Solar Energy

Inverted perovskite solar cell breaks 25% efficiency record

Published

1 year ago

November 21, 2023

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Inverted perovskite solar cell breaks 25% efficiency record

by Staff Writers

Evanston IL (SPX) Nov 21, 2023

Northwestern University researchers have raised the standards again for perovskite solar cells with a new development that helped the emerging technology hit new records for efficiency. The findings, published Nov. 17 in the journal Science, describe a dual-molecule solution to overcoming losses in efficiency as sunlight is converted to energy.

By incorporating first, a molecule to address something called surface recombination, in which electrons are lost when they are trapped by defects – missing atoms on the surface, and a second molecule to disrupt recombination at the interface between layers, the team achieved a National Renewable Energy Lab (NREL) certified efficiency of 25.1% where earlier approaches reached efficiencies of just 24.09%.

“Perovskite solar technology is moving fast, and the emphasis of research and development is shifting from the bulk absorber to the interfaces,” said Northwestern professor Ted Sargent. “This is the critical point to further improve efficiency and stability and bring us closer to this promising route to ever-more-efficient solar harvesting.”

Sargent is the co-executive director of the Paula M. Trienens Institute for Sustainability and Energy (formerly ISEN) and a multidisciplinary researcher in materials chemistry and energy systems, with appointments in the department of chemistry in the Weinberg College of Arts and Sciences and the department of electrical and computer engineering in the McCormick School of Engineering.

Conventional solar cells are made of high-purity silicon wafers that are energy-intensive to produce and can only absorb a fixed range of the solar spectrum.

Perovskite materials whose size and composition can be adjusted to “tune” the wavelengths of light they absorb, making them a favorable and potentially lower-cost, high-efficiency emerging tandem technology.

Historically perovskite solar cells have been plagued by challenges to improve efficiency because of their relative instability. Over the past few years, advances from Sargent’s lab and others have brought the efficiency of perovskite solar cells to within the same range as what is achievable with silicon.

In the present research, rather than trying to help the cell absorb more sunlight, the team focused on the issue of maintaining and retaining generated electrons to increase efficiency. When the perovskite layer contacts the electron transport layer of the cell, electrons move from one to the other. But the electron can move back outward and fill, or “recombine” with holes that exist on the perovskite layer.

“Recombination at the interface is complex,” said first author Cheng Liu, a postdoctoral student in the Sargent lab, which is co-supervised by the Charles E. and Emma H. Morrison Professor of Chemistry Mercouri Kanatzidis. “It’s very difficult to use one type of molecule to address complex recombination and retain electrons, so we considered what combination of molecules we could use to more comprehensively solve the problem.”

Past research from Sargent’s team has found evidence that one molecule, PDAI2, does a good job at solving interface recombination. Next they needed to find a molecule that would work to repair surface defects and prevent electrons from recombining with them.

By finding the mechanism that would allow PDAI2 to work with a secondary molecule, the team narrowed in on sulfur, which could replace carbon groups – typically poor at preventing electrons from moving – to cover missing atoms and suppress recombination.

A recent paper by the same group published in Nature developed a coating for the substrate beneath the perovskite layer to help the cell work at a higher temperature for a longer period. This solution, according to Liu, can work in tandem with the findings within the Science paper.

While the team hopes their findings will encourage the larger scientific community to continue moving the work forward, they too will be working on follow-ups.

“We have to use a more flexible strategy to solve the complex interface problem,” Cheng said. “We can’t only use one kind of molecule, as people previously did. We use two molecules to solve two kinds of recombination, but we are sure there’s more kinds of defect-related recombination at the interface. We need to try to use more molecules to come together and make sure all molecules work together without destroying each other’s functions.”

Research Report:Bimolecularly-passivated interface enables efficient and stable inverted perovskite solar cells

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Solar Energy

Vietnam ups wind, solar targets as energy demand soars

Published

2 days ago

April 20, 2025

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Vietnam ups wind, solar targets as energy demand soars

by AFP Staff Writers

Hanoi (AFP) April 17, 2025

Vietnam has dramatically increased its wind and solar targets as it looks to up its energy production by 2030 to meet soaring demand, according to a revised version of its national power plan.

