Tag Archive for: solar farming

How Will ESG Requirements Influence Agricultural Photovoltaics?

Sunstall’s Sunzaun product installed on a winery.

By Helge Biernath, Sunstall Inc.

I just attended the 2023 Solar Farm Summit, where I presented and spoke to the experts in the industry. One topic never came up: How will ESG (environmental, social, and governance) requirements from companies like Coca-Cola Now and Walmart influence agricultural photovoltaics? ESG requirements from such companies are likely to have a significant impact on agricultural photovoltaics (APV), the practice of integrating solar panels into agricultural lands.

Firstly, these companies have committed to reducing their carbon footprint and promoting sustainable practices in their operations, which will require them to procure renewable energy. APV is a form of renewable energy that can be integrated into agricultural production and help reduce the carbon footprint of these companies. Therefore, the ESG requirements of these companies may drive the adoption of APV by their suppliers and partners. And not only that: they will also require their suppliers to follow similar regimens to reduce the carbon footprint, and they will ask for strategic plans to get there and reports on the success.

Secondly, APV can offer several benefits to farmers, including providing an additional source of income, reducing water evaporation, and improving crop yield. By promoting the adoption of APV, these companies can encourage sustainable agricultural practices and support local communities. Given the ESG requirements, farmers will be asked to support the goal of carbon neutrality. It will be a challenge but also a huge opportunity through solar farming.

Rendering of an APV strawberry field.

Finally, ESG requirements are increasingly becoming a factor in investment decisions, with investors looking for companies that prioritize sustainability and social responsibility. The adoption of APV can enhance the ESG profile of companies in the agriculture sector and help them attract more socially responsible investment.

In summary, the ESG requirements of companies like Coca-Cola and Walmart are likely to drive the adoption of APV in the agriculture sector, promoting sustainable practices, reducing carbon footprint, and improving the ESG profile of companies in the sector.

And the Oscar goes to THE FARMERS! They will be asked to help!

I feel with the solutions we have seen over the last days at the Solar Farm Summit, the agriculture and solar community is ready to support ESG goals.

All photos courtesy of Sunstall, Inc.

VIDEO: How A Shepherd and Solar Developer Are Joining Forces to Grow Sheep, Clean Energy

The National Center for Appropriate Technology’s (NCAT) AgriSolar Clearinghouse today premiered its short film “The Solar Shepherd” during the 2023 Solar Farm Summit in Chicago.

The film showcases a family-owned farm in central Massachusetts that’s raising sheep and solar energy on the same piece of land. AgriSolar or agrivoltaic partnerships are growing across solar-appropriate farmland in the U.S., providing a new revenue source for farmers, clean energy for surrounding communities, and myriad benefits to crops, livestock, and pollinators.

“It’s been a wonderful friendship between the two businesses,” says Solar Shepherd LLC founder Dan Finnegan. “We can’t access enough land to keep our farm sustainable, without this partnership with solar, we wouldn’t have a successful farm, we simply don’t have enough acres to graze.”

Finnegan partnered with SWEB Development Inc. on the 15-acre solar array which provides enough clean energy to power 1,100 homes and has so-far raised 45 lambs to maturity.

“You can have this partnership in a one-acre field, a 15-acre field up to a couple hundred acres,” says Joe Mendelsohn, project developer with SWEB Development Inc.

NCAT’s AgriSolar Clearinghouse is connecting businesses, land managers, and researchers with trusted resources to support the growth of co-located solar and sustainable agriculture.

“Tremendous potential exists in partnerships between farmers and solar developers,” says NCAT Energy Director Stacie Peterson, PhD. “As the demand for solar energy grows, it’s up to us to be good stewards of the finite land resources we have and maximize the benefit to farmers, communities, and the environment.”

