In the quest to transition away from fossil fuels, the global interest in solar energy has witnessed a significant surge. Notably, countries in Europe, grappling with harsh winters, are exploring innovative ways to harness solar energy. One groundbreaking approach gaining traction is the integration of solar panels into agricultural landscapes, a concept known as agrivoltaics. The marriage of agriculture and solar energy on the same land opens up new possibilities for sustainable, dual-purpose land use.
A pivotal player in this evolving field is Sunstall, a California-based company that has introduced a revolutionary vertical solar panel named Sunzaun. This innovation allows for the deployment of solar panels in existing fields and arable lands without compromising their primary agricultural function. Sunzaun utilizes bifacial solar modules, and its unique design stands as a boundary wall within the agricultural landscape, maximizing land efficiency.
Traditionally, agrivoltaics has involved elevated platforms for mounting solar panels, creating shaded areas underneath where crops can thrive. This dual-use strategy offers benefits such as efficient land utilization, clean energy production, and potential water savings due to reduced evaporation. However, the elevated platform approach comes with increased installation costs.
Sunzaun breaks away from this norm by simplifying the installation process. The vertical solar panels can be seamlessly integrated wherever convenient, without the need for elevated platforms. Moreover, these panels can be installed with a slope of up to 15 degrees, providing flexibility in deployment. Sunzaun’s versatility extends beyond agricultural fields, as the panels can serve as city infrastructure, lining highways, railroads, and even acting as residential or public fences.
A notable feature of Sunzaun’s design lies in the use of bifacial solar modules, eliminating the necessity for a south-facing configuration. Conventionally, solar panels are oriented toward true south in the northern hemisphere to maximize direct sunlight exposure. Sunzaun’s vertical panels, however, can face east-west and still achieve optimal energy generation, showcasing the adaptability of bifacial technology.
Recent studies indicate that installing bifacial modules in an east-west configuration can yield as much electricity as a south-facing solar panel. This flexibility opens up diverse deployment possibilities, allowing Sunzaun panels to line highways, railroads, fences, and even residential balconies. The panels demonstrate resilience, capable of withstanding wind loads of up to 0.084 psi, and are undergoing the process of obtaining UL2703 certification, ensuring safety performance.
A tangible example of Sunzaun’s effectiveness is evident at a winery in California, where a vertical system comprising 43 panels is currently installed, producing an impressive 23kW of power. This success story underscores the potential of bifacial solar panels, particularly in agrivoltaic settings. 1 2
Bifacial Solar Panels: A Catalyst for Agrivoltaic Advancements
The intersection of agrivoltaics and bifacial solar panels represents a burgeoning field with far-reaching implications for sustainable energy practices. Bifacial solar panels, a relatively recent innovation in the solar industry, capture not only direct sunlight but also diffused or reflected sunlight that strikes the back of the panel. This design enhances energy-harvesting capabilities, making bifacial panels more efficient than their conventional counterparts.
While the additional materials and technology on the backside of bifacial panels incur higher costs, the potential for more efficient space utilization in dual-use projects makes them an attractive option. Agrivoltaics, which involves the deployment of solar panels on raised structures within agricultural areas, opens up opportunities for combining renewable energy generation with farming activities, grazing lands, and pollinator habitats.
The economic viability of these dual-use projects is a critical consideration, and research in Chile suggests that bifacial solar panels could play a pivotal role in expanding agrivoltaic practices globally. In 2020, solar developer BlueWave Solar unveiled plans for a solar-plus-farming project in Massachusetts, featuring bifacial solar panels. These panels, with the ability to capture ground-reflected sunlight, sparked interest in exploring various ground coverings, including vegetation, to enhance solar cell efficiency on farmland.
One of the key advantages of bifacial technology is its potential for more efficient use of available space for electricity generation. As research and development in the bifacial field mature, costs have been decreasing, making these panels more accessible for agrivoltaic applications. The combination of solar panels and farming activities aligns with principles of regenerative agriculture, prioritizing soil health and sustainability.
