Nanocellulose infused with red onion extract shields solar cells from UV degradation

by Robert Schreiber

Berlin, Germany (SPX) Mar 20, 2025

Researchers at the University of Turku in Finland have developed a bio-based film that provides high-performance UV protection for solar cells, utilizing nanocellulose treated with red onion skin extract. This marks the first comparative study of how various bio-derived UV filters perform over time.

Solar cells, susceptible to damage from ultraviolet radiation, are typically shielded by petroleum-derived films such as polyvinyl fluoride (PVF) or polyethylene terephthalate (PET). In an effort to reduce reliance on fossil fuels, researchers are exploring sustainable alternatives like nanocellulose, a material made by refining cellulose into nanoscale fibers that can be customized for UV blocking capabilities.

The study, conducted in collaboration with Aalto University in Finland and Wageningen University in the Netherlands, revealed that nanocellulose films dyed with red onion extract blocked 99.9% of UV rays up to 400 nanometres. This performance surpassed that of commercial PET-based filters, which served as a benchmark in the research.

“Nanocellulose films treated with red onion dye are a promising option in applications where the protective material should be bio-based,” stated Doctoral Researcher Rustem Nizamov from the University of Turku.

Researchers evaluated four types of nanocellulose films enhanced with red onion extract, lignin, or iron ions, all known for their UV-filtering properties. Among them, the film incorporating red onion extract demonstrated the most effective UV shielding.

Effective UV protection must be balanced with the ability to transmit visible and near-infrared light, essential for solar energy conversion. While materials like lignin excel in UV absorption, their dark hue hinders transparency. In contrast, the red onion-based film achieved over 80% light transmission at wavelengths between 650 and 1,100 nanometres, maintaining this level over extended testing.

To simulate prolonged outdoor use, the films were exposed to artificial light for 1,000 hours, equating to roughly one year of natural sunlight in central Europe. Researchers tracked changes in the films and solar cells through digital imaging.

“The study emphasised the importance of long-term testing for UV filters, as the UV protection and light transmittance of the other bio-based filters changed significantly over time. For example, the films treated with iron ions had good initial transmittance which reduced after aging,” tells Nizamov.

Tests focused on dye-sensitised solar cells, which are particularly prone to UV-induced deterioration. The findings also have broader implications for other solar technologies like perovskite and organic photovoltaics, where bio-based UV filters could play a crucial role.

“These results are also relevant for the UV protection of other types of solar cells, including perovskite and organic photovoltaics, as well as any application where the use of a bio-based UV filter is paramount,” Nizamov says.

Looking ahead, the researchers aim to create biodegradable solar cells that could serve as power sources in applications such as food packaging sensors.

“The forest industry is interested in developing new high-grade products. In the field of electronics, these may also be components for solar cells,” noted Kati Miettunen, Professor in Materials Engineering.

The University of Turku’s Solar Energy Materials and Systems (SEMS) group is exploring ways to integrate solar technologies into broader energy systems.

This work was part of the BioEST project, supported by the Research Council of Finland.

Sustainable Nanocellulose UV Filters for Photovoltaic Applications: Comparison of Red Onion (Allium cepa) Extract, Iron Ions, Research Report:and Colloidal Lignin

Related Links

University of Turku

All About Solar Energy at SolarDaily.com

Space Solar teams with MagDrive to boost in-orbit solar power systems

by Sophie Jenkins

London, UK (SPX) Mar 20, 2025

Space Solar, a leading force in the field of space-based solar power (SBSP), has formed a strategic alliance with UK propulsion technology company Magdrive to enhance the deployment of large-scale infrastructure in orbit. The agreement, unveiled during the Farnborough International Space Show (FISS), is formalized under the Space Propulsion and Infrastructure Innovation Initiative (SPI3), reflecting a concerted push to realize space-driven clean energy.

SPI3 is designed to help fulfil the UK’s long-term goal of producing scalable, sustainable energy directly from space. By integrating Magdrive’s advanced propulsion systems, the initiative addresses the complex challenge of transporting, assembling, and managing substantial SBSP infrastructure in orbit.

Space Solar plans to launch its first 30-megawatt SBSP platform within five years, and success hinges on the ability to control and maintain massive solar satellite structures. Magdrive’s propulsion solutions are poised to support upcoming demonstration missions by enabling essential orbital maneuvers, satellite assembly, and shape optimization.

“Innovation in propulsion is essential to making large-scale space infrastructure a reality,” said Sam Adlen, Co-CEO of Space Solar. “Space Solar and Magdrive share a vision of advancing sustainable space operations that benefit earth, and this collaboration will pave the way for new propulsion solutions that will be indispensable for space-based solar power and other large scale space infrastructure.”

This partnership is also set to strengthen the UK’s space sector by stimulating high-value job creation and technological advancement. It highlights the country’s dedication to leading innovation at the intersection of clean energy and aerospace.