The Southeast Asian country has committed to reaching net-zero carbon emissions by 2050 and the latest edition of its Power Development Plan 8 (PDP8), as it is known, maps out how it will reach those goals.

The manufacturing powerhouse has been heavily reliant on coal to meet its rapidly expanding energy needs. But now it wants to “strongly develop renewable energy sources”, according to the plan, which was published Wednesday on the government’s news portal.

With targets set at 73 gigawatts (GW) for solar and 38 GW for onshore wind energy by 2030 — and a significant increase to 296 GW and 230 GW by 2050 — the plan looks “really ambitious”, said Andri Prasetiyo, senior researcher at Senik Centre Asia.

The 2023 version of the PDP8 aimed for 12.8 GW for solar and 21 GW for wind by the end of the decade.

“I think this sends a clear message, Vietnam is positioning itself to maintain leadership in Southeast Asia’s clean energy transition, (even) taking a more prominent role in the region,” he told AFP.

Solar power grew rapidly in Vietnam until 2020 but its success hit a roadblock due to infrastructure limitations.

Prasetiyo said Vietnam’s new targets were “increasingly feasible”, although they far outstrip market projections of what the country can achieve.

– Coal, nuclear –

The latest version of the PDP8, which was approved this week, also re-emphasises the country’s 2023 pledge to end the use of coal by 2050.

Coal will represent nearly 17 percent of its energy mix by the end of the decade, down from a target of 20 percent set in 2023.

Meanwhile, solar will account for 31 percent of the country’s energy by 2030, while onshore wind will be 16 percent.

More than $136 billion will be needed if Vietnam is to get there, the document said.

Under the new plan, the country also aims to open its first nuclear power plant by 2035 at the latest.

It comes after Vietnam and Russia signed an agreement on nuclear energy in January, with Hanoi saying Russian nuclear giant Rosatom was “very interested” in cooperating on a project in central Ninh Thuan province.

Overall, as Vietnam targets an ambitious 10 percent economic growth rate by the end of the decade, it wants to raise its total installed capacity to a maximum of 236 GW by that date.

That’s up by more than 80 GW from the figure outlined in 2023.

Hanoi is also eager to avoid a repeat of the rolling blackouts and sudden power outages in summer 2023 that led to losses among manufacturers. They also prompted massive disruption for residents, as intensely hot weather and unprecedented drought strained energy supplies in northern Vietnam.

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Solar Energy

New system offers early warning of dust storms to protect solar power output

Published

6 days ago

April 16, 2025

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New system offers early warning of dust storms to protect solar power output

by Simon Mansfield

Sydney, Australia (SPX) Apr 10, 2025

A new predictive platform called iDust is poised to transform dust storm forecasting and improve solar energy output in dust-prone regions. Developed by researchers at the Chinese Academy of Sciences, iDust offers high-resolution, fast-turnaround dust forecasts that could help mitigate power losses across solar farms, particularly in arid zones.

The tool was created under the leadership of Dr. Chen Xi from the Institute of Atmospheric Physics and detailed in the Journal of Advances in Modeling Earth Systems (JAMES).

“Dust storms not only block sunlight but also accumulate on solar panels, decreasing their power output.” said Chen, outlining the motivation behind the project. With China’s rapid expansion of solar installations in desert areas, the need for precise and timely dust forecasts has become increasingly urgent to avoid operational disruptions and revenue shortfalls.

Traditional systems like those from the European Centre for Medium-Range Weather Forecasts (ECMWF) often lack the spatial resolution and processing speed needed for optimal solar planning. iDust addresses these limitations by embedding dust-related dynamics directly into its forecast engine. This allows the system to generate forecasts with 10-kilometer resolution-a fourfold improvement over previous models-while maintaining near-parity in computational load. Crucially, iDust can deliver 10-day forecasts within six hours of initial observations.

The effectiveness of iDust was put to the test on April 13, 2024, when it successfully tracked a severe dust storm over Bayannur in northern China. Such storms can distort solar energy projections by as much as 25% if unaccounted for, underscoring the value of integrating dust modeling into energy planning.

