to develop these projects at the pace and scale that the climate crisis requires while also ensuring that we are taking care of the sites and communities that host those projects.    That’s where a national project from the National Renewable Energy Laboratory (NREL), Great Plains Institute (GPI), Fresh Energy, and the University of Minnesota comes in. Funded by the U.S. Department of Energy’s (DOE) Solar Energy Technology Office, the Photovoltaic Stormwater Management Research and Testing (PV-SMaRT) project is using five existing ground-mounted photovoltaic (PV) solar sites across the United States to study stormwater infiltration and runoff at solar farms.

Together, the five sites represent a range of slopes, soil types, geographical locations, and PV configurations that will help solar developers and owners, utility companies, communities, and clean energy and climate advocates better understand how best to support solar projects and the host communities in which they are built, lowering the costs of clean energy development while ensuring protection of the host community’s surface and ground waters.

An early introduction to clean energy advocacy

Former President Jimmy Carter was an early advocate for clean energy development across the United States, from the West Wing of the White House to pockets of rural America, like his hometown of Plains, Georgia. Today, seven acres of a 25-acre parcel of former President Carter’s land, where peanuts and soybeans used to grow, is now home to a solar farm that can power more than half of Plains, a city of around 640 people. Situated in the middle of what is now a neighborhood, the project began when solar developer SolAmerica Energy approached the former President’s family about the possibility of installing panels on the land. That solar site now feeds into Georgia Power’s grid and is helping restore pollinator habitat, a well-known priority for former First Lady Rosalynn Carter, who helped create the Rosalynn Carter Butterfly Trail.

A flat site with sandy clay soil, Carter Farms hosts 3,852 solar panels to provide 1.3 megawatts of electricity to the Plains community via tracking, one-in-portrait arrays. As shown in Figure 1, the site is testing three separate seed mixes to monitor how the various ground cover intersects with stormwater management:

  1. Crabgrass, annual ryegrass, and panicum
  2. Low-diversity pollinator mix (seven species): Indian blanketflower, common sensitive-plant, butterfly milkweed, southern elephant’s-foot, finged bluestar, rayless sunflower, southern beardtongue
  3. High-diversity pollinator mix (18 species): Indian blanketflower, partridge pea, blackeyed Susan, yarrow, lanceleaf coreopsis, southern elephant’s-foot, mistflower, and others

Figure 1. A map of the seed mixes on six different plots at the Carter Farms solar site in Plains, Georgia. Graphict: Aaron Hanson

Since the site was first built to accommodate the solar industry standard of planting some sort of grass underneath the panels, which requires more frequent mowing, the PV-SMaRT team and local partners are still monitoring the six different plots at the Carter Farms site to determine the full impact of the pollinator-friendly seed mixes. Bodie Pennisi, a professor of horticulture with the University of Georgia, reports that, so far, the dominant grasses in the control areas have been crabgrass, annual ryegrass, and panicum. “2022 is the year when we expect the strongest bloom from the perennial species, and we are really excited to see what pollinators and other beneficial insects come to the flowers.” Although the site plots are still being monitored, that hasn’t stopped researchers and other project participants from drawing initial conclusions and getting excited about the many benefits the pollinator mixes will bring for biodiversity, the climate, and SolAmerica’s site management costs. Figure 3 shows a morning bloom of black-eyed susans from the high-diversity pollinator mix.

Figure 2. Blackeyed Susan flowers blooming at sunrise at the Carter Farms solar site. Photo: Jill Stuckey

Designing solar sites with extreme weather in mind

As discussed in Fresh Energy’s first PV-SMaRT case study on Connexus Energy’s Minnesota site, when engineers and researchers sit down to plan out or conduct analyses on clean energy developments like solar farms, they often utilize something called a design storm to test how well the site will hold up against an extreme weather event like a flood. A design storm is essentially a test flood event of a certain magnitude—the higher the magnitude, the more intense the test storm for modelling and analysis purposes. These tests help researchers and engineers monitor rainfall and soil moisture as well as determine how fast excess water soaks into the ground during extreme storms. Figure 3 shows the water monitoring equipment at the site.

