MIT, Harvard and Mass General lead 408 MW green energy push

by Nicole Morell | MIT Office of Sustainability

Boston MA (SPX) Nov 25, 2024

MIT is co-leading an effort to enable the development of two new large-scale renewable energy projects in regions with carbon-intensive electrical grids: Big Elm Solar in Bell County, Texas, came online this year, and the Bowman Wind Project in Bowman County, North Dakota, is expected to be operational in 2026. Together, they will add a combined 408 megawatts (MW) of new renewable energy capacity to the power grid. This work is a critical part of MIT’s strategy to achieve its goal of net-zero carbon emissions by 2026.

The Consortium for Climate Solutions, which includes MIT and 10 other Massachusetts organizations, seeks to eliminate close to 1 million metric tons of greenhouse gases each year – more than five times the annual direct emissions from MIT’s campus – by committing to purchase an estimated 1.3-million-megawatt hours of new solar and wind electricity generation annually.

“MIT has mobilized on multiple fronts to expedite solutions to climate change,” says Glen Shor, executive vice president and treasurer. “Catalyzing these large-scale renewable projects is an important part of our comprehensive efforts to reduce carbon emissions from generating energy. We are pleased to work in partnership with other local enterprises and organizations to amplify the impact we could achieve individually.”

The two new projects complement MIT’s existing 25-year power purchase agreement established with Summit Farms in 2016, which enabled the construction of a roughly 650-acre, 60 MW solar farm on farmland in North Carolina, leading to the early retirement of a coal-fired plant nearby. Its success has inspired other institutions to implement similar aggregation models.

A collective approach to enable global impact

MIT, Harvard University, and Mass General Brigham formed the consortium in 2020 to provide a structure to accelerate global emissions reductions through the development of large-scale renewable energy projects – accelerating and expanding the impact of each institution’s greenhouse gas reduction initiatives. As the project’s anchors, they collectively procured the largest volume of energy through the aggregation.

The consortium engaged with PowerOptions, a nonprofit energy-buying consortium, which offered its members the opportunity to participate in the projects. The City of Cambridge, Beth Israel Lahey, Boston Children’s Hospital, Dana-Farber Cancer Institute, Tufts University, the Mass Convention Center Authority, the Museum of Fine Arts, and GBH later joined the consortium through PowerOptions.

The consortium vetted over 125 potential projects against its rigorous project evaluation criteria. With faculty and MIT stakeholder input on a short list of the highest-ranking projects, it ultimately chose Bowman Wind and Big Elm Solar. Collectively, these two projects will achieve large greenhouse gas emissions reductions in two of the most carbon-intensive electrical grid regions in the United States and create clean energy generation sources to reduce negative health impacts.

“Enabling these projects in regions where the grids are most carbon-intensive allows them to have the greatest impact. We anticipate these projects will prevent two times more emissions per unit of generated electricity than would a similar-scale project in New England,” explains Vice President for Campus Services and Stewardship Joe Higgins.

By all consortium institutions making significant 15-to-20-year financial commitments to buy electricity, the developer was able to obtain critical external project financing to build the projects. Owned and operated by Apex Clean Energy, the projects will add new renewable electricity to the grid equivalent to powering 130,000 households annually, displacing over 950,000 metric tons of greenhouse gas emissions each year from highly carbon-intensive power plants in the region.

Complementary decarbonization work underway

In addition to investing in offsite renewable energy projects, many consortium members have developed strategies to reduce and eliminate their own direct emissions. At MIT, accomplishing this requires transformative change in how energy is generated, distributed, and used on campus. Efforts underway include the installation of solar panels on campus rooftops that will increase renewable energy generation four-fold by 2026; continuing to transition our heat distribution infrastructure from steam-based to hot water-based; utilizing design and construction that minimizes emissions and increases energy efficiency; employing AI-enabled sensors to optimize temperature set points and reduce energy use in buildings; and converting MIT’s vehicle fleet to all-electric vehicles while adding more electric car charging stations.

The Institute has also upgraded the Central Utilities Plant, which uses advanced co-generation technology to produce power that is up to 20 percent less carbon-intensive than that from the regional power grid. MIT is charting the course toward a next-generation district energy system, with a comprehensive planning initiative to revolutionize its campus energy infrastructure. The effort is exploring leading-edge technology, including industrial-scale heat pumps, geothermal exchange, micro-reactors, bio-based fuels, and green hydrogen derived from renewable sources as solutions to achieve full decarbonization of campus operations by 2050.

“At MIT, we are focused on decarbonizing our own campus as well as the role we can play in solving climate at the largest of scales, including supporting a cleaner grid in line with the call to triple renewables globally by 2030. By enabling these large-scale renewable projects, we can have an immediate and significant impact of reducing emissions through the urgently needed decarbonization of regional power grids,” says Julie Newman, MIT’s director of sustainability.

+ Fast Forward: MIT’s Climate Action Plan for the Decade

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Engineers develop additive for affordable renewable energy storage

by Clarence Oxford

Los Angeles CA (SPX) Nov 25, 2024

Advancing the promise of renewable energy sources like solar and wind, University of Wisconsin – Madison researchers have designed a water-soluble chemical additive to improve bromide-based aqueous flow batteries. This innovation addresses critical challenges in energy storage, paving the way for safer and more cost-effective solutions.

“Bromide-based aqueous flow batteries are a promising solution, but there are many messy electrochemical problems with them. That’s why there’s no real successful bromide-based products today,” said Patrick Sullivan, a UW – Madison PhD graduate in chemistry. “Yet, our one additive can solve so many different problems.”

