This new ARPA-E project has its roots in a collaborative endeavor of Berkeley Lab researchers working across divisions to seek out new approaches to improve building energy efficiency. Milliron’s group previously worked with EETD scientists and ARPA-E co-PIs Stephen Selkowitz and Arman Shehabi to discover that nanocrystal films can selectively modulate the transmittance of NIR while maintaining visible transparency and to analyze the energy savings potential of such spectrally selective electrochromic coatings if deployed across the US.

This new optical effect relies on the changes induced in the nanocrystals’ plasmonic properties upon the application of a small jolt of electricity. Now this team will work together to improve the performance of these materials and demonstrate scalable methods for manufacturing window coatings based on this principle.

“In addition to improving coating functionality, our technology utilizes a solution processing technique that will transfer well to large scale manufacturing. This makes commercial production practical and window cost affordable,” says Guillermo Garcia Chief Technology Officer and co-founder of Heliotrope Technologies, a start-up company working with Berkeley Lab to develop the dynamic window coatings.

“The ARPA-E initiative is a unique, highly competitive funding opportunity that allows for exploration of truly groundbreaking innovations,” says Molecular Foundry Director Omar Yaghi. “It is a pleasure to see yet another example of how the Foundry is successfully threading scientists and users with innovative ideas and research.”

The second ARPA-E grant of $1.9 million is for the “Automated Modeling and Simulation of Existing Buildings for Energy Efficiency” project led by Berkeley Lab’s Philip Haves. Haves, leader of EETD’s Simulation Research Group, will lead a project to develop the sensing and computer hardware for generating physical and thermal maps of the interiors of buildings. The goal is to reduce the energy consumption of existing commercial buildings through computer simulation of building energy use.

 “To do this, and do it in a lot of buildings, we need better, cheaper, faster ways to generate computer models of the buildings we want to improve,” says Haves.  He and his team plan to produce three-dimensional indoor maps of buildings using cameras and laser scanners, transferring this data to building simulation software.

The cameras and scanners will be mounted on a backpack; a person wearing the instrument package will walk through the rooms in the building to make a video of the building’s interior and exterior. A computer will then turn this video into a digital model of the building.

The computer simulations will allow building architects and engineers to design more energy-efficient buildings. Building simulations can help increase energy efficiency by identifying how a building is failing and what maintenance staff can do to tune up its energy-consuming systems, suggesting equipment upgrades for better energy performance, and ensuring that improvements are installed correctly and are delivering the expected energy savings.

Berkeley Lab’s team is collaborating with UC Berkeley Professor Avideh Zakhor, who leads the Video and Image Processing Lab in the Electrical Engineering and Computer Science Department, and Oliver Baumann of Ebert & Baumann Consulting Engineers in DC. The image processing techniques and the prototype backpack have been developed by Zakhor’s group.

Haves believes this technology can reduce the cost of building simulation by 30 to 40 percent, as well as the time it takes to develop a building model.