Figure 3. Water monitoring equipment sits at the west end of the Carter Farms solar site. Photo: Jake Galzki

Jake Galzki, a University of Minnesota researcher who is part of the modeling team for the PV-SMaRT project, says, “The Carter Farms site has a deeper profile than other sites we’ve studied – it’s a meter and a half to the nearest restrictive layer. That means the rooting depth for ground cover is deeper than other sites. And the soil at this site is essentially a 1:1 sandy clay, meaning it is comprised of 50 percent clay and 50 percent sand.” He adds, “In terms of measuring the runoff at Carter Farms against the other four project sites, the runoff here is moderate despite being the wettest site we’ve studied. We noted good infiltration capacity when testing the 100-year design storm, but we also did see some runoff due to the high clay content of the soil, which is very typical during such extreme events.”

Aaron Hanson, energy program specialist at the University of Minnesota’s Institute on the Environment, says: “It’s great that we have such diversity among our research sites. The climate and soil conditions in southern Georgia are quite different from what we are used to in Minnesota. The ‘growing season’ is actually reversed. Rather than having snow cover in the winter, they have a dormant period during the heat of the summer. This diversity of research site conditions will ultimately help our model to be applicable for solar developments across the country.”

Craig Kvien, one member of the Georgia-based site management crew, is an agricultural specialist whose expertise with innovative solar and agricultural projects runs decades deep. Craig says that the process for tending to the plots has come with its challenges, namely weeds. “We’ve got a team of people who’ve been sampling and documenting the plant and insect species that are out there over time, including the ones we anticipated, and those we did not,” Craig says with a chuckle. He adds, “Part of the process for ensuring the pollinator mixes can thrive requires a good amount of effort to beat down the weeds that also want to grow.”

But Craig isn’t daunted by what he calls a “standard mix of hard-to-get-rid-of weeds, which includes briars.” When asked what it is about the project that excites him the most, he doesn’t hesitate to remark on the beauty of a multi-use property: “There are lots of options. It seems silly not to do something useful with the land underneath the solar panels, particularly if you can make a difference somehow, either by enhancing the pollinator species in the area—or making or saving an extra buck.”

Science reflected in the practice

Brian Ross, vice president of renewable energy at Great Plains Institute and project lead for PV-SMaRT, says, “This site in Georgia helps bring both scientific validity to the modeling and runoff coefficients, adding diversity of soil types, hydrology, and land use, but also to develop regulatory, permitting, and project best practices that flow from the science.” He adds, “Georgia regulators have been participating in these discussions and helping ensure that the science is ultimately reflected in the practice.”

John Buffington, vice president of SolAmerica Energy, says the pollinator piece was a key consideration for the company. “SolAmerica was originally motivated by the opportunity to contribute to the restoration of pollinator habitats,” John says. “We think supporting these initiatives is the right thing to do and gives us an opportunity to be a more engaged member of the communities in which our solar developments are located. Later, we were excited to hear about the stormwater and cost-management aspects of pollinator-friendly solar.”

According to John and the SolAmerica team, pollinator-friendly solar has the potential to change the whole solar industry. “We could have done a pollinator project and just been quiet about it,” he admits. “But that wasn’t the intent, because we were trying to inspire the industry, and the Carter site was a great vehicle for that. These pollinator-friendly and stormwater supporting practices help contribute to better management of a site by reducing the amount of our budget that goes to mowing and other maintenance. So, beyond the pollinator restoration aspect, there are clear business benefits to doing this with a solar site.”

Ongoing stakeholder feedback

Like the other PV-SMaRT sites, data and observations from the Carter Farms site now serve as a benchmark as the PV-SMaRT research team continues to gather insight about each of the five project sites across the country. Overall, ongoing findings at the Carter Farms site further validate the project’s recommended best practices for solar developments and stormwater management: We can help lower the soft cost of clean energy development and of ongoing maintenance, protect the host community’s surface and ground waters, create needed habitat, and sequester carbon in the soil, all while helping craft a truly sustainable clean energy future that will benefit everyone for generations to come—just as the Carters have long worked towards.

Throughout 2022, experts and stakeholders will be reconvening in this process to continue to examine and provide feedback on this foundational research. Read the first PV-SMaRT case study on Connexus Energy’s Minnesota site, get the latest updates from Great Plains Institute, and stay tuned for the third and final PV-SMaRT case study from Fresh Energy and partners.

A version of this article was originally published via Fresh Energy. Read it here.

