Tag Archive for: aquavoltaics

Photo courtesy of Far Niente Winery

At Far Niente Winery, respecting the land and all it provides is just second nature. Since 1979, their winemakers have been coaxing award-winning wines out of the grapes grown on their Napa Valley estate, but in 2005 began embracing their role as environmental stewards through their sustainability practices related to farming, winemaking, and renewable energy generation. Located on the Martin Stelling Vineyard in Oakville, Far Niente’s floatovoltaic system is at the forefront of the winery’s commitment to those sustainable practices and ethical winemaking.  

When Far Niente decided to go solar, they faced challenges both unique and common to the agricultural world. Where many businesses may have chosen to place panels on the roof of their buildings, Far Niente’s old stone winery building is on the National Register of Historic Places, making it impossible to do so without violating regulations. Installing ground-mounted panels immediately around the heritage building was not an appealing solution either. After doing the math and realizing they would need to install over 2,000 panels to hit their energy production goal, they were faced with a tough choice: remove established cabernet sauvignon vines or get creative and take a risk. “Taking two acres out of cabernet production really hurts,” says winemaker Greg Allen. “By looking to the pond, it allowed us to maximize how many grape vines we were able to keep and still meet our goal.” These challenges ultimately culminated in the decision to build the world’s first grid-connected floating solar array, despite the lack of real-world success stories of floatovoltaic arrays at the time.  

Developed by Thompson Technology Industries and installed by SPG Solar, the ambitious project went live in April 2008. A total of 1,000 Sharp 208 polysilicon panels were installed over the vineyard’s pond, covering just shy of a full acre. The panels rest atop pontoons anchored to the pond’s banks via marine-grade cabling attached to concrete columns. This setup allows the pontoons to rise and fall with changing water levels throughout the year. Rounding out the vineyard’s solar system are 1,300 ground-mounted panels adjacent to the pond. The system was originally installed with a 500-kilowatt central inverter, but that was replaced after 10 years with 12 SolarEdge string inverters. Together at peak output, the arrays generate roughly 407 kilowatts total with about 177 kilowatts coming from the floatovoltaic system alone. 

Photo courtesy of Far Niente Winery

Unsurprisingly, building such a system comes with a substantial financial commitment. The project’s total cost was $4.2 million upon completion, with an estimated payback period of 12 to 15 years. Fortunately, the net cost for Far Niente was significantly less, thanks to a $2.80/kW self-generation cash rebate from Pacific Gas & Electric, as well as a 30% federal tax incentive and accelerated depreciation tax benefit. The winery worked with Banc of America Leasing and Capital on a seven- year lease as well, which included a buyout option that would allow them to be the sole owners of the system. Far Niente did opt to purchase the array at the end of the seven years, and reports that the system paid for itself at around year 14 of operation.  

With all the energy generated by the system, the winery is able to cover about 80% of its annual energy requirements, but that is far from the only benefit. The floatovoltaic array saves almost a full acre of viable land from being sacrificed for additional ground-mounted panels. Since this part of the vineyard is foundational to the winery’s cabernet sauvignon program, all that preserved space equates to thousands of dollars of bottled cabernet sauvignon revenue saved each year.  

Additionally, there’s reason to believe that the panels’ positioning on top of the pond leads to increased efficiency when compared to the ground-mounted panels. Greg Allen has taken the surface temperature of the panels and found that those on the floating array can measure up to 5 degrees Fahrenheit cooler than their land-based counterparts. Because photoelectric conversion improves in cooler environments, keeping the solar panels at a lower temperature will increase the energy production efficiency when compared to the warmer panels on land.  

A further boon to resource management is the array’s potential to reduce evaporation rates — a crucial win for a vineyard operating in an area seeing increasingly higher temperatures and more frequent drought conditions. While Greg notes that there is no completed study yet, he says, “In my mind, I think that the panels decrease the amount of evaporative loss from the pond.” He adds that it is difficult for the winery to quantify the potential amount of water saved, since there are systems both pulling water from and pushing water to the pond at various times. Currently, the pond serves the winery in several capacities, including as a fire- and frost-protection system, irrigation source, and as the recipient of all process wastewater from the winemaking facility. Three wells intermittently feed the pond, as well. Greg states that there is an ongoing research partnership between the winery and University of California Davis that will hopefully shed light on the shading and water conservation benefits, as well as the ecological impacts of the array.  

