Four climate change-focused pilot projects report final outcomes

Sustainable metamaterials for insulation applications

Investigators
Eleftheria Roumeli, Materials Science & Engineering
Tomás Méndez Echenagucia, Architecture

Project summary
The project set out to pair biomatter-derived foam blocks with metamaterial architectures to yield low-carbon high-performance acoustic insulation. We (i) focused on understanding processing-structure-property relationships for Ulva-based foams and (ii) initiated finite-element (FEA) design of hybrid block/resonator assemblies.

Our experimental campaign began by selecting three green-seaweed feedstocks (Ulva ohnoi, U. lactuca and a wild Ulva sp.) and converting them into aqueous slurries at 5, 7.5 and 10 wt%. After ball-milling and ultrasonication, slurries were freeze-cast either by liquid-nitrogen quenching or conventional freezing. The rapid quench produced fibrillar cell walls and pore diameters roughly 6 to 20 times smaller than those formed by slow freezing whereas the slower route yielded sheet-like walls and lower bulk densities (0.002–0.024 g cm-3). SEM and micro-CT imaging confirmed these morphological distinctions and enabled a porosity-modulus analysis explaining the systematic rise in compressive strength (1–600 kPa) and modulus (0.03–14.1 MPa) with solids content and pore refinement.

Acoustic impedance-tube measurements demonstrated that most of our Ulva foams outperformed commercial polyester panels in the 0–2000 Hz band where most day-to-day noise is heard. The foam with most promising performance is 10 wt% foams of U. ohnoi and U. lactuca which achieved near-unity absorption at ~1.4 kHz. The impedance tube measurements were used to create a porous media FEA model using the Johnson-Champoux-Allard method. The resulting material model was used to create a hybrid porous and resonant acoustic absorber. The results show that the hybrid material can benefit from both acoustic absorption types showing the potential for efficient broadband sound absorption with limited use of space or emissions.

Impact and Future Directions

• Demonstrated that freeze-dried Ulva foams can meet or exceed commercial acoustic panels in the low- to mid-frequency range critical for occupant comfort.
• Generated the first quantitative LCA for algae-based insulation identifying processing energy as the primary hotspot and directing future scale-up research.
• The FEA–experimental loop provides a transferable tool for tailoring broadband absorbers from any biomatter feedstock.

Next Steps: We are finalizing a first manuscript for a high-impact materials science journal and expect to submit it in October 2025. A second paper centered on the metamaterial architecture will follow once the initial study is under review. These publications will position us to craft a strong data-driven research proposal immediately thereafter.

Wild food plant diversity, conservation, and community knowledge in the Eastern Mediterranean

Investigators
Danya Al-Saleh, Jackson School of International Studies
Jon Bakker, Environmental and Forest Sciences
Omar Tesdell, Birzeit University

Project summary
The overarching goal of this project was to carry out ex situ conservation of at least 10 key wild and native food plant species in Palestine with the Ardeea research group (link). Wild food plants have been and remain an important source of food for peoples of the region. Despite being the center of origin of wheat, barley, lentils and other major world crops, the vast majority of staple foods and feed for livestock are imported to Palestine from abroad. Climatic shifts threaten these wild foods in Palestine and throughout the Eastern Mediterranean region. Palestine has a wealth of native food plants and wild relatives of crops and knowledge about how they are used. This research team brought together expertise in plant ecology (Dr. Bakker), feminist methodology, climate justice and gender (Dr. Al-Saleh) and the geography of native plants and agriculture in the Eastern Mediterranean (Dr. Tesdell).

This work has contributed to the documentation of wild food plant use in the West Bank. Over the course of this project, the team focused on conservation through a combination of methods including collection of seeds from numerous species, seed storage and oral history interviews with keepers of knowledge about these species. The result of this project included ex situ conservation of 15 key wild and native food plant species from 10 target populations in Palestine’s hill region in the West Bank. The Ardeea research team conducted, transcribed, translated and coded over 40 interviews with farmers largely women about these species. This project also strengthened UW’s international engagement and facilitated the interchange of ideas about the production of native plants in Palestine and the Pacific Northwest. During February 2025, Dr Omar Tesdell visited the UW for a research talk and a week-long visit to campus that engaged faculty and students with interests in food sovereignty, the ethics of data collection, Indigenous knowledge and plant ecology. Regional conflict unfortunately prevented Drs. Al-Saleh and Bakker from visiting Palestine.

DecarbCityTwin: A Platform for Equitable Decarbonization of the Built Environment

Investigators
Narjes Abbasabadi, Architecture
Christopher Meek, Architecture
Kate Simonen, Architecture
Carrie Sturts Dossick, Construction Management
Daniel Kirschen, Electrical & Computer Engineering
Mehdi Ashayeri, Southern Illinois University
Lylianna Allala, City of Seattle’s Office of Sustainability & Environment
Ani Krishnan, City of Seattle’s Office of Sustainability & Environment

Project summary
DecarbCityTwin aims to facilitate building decarbonization while addressing energy, health and equity challenges particularly in marginalized communities. By integrating advanced physics-based and data-driven modeling with AI and machine learning and leveraging sensing technology, the project supports the monitoring, modeling and simulation of “what-if” scenarios to inform design, retrofit interventions, policy strategies and deepen community engagement.