AgriSolar News Roundup: NYPA Agrisolar Study Results, Cornell Agrisolar Research, New Solar Panels Increase Crop Yield

NYPA Study Provides Best Practices for Agrivoltaic Systems

“The New York Power Authority (NYPA) announced the release of a new report, Agrivoltaic Leading Practices, that recommends proven and innovative approaches on integrating dual-land use for agriculture and solar energy production. The study determined that a best practice agrivoltaic site ideally involves stakeholder collaboration, community education, policy incentives, site safety practices, and site-individualized crop selection and solar-array design.

Researchers who authored the new report examined how native vegetation, pollinators, low maintenance plants, agricultural crops as well as grazing livestock can coexist on the same parcel of land as a solar energy project.” – The Mountain Eagle

Research Shows Crops and Solar Panels Benefit from Co-Existence

In the threatening trouble of climate change, growing commercial crops on solar farms is a potentially efficient use of agricultural land that can both increase commercial food production and improve solar panel performance and longevity, according to new Cornell research.

“’We now have, for the first time, a physics-based tool to estimate the costs and benefits of co-locating solar panels and commercial agriculture from the perspective of increased power conversion efficiency and solar-panel longevity,’ said lead author Henry Williams, a doctoral student in Cornell Engineering.” – Cornell Chronicle

New Solar Panels Harness Full Light Spectrum and Increase Crop Yields

“According to a new study from the University of California, the blue part of the light spectrum is the most efficient for solar energy production, while the red part is better for plant growth and crop yield. Now, scientists are investigating how harnessing the sun’s complete light spectrum can improve agrivoltaic system’s effectiveness in arid agricultural areas.” – Horti Daily

A Fresh Look at Dual-use Solar in the Pacific Northwest

by Emily Griffith of Renewable NorthWest

Renewable Northwest and a small workgroup are preparing an update to the 2019 report, Dual-Use Solar in the Pacific Northwest: A Way Forward, in response to the changing landscape of agrivoltaics (also referred to as dual-use solar) in the region. This blog will explain the need for a fresh look at dual-use in the Pacific Northwest and describe some of the themes important to the conversation.

Why Do We Need to Revisit Dual-use Solar?

The Biden Administration recently set a goal of reaching 100% carbon-free electricity by 2035. Many states have similar requirements of reaching net-zero GHG emissions. To reach these targets, extensive buildout of solar energy will be a cornerstone of the evolving energy grid. Dual-use solar allows farmers to use their land both as farmland and as a site to generate electricity (and additional income).

In Renewable Northwest’s 2019 report, staff explored the potential and practicality of dual-use solar by looking at advantages and disadvantages, policies, project examples, and best practices. Given the increased attention agrivoltaics has received recently, including federal research investments and policy changes, it’s time to revisit the report. The updated report (to be completed in spring 2023) will explore recent updates in agrivoltaics. Here is what you can expect:

What Has Not Changed?

The conversation around dual-use in the Pacific Northwest is still in early stages. To date, the region still does not have many dual-use projects, but some solar and pollinator projects do exist. For example, Pine Gate Renewables’ Eagle Point Solar is a 13-MW solar and pollinator project located on 41 acres in Medford, Oregon. Previously, the land was used for dairy grazing. Now, the site contains a diverse seed mix of pollinating flowers with over 30 types of native flowers and grasses. Old Sol Apiaries is a business based in southern Oregon that provides bees for honey makers and commercial pollinators. Bees forage on native pollinator plants under Pine Gate’s panels. They also provide bees at other solar-pollinator locations, such as a 73-acre project in Clackamas County, Oregon.

Eagle Point Solar Location

There are a few reasons why dual-use is still not as widely used in this region as it is in others. For instance, there are still policy barriers. In fact, every year there are regular efforts pushing back against solar development by legislators in the Northwest. For example, in Oregon, the Land Conservation and Development Commission issued a rulemaking in 2019 limiting the amount of land to 12 acres that a farmer could use for a solar project located on high-value farmland. However, there was potential for counties to issue ordinances that could increase to 20 acres for dual-use projects. The difficulty with this rulemaking was that it sunsetted after two and a half years, and counties did not have much of a chance to develop an ordinance before the sunset. Additionally, counties in Washington state are continuing to develop ordinances that limit renewable energy development, including potential dual-use projects.