When reflecting on the challenges the project presented, Greg says “Interconnection [to the grid] was a big one.” In order to meet their energy production goals, the entire system needed a 500-kilowatt inverter. The winery hit a roadblock with the project when they realized the main service transformer for the winery was only half that size. Far Niente’s utility provider requires that the main service transformer must be able to accommodate 100% of the energy produced by a solar system. “That spawned a massive project of its own,” Greg says, since the winery then had to replace their transformer to match the power rating of the inverter before they could bring the array online.  

As the system approaches 15 years of use, they are noticing more individual panel failures. Greg says that the panels installed in 2007 are no longer commercially available to replace the failed panels, but there is a silver lining. He estimates around five more years of operation with their current set up, and then the winery could begin to look at the possibility of a major system overhaul. Over a decade of research and development has greatly increased the efficiency of today’s panels, providing the possibility of cutting their solar array footprint in half while maintaining the amount of energy produced on-site. “We could regain substantial amounts of vineyards,” he says. Should the winery choose to overhaul their entire system in such a way, the future revenue from the potentially recovered vineyard space could fund the cost of the improved system. 

Photo courtesy of Far Niente Winery

Looking back, Greg says a big challenge has been on the operations and maintenance side of owning the arrays. “Our main job is making and selling wine, and suddenly we’re put in the position of having to – on a daily basis – verify that the system is functioning and then initiate troubleshooting” when it’s needed. He points out that in the beginning, no one at Far Niente was an expert at what essentially became running a small power plant, but they had to develop that expertise in order to keep the system operating. With the possibility of a new system installation on the horizon, Greg speculates that partnering with a third party on a power purchase agreement could be an ideal solution for Far Niente. A power purchase agreement is an arrangement that allows a solar developer to install, operate, and own a system on a customer’s land. The customer is then able to purchase the electricity generated by the system directly from the developer, often at reduced rates. “It means that we would have on-site generation of renewable energy that we use,” he says, “and we would rely on the experts to maintain the system while we focus on growing grapes and making phenomenal wine.”  

No decisions have been made yet as to whether Far Niente will pursue upgrading their system or move towards a power purchase agreement. Regardless of what path the winery will take in the coming years, Greg says they are really pleased with their decision to pursue onsite renewable energy generation and the overall performance of the solar arrays over the years. In particular, the winery’s ownership and staff have enjoyed being pioneers in the field of floatovoltaics. Far Niente’s years of renewable energy generation serve as an excellent example of how solar energy production can support a company’s efforts to implement sustainable measures while existing in harmony with agricultural operations.

New Study Shows Broccoli as Ideal Crop for AgriSolar Farms 

According to a new study by researchers of South Korea’s Chonnam National University, broccoli has shown to be an ideal crop to be grown under solar panels.  

“As per the study, the shade offered by the solar panels helps the broccoli get a deeper shade of green, which makes it look more appealing and it does so without a major loss of crop size or nutritional value. However, financial benefits for farmers producing solar energy are considerably more compared to the income generated by growing broccoli — nearly ten times more. Essentially, farmers are missing out on an opportunity by not having solar panels installed on the field.” – IT Technology 

Cattle Graze Under Solar Panels in Minnesota  

Cattle grazing under solar panels along U.S. Highway 59 in Morris, Minnesota, are under the direction of Bradley Heins, Ph.D., University of Minnesota. The cattle use the panels for shade and shelter, while other aspects of the operation are being studied further, such as water-runoff usage, pollinator habitat, and various potential crops to be grown.  

