Argonne National Laboratory: Perovskite Solar Technology Shows Quick Energy Returns: As little as 2 to 3 Months


perovskiteso 072315This graphic shows the semi-cubic structure of perovskite materials, and how they would fit into a solar power device. An Argonne-Northwestern study found that perovskite-based solar technology has the quickest energy payback time of all …more

Solar panels are an investment—not only in terms of money, but also energy. It takes energy to mine, process and purify raw materials, and then to manufacture and install the final product.

Silicon-based panels, which dominate the market for solar power, usually need about two years to return this energy investment. But for technology made with perovskites—a class of materials causing quite a buzz in the solar research community—the energy payback time could be as quick as two to three months.

By this metric, perovskite modules are better than any that is commercially available today.

These are the findings of a study by scientists at Northwestern University and the U.S. Department of Energy’s Argonne National Laboratory. The study took a broad perspective in evaluating solar technology: In what’s called a cradle-to-grave life cycle assessment, scientists traced a product from the mining of its until its retirement in a landfill. They determined the ecological impacts of making a solar panel and calculated how long it would take to recover the energy invested.ANL_PMS_P_H

Perovskite technology has yet to be commercialized, but researchers everywhere are excited about the materials. Most projects, however, have been narrowly focused on conversion efficiency—how effectively the technology transforms sunlight into useable energy.

“People see 11 percent efficiency and assume it’s a better product than something that’s 9 percent efficient,” said Fengqi You, corresponding author on the paper and assistant professor of chemical and biological engineering at Northwestern. “But that’s not necessarily true.”

A more comprehensive way to compare solar technology is the energy payback time, which also considers the energy that went into creating the product.

This study looked at the energy inputs and outputs of two perovskite modules. A solar panel consists of many parts, and the module is the piece directly involved in converting energy from one form into another—sunlight into electricity.

Perovskites lag behind silicon in conversion efficiency, but they require much less energy to be made into a solar module. So perovskite modules pull ahead with a substantially shorter energy payback time—the shortest, in fact, among existing options for solar power.

“Appreciating energy payback times is important if we want to move perovskites from the world of scientific curiosity to the world of relevant commercial technology,” said Seth Darling, an Argonne scientist and co-author on the paper.

To get a complete picture of the environmental impacts a perovskite panel could have, the researchers also analyzed metals used for electrodes and other parts of the device.

One of the modules tested includes lead and gold, among other metals. Many perovskite models have lead in their active layer, which absorbs sunlight and plays a leading role in conversion efficiency. People in the research community have expressed concern because everyone knows lead can be toxic, Darling said.

Surprisingly, the team’s assessment showed that gold was much more problematic.

Gold isn’t typically perceived as hazardous, but the process of mining the precious metal is extremely damaging to the environment. The module in this study uses gold in its positive electrode, where charges are collected in the process of generating electricity.

The harmful effects of gold mining, an indirect impact of this particular perovskite technology, is something that could only be uncovered by a cradle-to-grave investigation, said Jian Gong, the study’s first author and a PhD student in You’s research group at Northwestern.

The team hopes that future projects use this same zoomed-out approach to identify the best materials and manufacturing processes for the next generation of solar technology—products that will have to be environmentally sustainable and commercially viable.

“Soon, we’re going to need to produce an extremely high number of ,” You said. “We don’t have time for trial-and-error in finding the ideal design. We need a more rigorous approach, a method that systematically considers all variables.”

While this paper featured a thorough environmental assessment of different solar power options, further studies are needed to factor in economic costs. Before putting a perovskite panel on the market, scientists will likely have to replace gold and other unsustainable materials, for both environmental and economic reasons, Darling said.

In addition, extending the lifetime of perovskite modules will be important in order to make sure they are stable enough for long-term commercial use, You said. Despite a few necessary improvements, he said perovskite technology could be commercialized within two years if researchers use comprehensive analysis to optimize the selection of raw materials and manufacturing.

One of the motivations for this study, according to the authors, was the need to improve technology so that solar energy can be scaled up in a big way.

Global energy demand is expected to nearly double by 2050, and Darling said there’s no question that must contribute a significant fraction.