Agrivoltaics continues to be a challenging environment. The idea of agrivoltaics originated in Europe and is just gaining momentum in the U.S. A recent article by Jeff Turrentine at the National Resources Defense Council (NRDC) states that in a number of Asian and European countries, agrivoltaics has gained much more ground. For instance, in Japan, there are 2,000 agrivoltaic installations, whereas in the U.S., there are less than 50 accounted for. The U.S. is not as far along as others for a few reasons:

  • There are significant up-front costs and barriers to entry.
  • Research on large-scale solar with crops and grazing is still considered to be in early stages.
  • There is limited transmission for projects to connect to. Projects most often need to be located near the electricity load (demand).
  • Many farmers are still uneasy about the idea of combining solar and agriculture.

What Has Changed?

While there still are not many dual-use projects in the Northwest, we have seen more interest in the idea of advancing dual-use. New research continues to be published on the advances in dual-use technology and solar-crop compatibility. Some recent studies even suggest that, under the protection of solar panels, certain crops may grow stronger and longer that may otherwise succumb to higher temperatures more readily.

Another interesting Oregon State University study found that there is a symbiotic relationship between solar panels and the crops that grow beneath them. Crops exposed to increased levels of sunlight require more water. With solar panels providing shade and cooler temperatures, less water is lost to evaporation and the plants require less water from irrigation. But perhaps the more interesting finding is that the panels were found to perform better with the crops growing beneath them. The crops beneath the panels contributed to keeping the local environment cooler. With cooler temperatures, the panels operate more efficiently, generating about 10% more electricity than panels installed over gravel.

There are additional efforts and funding being devoted to studying and implementing dual-use projects. Last December, DOE announced $8 million in funding for projects that integrate solar energy production with farming. An energy.gov article states that the funding is intended to reduce barriers to both community and utility-scale solar energy deployment while also maximizing benefits to farmers and local communities. The six states (and the District of Columbia) selected for funding are not located in the Pacific Northwest region. However, the studies will likely produce valuable knowledge that can be integrated here, as well. Some of the topics pertain to socioeconomics, technical aspects, outreach strategies, deployment resources, sustainability, and markets in rural North America.

Additionally, in 2021, the USDA awarded the University of Illinois $10 million to determine the types of crops that are best suited to pair with solar. The research sites include Illinois, Arizona, and Colorado.

With already cost-competitive solar bolstered by the recent passage of the Inflation Reduction Act, solar development is expected to increase dramatically. Hopefully, this means we will see more dual-use projects. And, the increased interest in studying agrivoltaics from the DOE and USDA could perhaps be a sign federal aid is on the way for farmers interested in agrivoltaics. Right now, there is a real need for additional mechanisms and incentives for those interested in pursuing dual-use projects in particular.

How Is the Region Reacting to the Prospect of Dual-use?

While dual-use solar may not be a silverbullet solution to siting solar on farmland, it does offer a tool of flexibility for farmers. This tool can provide additional income that keeps farmers farming and keeps farmland as farmland. The previously mentioned NRDC article states that many people are optimistic about the idea of expanding agrivoltaic facilities with options to sustain farming, potential to bring in new farmers, and stabilize land for crops that could otherwise go to more permanent types of development.

What’s Next?

There are still many other areas of interest that updated report may investigate. For instance, we need to know: Four years later, where are we? Have many projects been implemented since 2019 and how are they doing? Are projects happening practically? What are the dos and don’ts of building a dual-use project? What are the many other studies saying? What are the farmers concerned about?

The U.S. is looking to develop about five times the solar we have to date over the next 10 years, and that solar will require land (at least for its useful life). But new solar buildouts don’t have to result in conflicts. Many think agrivoltaics is a key solution, especially when it comes to avoiding potential conflicts between energy and food production. And with more research and funding being devoted to the idea, dual-use is becoming less of a research question and more of a reality.