“Studying both the theoretical and the practical applications of agrivoltaics is James McCall, a researcher in mechanical engineering with the National Renewable Energy Laboratory (NREL). NREL is funded by the U.S. Department of Energy.  

‘To achieve the current administration’s decarbonization goals, we are going to need 10.3 million acres of land (by 2050) to achieve a high decarbonization and electrification scenario,’ said McCall. ‘We see a lot of pushback from local communities who don’t really want these projects on their land or in their community, a solution that has popped up is agrivoltaics.’ 

It’s possible that agrivoltaics could help develop a more pastoral environment for communities, and additional revenue streams for developers and farmers.” – Farm Ranch Guide 

U.S. Army Launches Floating Solar Farm  

Last month, a ribbon cutting took place for a U.S. Army floating solar farm, sited on Big Muddy Lake at Camp Mackall on Fort Bragg, North Carolina.  

“Fort Bragg is the largest military installation by population in the Army, with around 49,000 military personnel, 11,000 civilian employees, and 23,000 family members. The 1.1-megawatt (MW) floating solar farm includes 2 MW/2 megawatt-hour of battery energy storage. 

The floating solar farm is a collaboration between Fort Bragg, utility Duke Energy, and Framingham, Massachusetts-based renewable energy company Ameresco. The U.S. Army’s announcement explains: This utility energy service contract project will provide carbon-free onsite generation, supplement power to the local grid, and provide backup power for Camp Mackall during electricity outages. 

The U.S. Army has a goal of slashing its emissions 50% by 2030 and achieving net zero by 2050. It also wants to proactively consider the security implications of climate change in strategy, planning, acquisition, supply chain, and programming documents and processes.” – Electrek 

GivePower Desalinates Water Overseas Using Aquavoltaics 

“Austin, Texas-based GivePower started by installing solar panels for schools, community centers or other projects in communities in need. But GivePower founder Hayes Bernard realized that people, especially women and girls, would not attend school if they had to walk 8 miles to get water every day. That’s when the idea to include water pumps and desalination came to mind.  

GivePower has seven operational desalination sites in countries like Haiti, Kenya, and Colombia. Four additional solar water farms are expected to become operational by the end of this year. GivePower has different sized desalination sites and setups. The largest one, the Solar Water Farm Max, produces up to 18,500 gallons of water daily — enough to support 35,000 people. It has a solar structure that acts like a roof over the water tanks and the twenty-foot equivalent unit shipping containers that house the desalination technology.” – American Shipper 

Resource Guide for Decommissioning Solar Energy Systems 

A new resource guide on decommissioning solar energy systems, written by AgriSolar Clearinghouse partner Heidi Kolbeck-Urlacher, offers resources for understanding solar project end-of-lifecycle management and recommendations for local governments to consider when drafting decommissioning ordinances. The report is now available through the Center for Rural Affairs here 

“Solar projects are often located in rural areas and can provide numerous benefits to nearby communities, including lease payments to landowners, tax revenue to fund infrastructure and services, and the creation of both permanent and temporary jobs. County officials are typically responsible for enacting siting or zoning standards to help ensure solar development is supported by local residents. This can include planning for the eventual decommissioning of energy projects that have reached the end of their life cycles.”Center for Rural Affairs 

The guide includes examples of decommissioning costs, extending performance periods of solar systems, recycling and disposal of solar panels, sample task lists associated with decommissioning solar systems, and recommendations for plans that define obligations of developers during the decommissioning process.  

Chinese Fishery Deploys 70MW Solar Plant 

“Farms where fish and algae thrive under solar panels might have secured their place in a future powered by renewable energy. Concord New Energy, a Chinese company that specializes in wind and solar power project development and operation, has installed a 70 MW solar plant atop a fishpond in an industrial park in Cangzhou, China’s Hebei region. The hybrid system integrates solar power generation with fishery in a unique way that not only saves land but also produces clean energy. This hybrid system is straightforward: a solar array is installed above the fish pond’s water surface, and the water area beneath the solar array is used for fish and shrimp farming. 