Designed for practical deployment, iDust aims to assist solar facility operators and grid managers in optimizing power production and reducing losses due to airborne particulates. As China pushes toward its carbon neutrality goals, innovations like iDust will be central to achieving sustainable energy reliability.

Researchers plan to expand the system for global application, allowing other countries with desert-based solar assets to benefit from enhanced dust forecasting.

Research Report:The Efficient Integration of Dust and Numerical Weather Prediction for Renewable Energy Applications

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Solar Energy

Solar park boom threatens Spain’s centuries-old olive trees

Published

6 days ago

April 15, 2025

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Solar park boom threatens Spain’s centuries-old olive trees

By Rosa SULLEIRO

Lopera, Spain (AFP) April 14, 2025

At his farm in southern Spain, Francisco Campos looked worriedly at a green sea of centuries-old olive trees that he fears will face the axe to make way for a proposed solar park.

“Cutting down olive trees to install solar panels is a crime,” the 64-year-old farmer told AFP in Lopera, a town of whitewashed buildings with 3,600 residents in the sunny southern region of Andalusia, Spain’s olive-growing heartland.

Spain is the world’s top producer of olive oil, but the fertile agricultural land long used by olive producers is now in high demand from power firms looking to install solar farms.

And with nearly 3,000 hours of sunshine per year, Andalusia is one of the Spanish regions with the highest number of solar panels as a renewables boom makes the country a European leader in green energy.

Renewable energy firms such as Greenalia and FRV Arroyadas have requested permission to build multiple solar farms near Lopera, which farmers say will affect up to 1,000 hectares (2,500 acres) of property.

The businesses negotiated agreements to lease the bulk of the land required for their projects but encountered significant opposition from hundreds of small landowners.

This prompted the regional government of Andalusia to announce it will expropriate some land needed for the plants, declaring them to be in “the public interest”.

“Is it in the public interest for them to take my land and give it to a company so that the company can profit? This has no benefit for us,” said Campos.

“Our way of life is going to be destroyed,” he added.

– ‘From our ancestors’ –

Campaigners predict that the eight solar projects planned for the area will require the removal of nearly 100,000 olive trees.

The regional government puts the figure significantly lower, at 13,000.

Local residents anticipated power companies would seek to install solar panels in the area, but they never imagined “they would come and take away your property,” said Rafael Alcala, a spokesman for a platform that represents the solar plants’ opponents.

In support of landowners impacted by the latest round of expropriations, dozens of farmers on tractors — some holding signs that read “We don’t want solar plants” — gathered on a recent morning outside Lopera.

“These lands come from our ancestors. What am I going to leave to my children now?” Maria Josefa Palomo, a 67-year-old pensioner, said at the protest.

Losing 500 hectares of olive groves would wipe out more than two million euros ($2.3 million) in annual revenues, according to local olive oil cooperative La Loperana.

Campaigners say 5,000 olive trees have already been uprooted from land belonging to a farmer in Lopera who signed an agreement with one of the firms behind a solar park. More could follow.

In an effort to stop the projects, opponents have filed lawsuits against the regional government and the companies involved.

– ‘Until the end’ –

Spain generated a record 56.8 percent of its electricity last year from renewable sources such as wind and solar, according to grid operator Red Electrica.

Leveraging on its sunny plains, windy hillsides and fast-flowing rivers, Spain intends to raise the share of renewable-generated electricity to 81 percent of the total by 2030 as part of efforts to reduce its greenhouse gas emissions.

The regional government has defended the renewables projects, saying less than one percent of the land they use in the region had to be expropriated from reluctant landowners.

Spanish solar industry group UNEF, which represents more than 800 companies, says the projects boost tax revenues in rural communities.

They generate “significant amounts” that can be used to improve public services, said UNEF head Jose Donoso.

Solar park opponents in Lopera disagree and vow to continue their fight.

“Until the end. Nobody is going to take what is ours away from us,” said Juan Cantera, a 28-year-old farmer.

“Olive oil is everything in Lopera”.

rs/ds/imm/gv/tym

RED ELECTRICA CORPORACION

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