If you would like to be notified when the final and updated dual-use report is available, please contact Emily at emily@renewablenw.org

Elevated Solar Trackers Offer a Compatible and High-efficiency Agrisolar Solution for Farmers and Ranchers

Cows on a pasture with elevated Stracker dual-axis solar trackers.
 

By Brigitta Banki and Kate Lundquist, Stracker Solar

Farmers and ranchers all over the United States are increasingly interested in taking part in solar energy initiatives. Agrivoltaics can mean not only cleaner energy, but also savings on operational expenses, as well as the opportunity to develop a secondary income stream by selling the power to utility companies or to offtakers directly through community solar programs.

The available options for agrisolar are greenhouse roof-mounted solar, fixed ground-mounted systems, and elevated solar trackers. Let’s look at the differences, pros, and cons of each type.

Greenhouse Roof-mounted Agrisolar
Fixed solar panels mounted on the roofs of greenhouses are generally the least efficient of all agrivoltaic solar solutions and come with limitations based on the location and roof direction of the structure. The ideal location for solar panels in the U.S. is facing south, with a secondary option of west-facing roof exposure.

In recent years, the popularity of greenhouse roof-mounted solar has grown since those buildings are generally built with a southern exposure. This option has the unexpected drawback of having a markedly negative impact on yields and energy output. One study from the University of Arizona found that when half the greenhouse roof was covered with conventional solar panels, crop output was reduced by 64% and panel productivity was 84% lower.

Fixed Ground-mounted Solar
Low ground-mounted solar panels are a slightly more efficient option. Available in different heights, the panels are installed on rows of metal racking: typical low ground-mounts are at 1 to 3 feet high, while high ground-mounts start around 6 to 7 feet high. A ground-mounted solar system has the advantage of relatively low installation costs, but the intricate support structure can greatly limit access and agricultural use of the land beneath and between the solar panels.

Only certain low-growing crops that are generally hand-cultivated and harvested (such as lettuce, chard, beets, spinach, and tomatoes) are easily grown beneath fixed solar arrays. Access for farm equipment, however, is reduced to the area between rows and only if the installation is designed accordingly. The space around and under a ground-mounted system can be used as grazing area for livestock, as well. However, grazing is only recommended for smaller animals like sheep and goats, in order to avoid damage to the panels or the supporting structure.  

The advantages of fixed ground-mounted systems come from use with low-growing and shade benefitting crops. Benefits are particularly pronounced in regions with hot, dry climates like the American Southwest. Studies have shown that shading from solar panels can maintain and even increase crop yield while reducing water use, an especially welcome option for farms in the areas of the United States where drought is common and water rights are changing.

Elevated Solar Trackers
Elevated tracking solar is the newest and arguably most efficient solution for agrisolar due to the unique tracking design and elevated build. Dual-axis solar trackers have a drive core that moves the arrays along both east-west and north-south axes, maximizing the amount of time the panels receive direct sun exposure. Thanks to the ability to follow the sun’s exact location throughout the day, dual-axis solar trackers provide an increase in energy generation of 50% or more compared to fixed solar power systems with the same number and type of panels.  

Strawberry field with Stracker dual-axis solar trackers.

With maximized solar power production per panel, a small footprint, robust structure, and continued full use of the grounds, pole-mounted dual-axis solar trackers are also the most adaptable solar energy harvesting option for agrivoltaics. Single pole-elevated solar trackers, like Stracker Solar’s elevated dual-axis solar trackers, maintain full use of the land below the solar installation. These high-efficiency trackers feature a 13.6-foot minimum ground clearance with a mounting base of a mere 5 square feet, allowing easy access for every type of farm equipment. Furthermore, since it takes fewer of these high-efficiency solar trackers to generate the desired amount of energy compared to their fixed counterparts, a smaller area is sufficient for the solar installation. The Stracker elevated dual-axis solar trackers deliver up to 70% more energy production compared to fixed solar power systems of the same size. They provide access to solar energy generation while avoiding the financial drawbacks associated with compromising land use or crop yield.

