Renewable and Sustainable Energy Institute (RASEI)

Reducing our carbon emissions is necessary, but increasingly the science and engineering community are concluding that at current rates, it will not be enough on its own. At 428 parts per million and still rising, atmosphere CO2 will likely need to be actively removed, not just stopped at the source.

Such is the understood urgency of the problem, facilities designed to do exactly that are already under construction, the largest of which is in Texas, which is designed to pull ~500,00 tonnes of CO2 out of the atmosphere every year. This plant will be using an alkaline liquid that chemically binds the CO2 as it passes through. The basic principle works, and has been known for many years, but the detailed chemistry of how the process works, in the thin zone where air and liquid meet, is poorly understood. It is something of a black box; we know what goes in, we can measure what comes out, but we don’t really know what happens.

This means that there are real significant opportunities for optimization; even modest improvements in efficiency could translate to substantial reductions in cost and energy use. First, we need to get a clear picture of what is happening inside the black box.

Before you can optimize something, you have to be able to measure it. A team led by RASEI Fellow Wilson Smith worked through more than 70 design, print, and test iterations to build a bespoke flow cell that enabled them to watch the chemistry happening inside the ‘black box’ in real time. Think of it like medicine before medical imaging, you can understand a lot without being able to see inside, but the moment you can, everything changes.

Find out more about the process, what the team learned, and how they developed tools for future designs of carbon capture flow cells in our highlight article here:

Watching Carbon Capture in Action May 2026

To capture carbon from the environment, we need to first decarbonize the grid

In 2024, for the first time on record, global average temperatures exceeded 1.5 °C above pre-industrial levels. This was the threshold scientists have long flagged as a critical limit. It is a signal that cutting emissions, while essential, won't be enough on its own. We are going to need to actively remove carbon from the atmosphere as well.

New research from RASEI takes a practical look at what that actually involves, the science, the costs, the trade-offs, and the conditions that determine its feasibility.

One headline finding from this study is that carbon capture technologies that run on electricity are only as effective as the gri powering them. Plug into a fossil-heavy grid, and a significant portion of what you capture gets cancelled out by the emissions used to run the process. Decarbonizing our electricity supply isn't a separate problem, it is a pre-requisite for carbon capture.

Check out our highlight on this article, where we speak to the authors about the factors that influence this important technology:

https://www.colorado.edu/rasei/2026/05/14/capture-carbon-atmosphere-we-need-first-decarbonize-grid

While the underlying physics states that the same device can operate as a solar cell and an LED, challenges with the device architecture have prevented it from being achieved, until now.

A team led by RASEI Fellow Mike McGehee has now built a perovskite diode that does both efficiently for the first time in this class of material.

The diode, built from metal-halide perovskites, held the world record for solar cell efficiency in its material class when the research was submitted for publication, converting 26.7% of incoming sunlight into electricity. Run in reverse, the same device emits light at around 31% efficiency, figures that would be considered very strong for a device designed to do only one of those things.

Across all solar cell materials, only single-crystal gallium arsenide has previously reached both thresholds, and that material is significantly more expensive and difficult to work with at manufacturing scales.

The practical implications are significant. This work points not only to applications in harvesting solar energy, but also more flexibility in how the material can be used. A display screen, for example, that could harvest ambient light when not in use.

The research was published in Joule. We had the opportunity to sit down with the authors and put together a highlight that discusses this researcher, check it out at the link below:

https://www.colorado.edu/rasei/2026/04/27/solar-cell-moonlights-led-and-does-both-better

Imagine looking at a city from a satellite. Everything looks orderly, almost symmetric. But walk into a neighborhood and you will find different architectures, different rules, and whole different characters.

Something similar happens inside magnetic materials. When researchers look at the overall structure of such materials they can appear perfectly balanced, which rule out the existence of some spin and charge transport effects.

But zoom in to the atomic, or neighborhood, scale, and a different picture emerges. Local regions can have their own asymmetry, and with it, their own spin and charge characteristics, influencing how charge and spin moves throughout the whole material.

Why is this important? Magnetic materials are crucial components of modern electronic and data storage devices. If we understand them better we can design more powerful and energy efficient computers and hard drives.

This new Perspective from the Zunger Group, published in Matter, organizes these local hidden effects into a clear framework. Understanding these effects, and being able to design with them, offers access to new, and more efficient and more affordable materials.

We put together a highlight of this work here:

The Physics That Hides in Plain Sight April 2026

What if the data center coming to your town could heat your home, stabilize the power grid, and reduce energy bills, instead of just raising them? RASEI Fellows Gregor Henze and Sean Shaheen, make the case that it's not only possible, but it is already happening in some places.

Check out their article in The Conversation US

Data centers don’t have to be a burden on local communities – and can even support them by generating power and repurposing waste heat Two engineers explain how data center design, construction and operation can help the facilities support their communities.

Today is CU Boulders 2026 Buffs All In Day! Today celebrates 150 years of giving that has supported CU Boulder, impacting communities and connections across Campus.

Check out some of the really excellent videos, messages, and highlights from how giving has impacted ideas, departments, and programs at the link below.

And of course, thank you to those who have already given to RASEI!

https://giveto.colorado.edu/buffs-all-in?utm_campaign=bai_26&utm_medium=email&utm_source=scu&utm_term=[rasei]

Interested in learning more about a career in Renewable Energy? RASEI is co-hosting a panel discussion with Women of Renewable Industries and Sustainable Energy on Wednesday April 1 at 4:30 PM. Come and join the discussion to learn more careers across a range of different sectors.

https://calendar.colorado.edu/event/wrise-career-panel?utm_campaign=widget&utm_medium=widget&utm_source=University+of+Colorado+University of Colorado Boulder Family Programs

Careers in Renewable Energy Come and join the discussion with WRISE / RASEI Careers panel to find out more about the pathways and careers in renewable energy. Our panelists include: Claire Behar - Foss & CompanyJan Coyle - UlteigProf. Tanja Cuk - CU BoulderMelissa Funsten - TractDr. Nicola Mendoza - Sunforged SolutionsTerri Wa...

How do changes at the scale of individual atoms matter for real‑world materials?

This new article from RASEI highlights research on nanocrystals, where atoms can subtly shift positions. Studying these changes helps scientists learn how material properties emerge—and how future energy‑related technologies might benefit from that understanding.

This collaborative article includes two RASEI Fellows, Gordana Dukovic and Sadegh Yazdi, and spans not one, but actually two large collaborative networks. The NSF Science and Technology Centers STROBE and IMOD brought together the expertise needed to solve these challenges.

Read the story:
https://www.colorado.edu/rasei/2026/03/17/atomic-musical-chairs-how-tiny-nanocrystals-are-informing-future-energy-efficient

Coming up on Wednesday April 1, RASEI is cohosting a panel discussion on careers in renewable energy with Women of Renewable Industries and Sustainable Energy. Come and join the discussion in the SEEC building from 4:30 - 6:00 PM

https://calendar.colorado.edu/event/wrise-career-panel?utm_campaign=widget&utm_medium=widget&utm_source=University+of+Colorado+Boulder

Graduate student Ben Hammel, a member of RASEI Fellow Gordana Dukovic’s research group was one of eleven finalists in the CU Boulder Three Minute Thesis competition last month. Find out more about his experience making nanocrystals understandable here: https://www.colorado.edu/rasei/2026/02/24/2026-three-minute-thesis-finalists