US Solar Partners with T-Mobile on Minnesota Solar Gardens

US Solar and T-Mobile have partnered on 14 Solar Community Gardens in Minnesota. T-Mobile’s sunscription to US Solar’s Community Solar Garden means the company will benefit from local solar without upfront costs and equipment. The energy-cost savings will apply to seven Minnesota counties.  

Erica Forsman, Vice President of Origination at US Solar, stated, “We’re focused on providing solutions to our commercial partners that make it simple and beneficial to support local clean energy. We are excited to partner with T-Mobile and provide a renewable energy solution to support their industry-leading sustainability goals in Minnesota and across the nation,” according to Businesswire. 

US Solar also partners with Excel Energy, not only operate over 120MW of renewable energy to their grid but has implemented AgriSolar operations by planting pollinator-friendly vegetation on those sites. This pollinator-friendly vegetation on solar sites reduces stormwater runoff, enhances soil regeneration, and increases air quality in surrounding communities.   

Three of the Minnesota Community Solar Gardens began operation in late 2021, and the other 11 are in various stages of development and construction. In early 2021, T-Mobile became the first telecom to achieve their RE100 commitment to source 100% of their electric usage from renewable energy.     

Learn more here. 

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Agrivoltaic Systems Enhance Farmers’ Profits through Broccoli Visual Quality and Electricity Production without Dramatic Changes in Yield, Antioxidant Capacity, and Glucosinolates

This paper shows that agrivoltaic systems allow us to reach sustainable food and electricity goals with high land-use efficiency. The study shows the yield, antioxidant capacity, and secondary metabolite of broccoli and electricity production were analyzed under an agrivoltaic system over three cultivation periods. The study also reports that agrivoltaic with additional shading treatment produced greener broccoli with a higher level of consumer preference than open-field grown ones.

 



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AgriSolar News Roundup: Solar Leasing Guidebook and Workshops, Maryland Solar Bills, Australian AgriSolar

American Farmland Trust Announces Guidebook and Workshops for Solar Leasing 

American Farmland Trust, a stakeholder in the AgriSolar Clearinghouse, has announced they will offer virtual and in-person workshops designed to help ranchland and farmland owners understand the emerging solar-development field. 

“Solar energy development is accelerating rapidly in our region, and what we’re seeing is that farmland and rangeland owners are on the frontlines of this trend,” says Addie Candib, AFT Pacific Northwest Regional Director. “Many communities are wrestling with the question of whether – and where – solar should be built, but at some point, it will be up to the individual landowner to decide what’s in the long-term best interests for their business and their families. That’s what this project is about – helping farmers and ranchers to make informed decisions about the future of their land.” – American Farmland Trust 

Pair of Community Solar Bills Passes in Maryland 

“The Maryland legislature has taken steps towards strengthening its ongoing community solar pilot program, passing a pair of bills targeted at increasing the amount of eligible projects, and increasing the incentive for such projects to be developed. HB 1039 and HB 440 create tax incentives for the development of agrivoltaic community solar projects which serve low- and moderate-income customers on rooftops, brownfields, landfills, and clean fills, as well as increasing maximum project capacity to 5 MW. The bills both build on regulatory action from 2021, which expanded the program to allow community solar to power the equivalent of an additional 6,840 Maryland homes, while also allowing community solar projects to be built on clean-fill construction sites, transforming previously unusable industrial locations into clean solar energy generation sites.” – PV Magazine 

Australian Solar Park will Host Crops in New AgriSolar Program 

“Italy’s Enel will launch an experimental agrivoltaics program at its 34 MW Cohuna Solar Farm in the Australian state of Victoria to help formulate a ‘best practices’ template for utility-scale solar PV sites in other countries. Enel Green Power Australia, a subsidiary of Italian energy giant Enel, will explore how to combine solar PV generation and agricultural production in a new research program to be undertaken at its Cohuna Solar Farm in northern Victoria. Much of the land near the Cohuna Solar Farm is home to sheep grazing operations. While ‘solar grazing’ is proving to be a popular form of land co-use for large-scale solar, other forms of agrivoltaics are emerging that support horticulture, viticulture, aquaculture and even cropping activities.” – PV Magazine 

AgriSolar News Roundup: Pastureland, Australian Grazing Quality, Regenerative Energy