Conclusion
Elevated solar trackers are ideal for agricultural use but all are not created equal. Given the current options for investing in agrisolar, pole-elevated dual-axis solar trackers provide the most flexibility and highest rates of energy generation currently available. These giant mechanical sunflowers maintain full use of the ground underneath the system by accommodating crops and livestock of all types and sizes, including wheat, corn, and cows. Large farm machinery for soil cultivation, crop harvesting, and processing can operate under the panels. Elevated solar trackers make installation on uneven, hilly, or difficult sites a possibility, as well.

Tractor baling hay underneath Stracker tracking system.

However, elevated dual-axis solar trackers vary greatly in design, materials, performance, and durability.

Some dual-axis solar trackers are built using cheaper, and less reliable, aluminum components to reduce costs, while others are built entirely of structural steel. The environmental conditions an installation needs to withstand for 30 or more years while maintaining optimum performance requires a high degree of stability and material strength, both of which are qualities of structural steel.

Material tolerance is another key aspect of solar tracking design that leaves no room for compromise. The build quality of solar trackers is determined by the way different parts of the drive core, as well as the bolts and plates are connected at each step of the way, down to the foundation. With loose connections and weak fittings that could be the result of weaker materials, a tracker could lose its ability to track accurately and perform safely over time.

The most complex, vulnerable, and expensive component of dual-axis solar trackers is the drive core mechanism. Some manufacturers use hydraulic motors and linear actuators, both of which can be the source of a variety of problems. A typical example is hydraulic tank leakage, which makes the tracker stop moving until replaced. These drive systems are often built of galvanized steel and aluminum, though they have plastic components as well, and they don’t meet the structural code requirements of many states. Slew drives are a more durable solution, yet fewer manufacturers use them because they are more expensive and require a higher level of precision to install. Stracker Solar’s elevated solar trackers are built entirely of structural steel and each unit uses two robust electrically driven slew drives for decades of strong performance.

High-quality materials, reliable design, and precision in assembly make a huge difference to the performance and durability of dual-axis solar trackers. But one cannot inspect all the screws and bolts before making a purchase decision. How can one have confidence that the chosen elevated solar tracker will work well in the long run?

That’s where structural warranty comes into the picture.

When calculating return on investment, one needs to consider the accompanying product warranty very carefully. The return on a system with a 10-year warranty is quite different from the return on a system with a 30-year warranty. Since after a 10-year warranty expires, farmers and ranchers will be responsible for the cost of troubleshooting and repairing any structural defects, which can significantly reduce their return over a longer period. Especially when we factor in that manufacturers who only offer a 10-year warranty are likely doing so because they know that their system failure rate beyond 10 years is too high. Stracker Solar is unique in offering a 30-year structural warranty on their elevated dual-axis solar trackers.

Researching available elevated dual-axis solar trackers and other applicable PV systems thoroughly and comparing key features, as well as considering power production data and costs, are very important steps before deciding on an agrivoltaic solution.

As the United States moves towards a zero-carbon future, farms and ranches have the opportunity to become primary sites for community and utility scale solar installations, increasingly supported by funds from the USDA. Elevated solar trackers provide an attractive option for agricultural operations looking towards solar to reduce operating expenses and/or establish a reliable secondary revenue stream.

All photos courtesy of Stracker Solar

AgriSolar News Roundup: Farm to Table Event at Biosphere 2, UAZ Agrisolar Research, German Agrisolar Pilot Project  

Agrisolar Clearinghouse Hosts Farm to Table Event at Biosphere 2  

The AgriSolar Clearinghouse held an AgriSolar Farm to Table event  at Biosphere 2 in Tucson, Arizona, last week, in partnership with the GreenBiz23 conference. Similar to the AgriSolar Clearinghouse Follow the Sun field trips, the AgriSolar Farm to Table events bring members of the agrisolar community together to see, touch, taste, and celebrate the delicious foods grown and grazed at solar farms around the country.

Members of the Agrisolar Clearinghouse, partners and a few others pose for a photo.