The real question, Darling said, is “How quickly do we have to get a technology to market to save the planet? And how can we make that happen?”

Explore further: Solar panel manufacturing is greener in Europe than China, study says

More information: “Perovskite photovoltaics: life-cycle assessment of energy and environmental impacts.” Energy Environ. Sci., 2015,8, 1953-1968 DOI: 10.1039/C5EE00615E

Northwestern University: $9.8 Million Award from Air Force: Bioprogrammable Nano-Materials


 

US Air Force Sym AF%20Symbol%20New%20Blue[1]Northwestern University’s International Institute for Nanotechnology has been awarded a U.S. Air Force Center of Excellence grant to design advanced bioprogrammable nanomaterials.
The goal is to develop solutions to challenging problems in the areas of energy, the environment, security and defense, as well as for developing ways to monitor and mitigate human stress.
The five-year, $9.8 million grant establishes the Center of Excellence for Advanced Bioprogrammable Nanomaterials, the only one of its kind in the country. After the initial five years, the grant potentially could be renewed for an additional five years.
“Northwestern University was chosen to lead this Center of Excellence because of its investment in infrastructure development, including new facilities and instrumentation; its recruitment of high-caliber faculty members and students; and its track record in bio-nanotechnology and cognitive sciences,” said Timothy Bunning, chief scientist at the U.S. Air Force Research Laboratory (AFRL) Materials and Manufacturing Directorate.
Led by IIN Director Chad A. Mirkin, C-ABN will support collaborative, discovery-based research projects aimed at developing bioprogrammable nanomaterials that will meet both military and civilian needs and facilitate the efficient transition of these new technologies from the laboratory to marketplace.Northwestern U 945-crest-250-200-69f66bc4e09bf96305a6c6516f183c63
Bioprogrammable nanomaterials are structures that typically contain a biomolecular component, such as nucleic acids or proteins, which give the materials a variety of novel capabilities.
Nanomaterials can be designed to assemble into large 3-D structures, to interface with biological structures inside cells or tissues, or to interface with existing macroscale devices, for example. These new bioprogrammable nanomaterials and the fundamental knowledge gained through their development will ultimately lead to the creation of wearable, portable and/or human-interactive devices with extraordinary capabilities that will significantly impact both civilian and Air Force needs.
In one research area, scientists will work to understand the molecular underpinnings of vulnerability and resilience to stress. They will use bioprogrammable nanomaterials to develop ultrasensitive sensors capable of detecting and quantifying biomarkers for human stress in biological fluids (e.g., saliva, perspiration or blood), providing means to easily monitor the soldier during times of extreme stress. Ultimately, these bioprogrammable materials may lead to methods to increase human cellular resilience to the effects of stress and/or to correct genetic mutations that decrease cellular resilience of susceptible individuals.
Other research projects, encompassing a wide variety of nanotechnology-enabled goals, include:
  • Developing hybrid wearable energy-storage devices;
  • Developing devices to identify chemical and biological targets in a field environment;
  • Developing flexible bio-electronic circuits;
  • Designing a new class of flat optics; and
  • Advancing understanding of design rules between 2-D and 3-D architectures.
The analysis of these nanostructures also will extend fundamental knowledge in the fields of materials science and engineering, human performance, chemistry, biology and physics.
The center will be housed under the IIN, providing researchers with access to IIN’s entrepreneurial community and its close ties with Northwestern’s Kellogg School of Management.
“This collaborative and dynamic relationship has resulted in the founding of more than 20 successful startup companies over the past 10 years, working through the university’s Innovation and New Ventures Office,” Mirkin said. He is the George B. Rathmann Professor of Chemistry in Northwestern’s Weinberg College of Arts and Sciences.
The center also will provide opportunities for graduate students and postdoctoral fellows to work with researchers at AFRL laboratories.
“The integration of learning and real-world experience is a critical component of Northwestern’s strategic plan,” Vice President of Research Jay Walsh said. “The new Center of Excellence will provide unique opportunities that will help to position our students to become the leading researchers of tomorrow.”
Source: Northwestern University