Sullivan, alongside PhD student Gyohun Choi and Assistant Professor Dawei Feng, engineered the additive to enhance battery performance and efficiency. The team’s findings were published in ‘Nature’ on October 23, 2024.

Aqueous Flow Batteries: A Safer Alternative

While lithium-ion batteries are widely used for grid-scale energy storage, their limitations include safety risks, such as fires and explosions, and reliance on a fragile international supply chain. By contrast, aqueous flow batteries, which use water-based electrolytes, offer scalability, sustainability, and improved safety.

The most established flow batteries rely on expensive and scarce vanadium ions. Bromide, a less costly and more abundant alternative, has similar theoretical performance potential. However, bromide-based batteries face practical obstacles. Bromide ions often escape through the membrane, lowering efficiency, or precipitate into an oily residue that disrupts functionality. Worse, the ions can form toxic bromine gas, raising safety concerns.

Solving Challenges with Molecular Engineering

To tackle these issues, Choi and the team developed over 500 molecular candidates, narrowing them to 13 engineered “soft-hard zwitterionic trappers.” These multifunctional additives proved highly effective in resolving bromide flow battery problems.

The additive encapsulates bromide ions, preventing them from passing through the membrane while maintaining their water solubility. It also stabilizes the ions, avoiding the formation of residue or harmful gases. The results have been remarkable. “Our devices with the additive functioned without decay for almost two months compared to ones without it, which typically fail within a day,” Feng explained.

This improvement significantly extends the operational life of the battery, a key factor for renewable energy storage systems designed for long-term use.

Looking Ahead

Choi plans to delve deeper into the science behind additives for halide flow batteries, while Sullivan, now CEO of renewable energy startup Flux XII, will work on scaling the additive for industrial applications. Early tests indicate the additive is viable for large-scale production.

The innovation marks an important step toward achieving reliable and affordable energy storage solutions, a critical component of the renewable energy future.

Research Report:Soft – hard zwitterionic additives for aqueous halide flow batteries

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Stability of perovskite solar cells boosted with innovative protective layer

by Clarence Oxford

Los Angeles CA (SPX) Nov 22, 2024

Scientists at Northwestern University have unveiled a new protective coating that dramatically improves the longevity of perovskite solar cells, a key step toward making these cells viable for real-world applications.

Perovskite solar cells offer greater efficiency and lower costs compared to traditional silicon-based cells. However, their lack of durability has historically hindered widespread adoption. Conventional coatings using ammonium-based compounds, while effective at enhancing efficiency, degrade quickly under environmental stresses such as heat and moisture.

To address this limitation, the research team introduced an amidinium-based protective layer, which outperformed ammonium coatings by a significant margin. Laboratory tests revealed that this innovative layer is 10 times more resistant to decomposition. Moreover, it tripled the cells’ T90 lifetime – the duration before a cell’s efficiency drops to 90% of its initial level under extreme conditions.

“The field has been working on the stability of perovskite solar cells for a long time,” said Bin Chen, a co-leader of the study. “So far, most reports focus on improving the stability of the perovskite material itself, overlooking the protective layers. By improving the protective layer, we were able to enhance the solar cells’ overall performance.”

Published in ‘Science’, the study marks a critical advancement in perovskite solar cell technology.

“This work addresses one of the critical barriers to widespread adoption of perovskite solar cells – stability under real-world conditions,” explained Mercouri Kanatzidis, another study co-leader. “By chemically reinforcing the protective layers, we’ve significantly advanced the durability of these cells without compromising their exceptional efficiency, bringing us closer to a practical, low-cost alternative to silicon-based photovoltaics.”

Bridging the Durability Gap

Although silicon remains the most widely used material for solar cells due to its reliability and durability, it is costly to produce and nearing its maximum efficiency potential. Researchers have turned to perovskites as a more affordable, higher-efficiency alternative. However, perovskite’s limited lifespan under sunlight, temperature fluctuations, and moisture has remained a major challenge.

The Northwestern team tackled this issue by using amidinium ligands, stable molecules capable of interacting with perovskites to enhance protection and prevent defects. Compared to ammonium-based molecules, amidinium compounds are more structurally resilient under harsh conditions.

“State-of-the-art perovskite solar cells typically have ammonium ligands as a passivation layer,” said Yi Yang, the study’s first author. “But ammonium tends to break down under thermal stress. We did some chemistry to convert the unstable ammonium into a more stable amidinium.”

This transformation, achieved through a chemical process called amidination, replaced the ammonium group with amidinium, preventing degradation and improving thermal stability.

Record-Setting Performance

With this innovation, the perovskite solar cells achieved an efficiency of 26.3%, converting 26.3% of sunlight into usable electricity. Additionally, the amidinium-coated cells maintained 90% of their initial efficiency after 1,100 hours of rigorous testing under heat and light, demonstrating their vastly improved durability.

These results build on previous advancements from Northwestern’s research team. Over the past two years, the Sargent lab has achieved record-breaking energy efficiency, introduced inverted perovskite structures, and incorporated liquid crystals to enhance cell performance.

“Perovskite-based solar cells have the potential to contribute to the decarbonization of the electricity supply once we finalize their design, achieve the union of performance and durability, and scale the devices,” said Ted Sargent, co-leader of the study. “The primary barrier to the commercialization of perovskite solar cells is their long-term stability. But due to its multi-decade head start, silicon still has an advantage in some areas, including stability. We are working to close that gap.”

The study supports the Trienens Institute’s Generate pillar, which focuses on advancing solar energy production through innovative technologies. By improving perovskite solar cells, Northwestern aims to develop the next generation of efficient, cost-effective solar solutions.

Research Report:Amidination of ligands for chemical and field-effect passivation stabilizes perovskite solar cells

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