The AgriSolar Clearinghouse, along with sponsor Enel North America and partners from Biosphere 2, Connexus Energy, NREL, InSPIRE, Jack’s Solar Garden, and Columbia University, networked with attendees while they enjoyed lunch and refreshments prepared by Chefs Erin, Mateo, and Janos. The menu highlighted foods grown and grazed under solar arrays, including honey, beans, lamb, salad greens, potatoes, and saffron. Discussions ensued amongst attendees while Enel awarded Bare Honey solar-grown honey and the highly coveted agrivoltaic Lego sets.  

Attendees enjoying a solar-grown lunch with live music.

During the lunch, attendees also enjoyed learning about the Biosphere 2’s agrivoltaic project from Dr. Greg Barren-Gafford and graduate students Kai Lepley, Nesrine Rouini, Alyssa Salazar, and Caleb Ortega. Dr. Barren-Gafford provided a background on Biosphere 2, as well as research conducted at the site and its application to agrivoltaics throughout the country. 

Sarah Bendok (right), stands with researcher Nesrine Rouini outside the Biosphere’s agrisolar operation.

Also attending the event was Sarah Bendok, a high-school freshman from Phoenix, Arizonaand founder of Growing Green, a 501(c)(3) nonprofit organization focused on improving agriculture while simultaneously decreasing negative impacts on the environment. Bendok is planning to create an agrivoltaic site at her local community garden and is participating in the AgriSolar Clearinghouse’s peer-to-peer mentoring program under the guidance of Dr. Barron-Gafford and graduate student Nesrine Rouini in pursuit of obtaining the Girl Scout Gold Award.

Attendees arrive at the event outside Biosphere 2.

Thank you to Dr. Barron-Gafford and the Greg Barron-Gafford Research Group; Jesse Puckett; Enel; Rob Davis; Biosphere 2; University of Arizona; Chefs Erin, Mateo, and Janos; the AgriSolar Clearinghouse team; and all the good people that braved the weather to join our agrisolar community in the celebration.  

A happy attendee with some solar-grown refreshments.

More photos from the event can be found here: AgriSolar Farm to Table at Biosphere 2 | Flickr. 

Sign up for the AgriSolar Extra to be sure you know about upcoming Follow the Sun Tour stops.  

University of Arizona Researchers Awarded $1.2 Million to Explore Agrisolar 

“Researchers will test three different watering strategies, ranging from intensive irrigation to almost no water, and use the shadows cast by solar panels to provide benefits to the agricultural process. The most heavily watered plot will closely replicate current agricultural practices and include plants with greater water needs, like tomatoes and varieties of lettuce. The second plot will involve watering to establish growth, but much less thereafter, to reintroduce native grasses. The final plot will require little to no watering and include ‘climate smart’ plants that have grown for hundreds, if not thousands, of years in the region: prickly pear, agave, legumes and others.” – University of Arizona 

Germany’s Vattenfall Invests in 76-Megawatt Agrisolar Project 

“For the first time, Vattenfall will implement this innovative concept of land use on a commercial scale with partners. The aim of the project in Tützpatz is to combine module types on different mounting systems with suitable agricultural uses over an area of 95 ha, and thus gain further practical experience for future commercial projects of this kind. According to current plans, construction at Tützpatz is scheduled to start in early summer 2023.” a– Reve 

Agrivoltaics In Illinois: A Regulatory and Policy Guide

The goal of this policy guide is to summarize both state and local regulations with implications for those wishing to establish agrivoltaic operations in the state of Illinois. The first part of this guide briefly gives a history of agricultural and renewable energy development in Illinois, as well as details agrivoltaic research efforts by the University of Illinois. The guide then covers local-level policies that will have bearing on agrivoltaic development. The final portion of the guide discusses state-level policy that may impact agrivoltaic development, especially in the instance of installing solar panels on agriculturally classified land.