Agrivoltaic arrays, with raised solar panels and strategic design features, facilitate farming activities within the array while preserving farmland and offering additional economic benefits. The shade created by the panels contributes to a microclimate that can enhance crop yields, and the panels themselves act as a barrier against wind, reducing soil erosion.
A recent study in Chile explored the use of vertical agrivoltaics, specifically vertical bifacial solar panels, and its potential impact on electricity production and agricultural water demand. The findings highlighted that vertical agrivoltaics could generate renewable energy while reducing the water demand for irrigated crops. The study compared conventional solar arrays with vertical bifacial systems, noting that the latter, while producing slightly less electricity, had a significantly lower impact on agricultural activities.
Moreover, the research suggested that the energy output pattern from vertical arrays could be advantageous in regions already saturated with solar power during peak midday periods. The lower impact on the grid, coupled with the potential for water conservation related to shading, positions vertical agrivoltaics as a promising avenue for sustainable energy and agricultural practices. 3
Evaluating the Economics of Agrivoltaics: A Holistic Approach
The economic viability of agrivoltaic projects is often assessed through the lens of the levelized cost of energy (LCOE), providing a baseline for comparing the costs of different energy resources and projects. However, stakeholders in the energy industry are increasingly questioning the sole reliance on LCOE, especially when considering the impracticality of alternative energy options.
Chile, facing challenges such as prolonged droughts impacting the honey industry, offers a unique perspective on the intersection of agrivoltaics and economic considerations. The importance of bees to agriculture and the country’s honey export industry underscores the need for holistic solutions.
A research project presented at the American Institute of Physics conference challenged the conventional LCOE calculation in favor of a more comprehensive approach. The study, titled “Price for covering cropland with an agrivoltaic system: PV panels replacing shading nets in Chilean blueberry cultivation,” focused on using solar panels as an alternative to disposable plastic nets used for crop protection.
The research emphasized that solely evaluating the economics of photovoltaic (PV) systems does not capture the synergistic effects that agrivoltaics can have on agriculture. By comparing the agrivoltaic solution with conventional practices, the study found notable synergies, particularly when considering the costs associated with plastic covers. While plastic nets may be inexpensive for a single year, the ongoing replacement and installation costs over subsequent years make them less economically competitive than solar arrays, which typically have a lifespan of 20-25 years.
The study highlighted that limiting additional capital expenditure (CAPEX) to around $150/kWp could make the price for crop cover with agrivoltaic systems competitive with shading nets. This innovative approach to economic evaluation underscores the potential for agrivoltaics to offer not only sustainable energy solutions but also economic advantages in agricultural settings.
Ongoing research in Chile, led by Germany’s Fraunhofer Institute, further explores the multifaceted benefits of agrivoltaics. The intersection of regenerative agriculture, organic farming, and agrivoltaics presents a compelling case for easing pressure on the honey industry and promoting sustainable land management practices.
Unlocking the Mysteries of Vertical PV Systems
Recent research conducted by the Netherlands Organisation for Applied Scientific Research (TNO) delves into the unexpected yield gains observed in vertical photovoltaic (PV) systems compared to horizontal arrays. Vertical PV systems, characterized by their unique design, have been found to exhibit lower operating temperatures, contributing to higher energy yields.
The study, titled “Thermal model in digital twin of vertical PV system helps to explain unexpected yield gains,” explores the factors influencing the performance of vertical installations. The research, published in EPJ Photovoltaics, utilizes digital twins—virtual representations of real-world assets—to create models of real PV systems for analysis.
The key finding of the study is that vertical PV systems experience significantly lower operating temperatures compared to free-standing fixed tilt PV systems with the same total irradiance. Lower operating temperatures positively impact the operating voltage of solar cells, leading to increased energy generation, especially under high irradiance conditions.
The voltage in solar cells is influenced by both the amount of light and the temperature of the cells. While increasing irradiance conditions lead to a logarithmic increase in voltage, higher temperatures result in a decrease in voltage. For standard PV systems, the increase in voltage due to light is offset by the decrease in voltage due to higher operating temperatures. However, vertical PV systems exhibit a more balanced increase in voltage and decrease in voltage, contributing to their unexpected yield gains.