This pilot phase achieved three major goals that form its foundation, encompassing three interconnected components. The first component focuses on air quality modeling, prediction, visualization and Virtual Reality (VR)-based immersive experiences. In this pilot project, we developed a novel AI-enhanced Land Use Regression (LUR) framework to predict fine particulate matter (PM₂.₅), a critical pollutant associated with severe health outcomes. The model was designed to capture PM₂.₅ variability across Seattle WA, leveraging machine learning and various data sources including socioeconomic factors, building urban infrastructure, environmental conditions, transportation networks and low-cost sensors. By incorporating advanced machine learning techniques, the model effectively captured complex non-linear relationships in urban air quality at a high spatial resolution of 30 × 30 meters, significantly improving the accuracy and robustness of PM₂.₅ predictions. Additionally, an immersive VR model was developed to visualize dynamic pollution patterns, offering actionable insights into daily air quality fluctuations. This interactive approach enhances accessibility and engagement, enabling community members to intuitively interpret complex data and simulation results.

The second component addresses building retrofits and decarbonization strategies. Machine learning-enhanced urban building energy modeling was developed to identify optimal health-driven retrofits. This pilot study focused on the Duwamish Valley neighborhoods—areas facing significant challenges related to energy inefficiency, air pollution and health disparities. Archetypal models were developed to represent common housing typologies (e.g. single-family homes, duplexes, quadplexes and small apartments) within the pilot community. Thousands of retrofit simulations were explored to enhance energy efficiency while simultaneously improving indoor air quality and occupant health.

The third component emphasizes community engagement and education. This aspect of the project aims to increase public awareness of air pollution and energy efficiency through participatory workshops. Two major community engagement initiatives were conducted: (1) an Earth Day event at Duwamish/Concord International Elementary School involving approximately 200 participants and (2) a focus group session at the Duwamish Hub with 20 participants representing local organizations, stakeholders and households. Findings from the project were featured through an educational module and through an immersive VR-based tool designed to help residents better understand pollution dynamics. The effectiveness of the DecarbCityTwin platform was assessed through pre- and post-experience surveys which revealed gains in knowledge, behavioral motivation and user engagement. These findings underscore the platform’s potential as a transformative tool for community empowerment, illustrating how digital solutions can be leveraged to address such critical challenges.

The results of this project contribute to a growing body of literature on air pollution prediction, energy efficiency and the role of digital tools in fostering health-driven and equitable decarbonization. This pilot project focused on Seattle WA with a particular emphasis on the Duwamish Valley neighborhoods, developed in collaboration with the City of Seattle’s Office of Sustainability and Environment and the Duwamish River Community Coalition (DRCC).

Assessing the Benefits of Community Photovoltaic Power Projects in Washington

Investigators
Dargan Frierson, Atmospheric Sciences
Josh Lawler, Environmental and Forest Sciences
Alyssa Poletti, Atmospheric Sciences
Eileen V. Quigley, Clean Energy Transition Institute
Ruby Moore-Bloom, Clean Energy Transition Institute

Project summary
We collaborated with the Clean Energy Transition Institute (CETI) on a study of community solar in Washington state. Community solar is defined as mid-sized solar arrays larger than a single household but smaller than 1 megawatt capacity that are distributed and aim to provide community benefit.

Our research culminated in the publication of an ArcGIS Storymap entitled The Sun Also Rises in Washington: Exploring Community-Scale Solar Power (available at https://storymaps.arcgis.com/stories/53ce8eb2b5d948ba9642f5870e195f30), published on December 2, 2025.

Our study began with a quantification of available solar radiation in Washington during different months, taking the commonly held assumption of ever-gray skies in our state: although winter generally lacks sunlight, summers are characterized by long daylight hours and clearer skies. Thus the available solar power is significantly higher in those months.

We next studied a range of existing community solar projects in the state using data from Washington State University’s Community Solar Expansion Program. We then performed interviews with a set of stakeholders around the state to get a variety of perspectives on how they view community solar and what research questions were most useful to study from their perspective. We depicted some of the installations that we learned about in the Storymap including installations at the Vashon Island United Methodist Church which features battery storage, Merritt Manor Community Solar in Olympia which provides benefits to low-income residents and Haystack Heights in Spokane, a novel co-housing development that has shared spaces to build community among residents. We additionally highlighted the recent community solar installations on the nation of the Spokane Tribe of Indians with their Children of the Sun Solar Initiative program. We also highlighted projects in Jefferson County which recently municipalized their power authority.

Based on the interviews with the stakeholders, we proposed two different lenses of benefits of community solar. First, from a renter’s perspective, community solar can have benefits by lowering the cost of electricity which is a particularly salient problem since rates have skyrocketed in recent years. While renters cannot themselves purchase solar panels, subscription-based models can allow renters to accrue these benefits. To support this lens, we created maps that showed the fraction of renters in each census tract across the state. More than 270,000 households in Washington are energy-burdened, spending over 6% of their income on home energy bills.

The second lens is based on resilience benefits. When connected to battery storage to create a microgrid, solar power can increase the resiliency of electricity since power is generated where it is used even without active connections to the larger electricity grid. With a rapidly changing climate causing increasing flooding events, heatwaves and other disturbances, increased resiliency will only become more important. For this lens, we studied data such as outage frequency across different counties in Washington, finding that the coastal counties are particularly plagued by outages. We also studied the number of residents that are dependent on home medical devices that need electricity as a measure of the need for consistency of electricity for life.

In summary, we found community solar to be important in creating a resilient affordable electricity system for Washington residents. Our Storymap was shared widely across CETI’s network and has generated a wide range of positive responses from recipients. The work was additionally presented by Ruby Moore-Bloom at the 2025 Washington State Solar Summit in October 2025.