IL-Agrivoltaics-GuideDownload

AgriSolar News Roundup: Agrisolar Pilot Project Results, Vertical PV Research, Translucent Solar Panel Research 

Results of Agrisolar Soybean Pilot Project Revealed by PV Developer 

“French solar developer TSE, in association with Alliance BFC, has unveiled the initial results of a pilot study in France on how solar panels can affect soybean growth. The teams observed solid vegetative growth of the soybeans, with normal flowering, fertilization, and physiological maturation. The six varieties tested presented a diversity of yields: up to 25% difference in yield under the canopy and 19% on the control field.” – PV Magazine 

Oregon Research Studies Use of Vertical PV for Crop Production 

 “There are many different ways to install agrivoltaic arrays. One common method is to raise the array to leave space for farming equipment or livestock to move freely below. Another trending design is to orient the PV arrays vertically, leaving wide open spaces in between the array rows. 

The paper found that an area about the size of Maryland would be needed if agrivoltaics were to meet 20% of U.S. electricity generation. That’s about 13,000 square miles, or 1% of current U.S. farmland. At a global scale, it is estimated that 1% of all farmlands could produce the world’s energy needs if converted to solar PV.” – PV Magazine 

Research Shows Translucent Solar Panels Optimize Crop and Solar Harvest 

“Associate professor Majdi Abou Najm from the Univ. of California, Davis, tested organic solar panels made from translucent material that absorb the blue light to generate electricity, but allow the red light with its longer wavelengths to pass through to the crops below. 

At the UC Davis Agricultural Experiment Station, Abou Najm and his team planted three different plots of processing tomatoes, a common central valley California crop, under a canopy of selective red light, another of selective blue, and a third uncovered plot. 

GNN has reported before on the recent phenomenon of ‘agrivoltaics,’ a practice of growing shade tolerant crops under solar panel arrays. The shade protects the crops from heat stress, while the plants’ transpiration humidifies the air beneath the panels, cooling them down and increasing their electricity output.” – Good News Network 

Agrisolar as Drought Protection  

By Asaf Maman and Avi Elkayam, Trigo Solar 

Declining precipitation levels and the associated reduction in arable land can negatively impact rural communities and pose a threat to food security. While utility-scale solar projects reduce greenhouse gas emissions, they can also encroach on arable lands and reduce the yield of rainfed crops. Wheat, barley, soy, corn, and other grains are cultivated in rainfed fields that are vital to food security. As precipitation levels decline and desertification spreads, arable land and farms that produce these crops are in peril.   

As solar energy is employed in the conversion from fossil fuels to renewable energy, hundreds of thousands of square miles of land will include solar development. According to the National Renewable Energy Laboratory, there will be roughly 22,000 square miles of solar in the U.S. by 2035i. It is important to understand that the actual land for solar development must be adjacent to grid or to power demand centers. The growing competition between farming, suburban development, and solar development highlights the potential for agrivoltaics.  

Agri-PV is a solution to this issue. It can significantly improve the cultivation of staple foods that substantially affect global food security by cracking the code and untying the water-land knot. By increasing the amount of water available for rainfed crops, we can increase the amount of arable land and avail a portion of it for sustainable solar development. 

In a series of field-controlled winter wheat experiments, Trigo has discovered an almost linear correlation between the amount of water supplied to cultivated area and the quantity of stem biomass and nutritional value. Based on these findings, Trigo designed an east-west solar array formation and solar table structure to both collect and regulate rainwater for redistribution into a cultivated row below. By increasing the rain capture area from both structures, enclosing, and effectively directing the rain, we managed to control the amount of water and increase it, countering the effects of declining precipitation over years.  

North-south solar array over winter wheat. Photo: Trigo Solar 

Design schematic. Source: Trigo Solar 

This design is focused on economic and efficient deployment of solar arrays that improve rain collection and redistribute water to boost crops growth, counter drought effects, and revive agricultural operations.  