As part of SPI3, both companies will collaborate on refining propulsion specifications tailored to SBSP systems and identify additional applications for these technologies within the broader context of UK-led space initiatives. The cooperation is a key step towards expanding the UK’s footprint in the global space economy and unlocking emerging opportunities in space-based energy markets.

“We’re excited to work with Space Solar, they’re building the future of space energy and infrastructure on a scale never seen before. By working together we’ll be propelling the space industry towards enabling sustainable life on earth. Here’s to the new space age!” said Mark Stokes, CEO, MagDrive.

United by a vision to deliver scalable energy solutions from space, Space Solar and Magdrive’s agreement represents a pivotal move toward the commercialization of SBSP. As Space Solar progresses toward critical mission milestones, incorporating Magdrive’s propulsion technology will bring the reality of space-derived clean energy closer than ever.

Related Links

Space Solar

All About Solar Energy at SolarDaily.com

Reusing old oil and gas wells may offer green energy storage solution

by Matthew Carroll for Penn News

University Park PA (SPX) Mar 19, 2025

Moving from fossil fuels to renewable energy sources like wind and solar will require better ways to store energy for use when the sun is not shining or the wind is not blowing. A new study by researchers at Penn State found that taking advantage of natural geothermal heat in depleted oil and gas wells can improve the efficiency of one proposed energy storage solution: compressed-air energy storage (CAES).

CAES plants compress air and store it underground when energy demand is low and then extract the air to create electricity when demand is high. But startup costs currently limit commercial development of these projects, the scientists said.

The researchers proposed a new geothermal-assisted compressed-air energy storage system that makes use of depleted oil and gas wells – the Environmental Protection Agency estimates there are around 3.9 million in the United States – and found it can improve efficiency by 9.5% over the existing technology. This means a larger percentage of the energy stored in the system can be recovered and turned into electricity, potentially boosting profits for operators.

“This improvement in efficiency can be a game changer to justify the economics of compressed-air energy storage projects,” said Arash Dahi Taleghani, professor of petroleum and natural gas engineering at Penn State and corresponding author on the study. “And on top of that, we could significantly avoid the upfront cost by using existing oil and gas wells that are no longer in production. This could be a win, win situation.”

Reusing depleted oil and gas wells would allow operators to access geothermal heat in hot rock formations underground, eliminating upfront costs of drilling new wells and potentially making the technology more appealing to industry, the scientists said.

Gases like compressed air increase in pressure as temperatures increase, meaning the heated wells could potentially store more energy, according to Taleghani. When electricity is needed, the heated, compressed air is released, driving a turbine to produce power.

“Without taking advantage of the geothermal setup, you could not get enough encouraging numbers,” Taleghani said, explaining that the team used numerical modeling simulations to find that placing CAES systems in abandoned oil and gas wells significantly increased the air temperature in the systems. “And on top of that, drilling new wells may not justify the economics of this type of storage. But by combining these two factors, and by going back and forth through modeling and simulation, we found this could be a very good solution.”

Energy storage options like CAES are particularly important in the transition to clean energy, according to the researchers, because they help address the intermittent nature of renewable sources. By storing excess renewable energy and releasing it when needed, energy storage contributes to grid stability and reliability.

“The problem is that sometimes when we need energy, there is no sunshine or there is no wind,” Taleghani said. “That’s a big barrier against further expansion of most of the renewable energy that is available to us. That’s why it’s very important to have some storage capacity to support the grid.”

Repurposing depleted oil and gas wells may also help mitigate potential environmental impacts of abandoned wells and potentially provide new job opportunities in areas with rich energy industry traditions, the researchers said.

In Pennsylvania alone, regulators estimate there are hundreds of thousands of orphaned and abandoned wells. If these wells are improperly plugged, or damaged, they can leak methane into the atmosphere and groundwater.

“If we use existing wells, we are basically hitting two birds with one stone,” Taleghani said. “First, we are sealing these wells. That stops any potential leaks. And then if we are repurposing these wells for energy storage, we are still using the infrastructure that is in place in these communities. It can potentially maintain employment in the area and allow communities to be part of the energy future.”

This research was conducted as part of the Repurposing Center for Energy Transition (ReCET) at Penn State. The center seeks to repurpose fossil energy infrastructure for energy transition applications, especially in legacy energy communities.

Also contributing from Penn State were Derek Elsworth, G. Albert Shoemaker Chair in Mineral Engineering and professor of energy and geo-environmental engineering, and Qitao Zhang, a postdoctoral scholar, both in the John and Willie Leone Family Department of Energy and Mineral Engineering.

Research Report:Underground energy storage using abandoned oil and gas wells assisted by geothermal

Related Links

Penn State

Powering The World in the 21st Century at Energy-Daily.com