Pastureland: Solar Panels and Sheep 

“Grazing by sheep and other livestock joins other dual uses: planting groundcover to benefit pollinators, growing marketable plants such as cherry tomatoes and lavender under the panels, installing beehives, and maximizing soil health practices to improve the land for later ag use. The use of solar sites for livestock grazing is still in its infancy, but flocks of sheep are already grazing contentedly under and around glass panels in Pennsylvania, Virginia, Maryland, and New York. By welcoming the grazers, solar operators save money on land maintenance. After the cost of leasing the land, vegetation management is often their top expense.” – Bay Journal 

Solar Panels Increase Australian Grazing Quality During Drought 

“Two agrivoltaic installations in New South Wales, Australia, are being credited with increasing the quantity and quality of fleece in sheep grazing at the facilities during a drought. Research has indicated that the partial shade offered by solar panels creates a microclimate that reduces evaporation and significantly boosts the production of vegetation in arid climates. Researchers found that areas that were partially or fully covered by solar panels increased their biomass production by 90%.” – PV Magazine 

Silicon Ranch’s Regenerative Energy Program  

“Silicon Ranch founded a branch of its company dedicated to regenerative land management practices nearly four years ago and has found that a forward-looking, natural approach to solar project planning is proving fruitful in the long term. To address degraded soils and topsoil regeneration, Regenerative Energy gathers a seed mix of grasses native to that respective region and re-seeds the site. Given the length of the solar development process, seeds are ideally sown at least one year ahead of construction. Newly rooted plants will reintroduce stability to that soil.” – Solar Power World 

Tasting the Fruits and Vegetables Grown Under Solar Panels

By: Mariah Rogers, Graduate Student, University of Arizona

Do plants taste different under solar panels? Do they taste better? At the Biosphere 2 Agrivoltaics Learning Lab, we studied just that.

Why Should We Use Agrivoltaics?

Agrivoltaics—the production of agriculture and solar photovoltaic energy on the same parcel of land—is gaining attention as farmers are facing new struggles amid the climate crisis. With agrivoltaics, farmers can reduce water consumption, produce renewable energy, and continue to cultivate their land. However, there is skepticism toward growing crops under solar panels, as farmers may have to change the types of plants that are more shade tolerant.

The Biosphere 2 Agrivoltaics Learning Lab

At the Biosphere 2 Agrivoltaics Learning Lab (B2AVSLL), we study the microclimate—that localized environment under the solar panels— and how plant adaptations occur in the shade of the agrivoltaic system. Some of the adaptations that plants make in the agrivoltaic microclimates include differences in yield, changes to plant morphology (leaf size, fruit shape and color), and alterations in metabolites. These adaptations may cause differences in how people perceive these crops. To study these differences, we grow a slew of different crops underneath solar panels.

We grow tomatoes, basil, potatoes, beans, squash, and lavender, just to name a few. While some of the plants grown at B2AVSLL are heat tolerant, crops grown in this region of the U.S. still require a lot of water. With agrivoltaics, we can reduce water consumption and still have a good yield. So, it is in our best interest to figure out if they would be successful both for the environment and in the market.

The Study Goals

To understand how these crops would do in the market, we conducted a consumer sensory study at the University of Arizona. The three goals of the study were to: (1) to understand if people perceived a difference between agrivoltaic-grown crops vs. crops grown in full sunlight (control); (2) determine if people preferred agrivoltaic-grown crops compared to control; and (3) discover if people were willing to pay more for crops grown in agrivoltaic conditions.

A total of 105 people participated in the study. Panelists were subjected to different conditions and samples, based on the site and the day they were tasting samples. Tomato and basil, potato and bean, and potato and squash were tasted by panelists.

Does Agrivoltaics Change the Flavor of Plants?

To understand if there was a difference between agrivoltaic- and control-grown samples, we used a triangle test where participants were given three samples with a random three-digit code; two of the samples were the same and one was different. We then asked the participants to pick which sample was the “odd one out.”

So, did agrivoltaics change the flavor of the crops? Yes and no. Tomato, bean, and squash samples (all fruits) were perceived as different by tasters. Basil and potato samples were not perceived as significantly different by tasters.

Does Agrivoltaics Make Plants Taste Better?

To understand if there was a preference between samples from the two growth conditions, we then conducted a paired preference test. We gave tasters two samples with random three-digit codes and asked if they preferred one sample more than another, or if they preferred neither sample.

Unsurprisingly, the results were mixed. People significantly preferred beans grown in the control setting over those grown in agrivoltaics. In addition, agrivoltaic-grown basil, potato, and squash samples were preferred by tasters.