Rainwater catchment design schedmatic. Source: Trigo Solar 

Benefits to this design include:  

  1. Maintaining the same yields from smaller cultivated surface area requires more limited farming operations and lower expenses, which can increase farm profitability. 
  1. Capturing more water and channeling it smartly reduces the risk of drought and the associated annual volatility and provides the farm with a drought shield. 
  1. Increased ground wetness, root growth, and wind shield from the solar rows reduces the erosion and carry away of the upper soil layer, which create irreversible damage to farms. 
  1. Preserved land under the Trigo structure can be used for future land reserve and land rotation. 
  1. The steady income from solar power generation can support farm economics and mitigate farming financial risks. 
  1. The availability of cheap, local, green power can further support many of the farm operations expected to undergo electrification in the coming decade. 
  1. The existence of a water-distribution and cheap-power system changes the economics of farming, potentially allowing the cultivation of second seasonal crop during the dry season.  

These benefits have the potential to create more win-win opportunities for effective cooperation between the agricultural and sustainable energy sectors. 

Trigo will continue its experiments to validate the benefits for major U.S. staple crops at U.S. farms to share the knowledge and promote sustainable mass Agri-PV development.  

AgriSolar News Roundup: Win for America’s Farmers, 5 Signs of Agrisolar Revolution, Agrisolar Pumps in India, Harvesting Light in Agrisolar, Massachusetts Solar Incentives 

Win for America’s Farmers: Harvesting Solar Energy 

“America’s solar industry has boomed in recent years, and is slated for a big boost from the Democrats’ recently passed climate bill. Yet solar still only accounts for about 3 percent of electricity flowing into America’s grid—less than one-seventh the share from coal. If we want to phase out fossil fuels and accommodate an electric vehicle revolution, the sun’s contribution has to rise dramatically—and fast. But where to put all the panles?

The best places for solar installations, according to a 2019 study from the University of Utah and Oregon State, tend to be the areas where we already grow our food. That’s because, just like sun-loving tomato plants that fare poorly when the mercury creeps north of 85 °F, photovoltaic (PV) panels lose their efficiency at higher temperatures. But that doesn’t mean we have to starve ourselves to keep lights on and cars humming. By elevating solar panels far enough above the ground so people, plants, and animals can operate underneath, we can “essentially harvest the sun twice,” says University of Arizona researcher Greg Barron-Gafford. Enough sunlight to grow crops gets past the panels, which also act as a shield against extreme heat, drought, and storms.” – Mother Jones  

5 Signs the US Agrisolar Revolution has Begun  

“An upswell of opposition to large-scale solar power plants on farms took shape in the U.S. last spring, partly fueled by conspiracy theories about climate change. Nevertheless, farmland is attractive to solar developers. Now they have a new support system on their side, in the form of agrivoltaics.” – Triplepundit.com  

Solar Energy Corporation of India Issues Tender to Install Agrisolar Pumps 

“New Delhi: The Solar Energy Corporation of India (SECI) on Monday issued a tender for setting up agricultural solar pumps in selected states pan-India under component-B of the PM-KUSUM scheme of the renewable energy ministry.  

‘Individual farmers will be supported to install standalone solar agriculture pumps of capacity up to 7.5 HP for replacement of existing diesel agriculture pumps and irrigation systems in off-grid areas, where grid supply is not available. Installation of new pumps will be permitted under this scheme except in dark zone areas,’ said the SECI tender document.” – Energyworld.com 

UC Davis Study Shows Harvesting Various Light Spectra Benefits Agrisolar  

“Scientists from the University of California, Davis, are investigating how to better harvest the sun — and its optimal light spectrum — to make agrivoltaic systems more efficient in arid agricultural regions like California. 

Their study, published in Earth’s Future, a journal of the American Geophysical Union, found that the red part of the light spectrum is more efficient for growing plants, while the blue part of the spectrum is better used for solar production.” UCDavis.com 

Massachusetts Sees Increase in Agrisolar Incentives 

“A Massachusetts incentive program for projects that blend solar energy and agricultural production shows signs of finally gaining momentum after a slow rollout that has at times frustrated solar developers and farmers alike. 

In 2018, Massachusetts became the first state to offer financial incentives for “dual-use” or “agrivoltaic” solar projects built above active agricultural land. Since the launch, however, just three projects have gotten up and running. Another eight have qualified for the incentive but not yet been built.” – Energynews.com