The study conducted by TNO used digital twins to model a vertical PV system located near their facilities in Petten, the Netherlands. The vertical array, featuring east-west orientation and bifacial modules, demonstrated a heat transfer coefficient nearly double that of horizontal panels. The vertical array operated at a temperature difference with respect to ambient that was nearly halved, resulting in a 2.5% higher annual energy yield.
This research sheds light on the importance of considering the actual operating conditions of emerging applications of solar panels. The lower operating temperatures observed in vertical PV systems not only contribute to increased energy yields but also have a slowing effect on degradation mechanisms. The findings suggest that the impact of lower operating temperatures could be even more significant in regions with higher irradiance conditions.
As the solar industry continues to explore innovative designs and technologies, vertical PV systems emerge as a promising avenue for enhancing energy generation efficiency. The unique characteristics of vertical installations, coupled with the insights gained from studies like TNO’s, pave the way for advancements in solar energy production. 4
Over Easy Solar’s Novel Approach to Vertical Solar Arrays
In the realm of vertical solar systems, Over Easy Solar, a Norwegian specialist, has pioneered a novel approach to deployment. Over Easy Solar recently supplied a 102 kW bifacial commercial rooftop system, following a successful installation of a 45 kWp system on a school rooftop. What sets Over Easy Solar apart is its focus on green rooftops, where solar arrays are integrated with vegetation.
The 102 kW installation, covering 1200 m2 on a flat-roofed commercial building in Oslo, showcases Over Easy Solar’s low-height, all-in-one system design. This system, termed a “vertical photovoltaic (VPV) unit,” comes pre-assembled as a single unit containing unconventional heterojunction bifacial modules, the mounting rack, and cabling. The prefabricated VPV units offer a plug-and-play solution for flat and green rooftop solar installations.
Over Easy Solar’s unique glass-glass modules, made with 3.2 mm solar glass, boast up to 95% bifaciality and operate within a temperature range of -40°C to 85°C. The company’s approach reduces the need for ballast units, thanks to the low height and weight of the system. This not only simplifies installation but also contributes to a lighter overall weight, enhancing ease of deployment.
The success of Over Easy Solar’s green rooftop pilot project at an Oslo school demonstrated energy yields that were 20-30% higher than conventional east-west flat rooftop installations in the same area. The integration with rooftop vegetation proved to be a synergistic solution, aligning with the principles of agrivoltaics.
Over Easy Solar’s commitment to vertical solar arrays extends to its innovative approach to modeling and analysis. Collaborating with researchers from the Institute for Energy Technology in Norway, the company explored the heat exchange dynamics of vertical panels. The results indicated that vertical panels exhibited much higher heat exchange than expected for tilted solar panels, contributing to their enhanced performance.
As the solar industry continues to embrace the potential of vertical installations, Over Easy Solar’s advancements underscore the multifaceted benefits of integrating solar energy with green rooftop landscapes. The combination of efficient energy generation, reduced operating temperatures, and compatibility with regenerative agriculture positions vertical solar arrays as a promising solution for sustainable urban and agricultural development. 5
Conclusion
The evolving landscape of solar energy and agrivoltaics is marked by innovative designs, technological advancements, and a commitment to sustainability. From Sunzaun’s boundary-defying vertical solar panels to the economic considerations of agrivoltaic projects, the intersection of solar energy and agriculture is yielding groundbreaking solutions. The emergence of bifacial solar panels as a catalyst for agrivoltaic potential, coupled with the mysteries unlocked by vertical PV systems, points toward a future where renewable energy and sustainable land use harmoniously coexist. As the journey continues, these developments pave the way for a greener, more sustainable energy landscape, where the sun’s power is harnessed creatively and efficiently for the benefit of both the environment and humanity.
- These new vertical solar systems are specially designed for farms
- Vertical solar panels could save farm land and transform agriculture
- Bifacial Solar Panels To Open Floodgates Of Agrivoltaic Potential
- Researchers shed light on mysterious, higher energy yields in vertical PV systems
- Vertical rooftop PV specialist switches on two more systems on green roofs in Norway