Are People Willing to Pay More for Agrivoltaic-grown Produce?

After the triangle and preference tests, we asked participants if they would be willing to pay more or less for their favorite samples. Overall, we found that participants were willing to pay the same or more for all samples after they knew that their favorite samples were grown in agrivoltaic systems.

What Does This Mean for Farmers and Investors?

Because consumers can’t tell a significant difference in vegetable samples, and they preferred basil, potato, and squash, it may be in farmers’ best interest to grow these crops, especially in the desert. By marketing the produce as grown under solar arrays, and educating consumers about agrivoltaics, farmers may be able to sell their produce for slightly more at farmers markets.

What Does This Mean for You as a Consumers?

Buying for foods that are grown using agrivoltaics means supporting solar energy generation through purchasing fruits or vegetables. If you already go to the farmers market to buy fruits and vegetables, you may want to consider buying agrivoltaic-grown produce. If you want something that tastes like what you already buy from the farmers market, then you may want to buy vegetables. If you are looking for a different tasting product, you may want to buy fruits grown under agrivoltaics. You can be the judge whether you prefer one growth condition over another.

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Tunable Photovoltaics: Adapting Solar Cell Technologies to Versatile Applications

This report discusses the main principles of different tuning approaches in customizable photovoltaic designs and provides an overview of relevant concepts of tunable SC technologies. The report provides a systematic analysis addressing photovoltaic materials, electrode layers, optical structures, substrates and encapsulates. Also included is a summary of integrations of cutting-edge tunable PV adapted to versatile applications, current challenges, and insightful perspectives into potential future opportunities for tunable PV systems.

Advanced-Energy-Materials-2022-Meddeb-Tunable-Photovoltaics-Adapting-Solar-Cell-Technologies-to-VersatileDownload

Australian Agrisolar Shows Grazing Sheep Under Solar Panels May Enhance Wool Production

Sheep grazing under solar panels in Australia’s South Wales has resulted in an increase in the quantity and quality of wool, says a report from ABC Rural. Local graziers are calling it a “win-win” situation. 

Grazier Graeme Ostini says his farm is now cutting “an amazing amount of wool.” And due to condensation from the solar panels, the sheep are able to graze almost entirely through the (Australian) drought years, says the report.  

Former grazier and farmer Tom Warren leases a portion of his land to a solar farm on which250 sheep graze under solar panels. Since leasing his land, his income has increased and the carrying capacity of his land has increased nearly 25%.  

“It’ll be because of the conditions the sheep are living in. It’s relatively clean, without burrs, without dust. There’s very, very little contamination of the wool and they’re protected from the sun as well,” said Warren. 

Madeline Taylor, energy policy and landholder rights researcher, said, “We’re starting to get a really good database of studies showing how the co-location of agriculture and photovoltaics can be done successfully. We’ve seen that it works really well for grazing. Now, believe it or not, cropping can also really work very well alongside solar energy,” according to ABC Rural. 

AgriSolar News Roundup: Australian Agrisolar, Floating Solar Panels, Biodiversity Impact Study

Agrisolar Will Continue on Former Australian Coal Plant Site

“The national CEFC and Octopus Australia said earlier this month that their joint venture (JV) is developing a 1.5GW renewable energy hub to help replace Victoria’s soon-to-retire Yallourn coal power plant. The pair said they will jointly develop Blind Creek Solar and Battery Project in Bungendore, New South Wales. The goal of Blind Creek is that it will co-locate renewable energy generation with regenerative agriculture and carbon sequestration. Sheep grazing will continue to take place on the site.”  – Energy Storage News

Clean Energy Could see Floating Solar Panels as the Next Big Thing

“Floating solar is still a new way of approaching solar power compared to the land-based panels we’re used to, but it appears to have a lot of potential in areas where land for solar farms is scarce or there is simply an abundance of water. The more solar we install, on the ground, on rooftops or even on the seas, the less we’ll be reliant on fossil fuels.” Popular Science

New England PV Plant Will Study Solar Impact on Biodiversity

“The University of New England’s own 3.2MW solar farm is proving its worth in more ways than one, not only as an independent renewable energy source for the university, but also as the setting of a pilot study to better understand the impact of large-scale solar on biodiversity. The study aims to learn whether solar plants are useful habitats for wildlife and if simple land management strategies during construction could better cater to native species.” – PV Magazine