The fishery-solar hybrid system is a type of floating solar farm that has grown in popularity over the years as solar power has evolved to meet the needs of our increasingly climactic times. For example, the United States has just begun construction of the country’s biggest floating solar farm in New Jersey.” – Interesting Engineering 

Valley Irrigation Develops Solar Irrigation Site in Nebraska 

Valley Irrigation has announced the completion of its first North American agrisolar installation in Nebraska through its partnership with Farmers National Company. 

“The installation is located near Davenport, Nebraska, and will provide solar power to a Valley center pivot by offsetting energy consumption used to irrigate the field. Farmers National Company’s landowner client invested in Tier 1 solar panels, which are the highest-quality panels and are also used on major utility-sized installations. They are built to withstand the often-harsh conditions of Nebraska weather, including strong winds and hail.” – Valmont 

“Matt Gunderson is with Farmers National Company and says it helps producers become more sustainable and increase return on investment. “We create some on farm generation not only to power a farm, but how do we tie it back into the grid system to support the electricity needs that are out there? And, along the way with it, sell that electricity back for some excess needs and create some investment opportunities and income generation for producers.” – Brownfield 

This article discusses the mechanism of local micro-climate changes caused by fishery complementary photovoltaic (FPV) power plants to illustrate the impact of FPV power plants in a lake on the environment. It includes details about comprehensive albedo decreases relative to free water surface, water energy change and air vapor pressure deficits. The article also reveals that the FPV panels had a heating effect on the ambient environment, and that the range of this effect was related to water depth.

This report describes a design for an automated, offshore-fish farm, with solar, wind and hydro power as well as a durable, physical structure. The design discussed in the article includes three separate, self-maintaining energies: tidal, wind, and solar. Also included are descriptions of various offshore aquaculture cages intended for deep-water ocean designs.

This article concerns a dynamic model that simulates the main biochemical processes in a milkfish pond that is subject to floating photovoltaic (FPV) cover. The paper includes a model design description that includes details of variable components of the design, including: water temperature, phytoplankton, dissolved oxygen, fish and other variables. Results of the experiment are included, and include: calibration results, ecological effects, and trade-offs between fish and energy production.

This article concerns floating photovoltaic (FPV) systems, also called floatovoltaics, or aquavoltaics, a rapidly growing emerging technology application in which solar photovoltaic (PV) systems are sited directly on water. Along with providing such benefits as reduced evaporation and algae growth, it can lower PV operating temperatures and potentially reduce the costs of solar energy generation. This article provides the first national-level (United States) estimate of FPV technical potential using a combination of filtered, large-scale datasets, site-specific PV generation models, and geospatial analytical tools. The authors quantify FPV co-benefits and siting considerations, such as land conservation, coincidence with high electricity prices, and evaporation rates. Our results demonstrate the potential of FPV to contribute significantly to the U.S. electric sector, even using conservative assumptions.

This thesis investigates using a flexible crystalline silicon-based FPV module backed with foam, which is less expensive than conventional pontoon-based FPV. This novel form of FPV is tested experimentally for operating temperature and performance and is analyzed for water-savings using an evaporation calculation. The results show that the foam-backed FPV had a lower operating temperature than conventional pontoon-based FPV, and thus a 3.5% higher energy output per unit power. A case study of Lake Mead found that if 10% of the lake was covered with foam-backed FPV, there would be enough water conserved and electricity generated to service Las Vegas and Reno combined. At 50% coverage, the foam-backed FPV would provide over 127 TWh of clean solar electricity and 633.22 million m3 of water savings.

This article reports findings of a simulation performed to assess the potential of floating photovoltaic power generation in the tropical Gavião reservoir, located in the Northeast of Brazil. The payback analysis indicates that the investment for construction of the system is fully recovered in 8 years, and that water losses due to evaporation can be reduced by approximately 2.6 x 106 m³/year, enough to supply roughly 50,000 persons.

This article evaluates several scenarios for optimal integration of hybrid renewable energy systems, including floating and floating-tracking PV systems into a representative shrimp farm in Thailand.