A new energy-efficient approach to building occupancy detection, a better way to detect heat loss in electric-vehicle batteries and a high-efficiency silicon solar cell—all developed or advanced at the U.S. Dept. of Energy (DOE)’s National Renewable Energy Laboratory (NREL)—have been named among this year’s most significant innovations by R&D Magazine.
"These R&D 100 awards honoring our work in solar, vehicles and energy efficiency demonstrate how NREL research produces results that can be moved to the marketplace,” NREL Dir. Dan Arvizu said. “Investments in energy research and development create jobs in America while also advancing the goal of a clean energy future.”
The three prestigious awards, known in the R&D community as “the Oscars of Innovation,” bring to 55 the number of R&D 100 awards that NREL has won since 1982.
IPOS adds eyes and brain to occupancy detection
NREL’s Image Processing Occupancy Sensor (IPOS) hangs from ceilings in office buildings and retail stores, combining an inexpensive camera with computer vision algorithms that can recognize the presence of human occupants. It’s the first fundamental change in occupancy detection in decades, adding optics to what had been merely motion detection.
IPOS can detect with greater accuracy the number of people in an area, spots where there are no people, the level of illuminance and other variables.
"People have been playing with using image processing for occupancy detection for quite a while," said NREL Senior Engineer Larry Brackney, who developed IPOS with NREL colleague Luigi Gentile Polese. "What's novel about IPOS is that it's not just an occupancy sensor. It combines a lot of capabilities—occupancy detection and classification; how many people are in the space; are they sitting still or moving around? It offers the potential of putting light or ventilation only where it's needed. All functions are combined in a single sensor, and it's done in a way that is more robust than current sensor technology."
In an office environment, IPOS can detect if there are people staying late, no matter how still they're sitting, and deliver that information so the building uses just the lights that are needed—no more, no less. The information can also be used to make instantaneous decisions on the amount of ventilation, air conditioning or daylighting the occupants of the office need at that particular moment. And it can signal when security officers should be alerted. IPOS raises the accuracy of occupancy detection from about 75% to the upper 90% range—and that converts directly to energy savings.
NREL’s IPOS team included Luigi Gentile Polese, Larry Brackney and Alex Swindler.
IBC measures heat to design longer-lasting, safer batteries
Isothermal Battery Calorimeters (IBCs) developed by NREL and NETZSCH come to market following a 70% year-over-year jump in sales of hybrid-electric and plug-in vehicles.
These IBCs are the only calorimeters in the world capable of performing the precise thermal measurements needed to make safer, longer-lasting and more cost-effective lithium-ion batteries.
“The IBC allows for the development of new thermal management techniques and strategies to ensure that the batteries in plug-in vehicles meet their warranty specifications and provide the needed power during their life. The IBC is positioning manufacturers to successfully introduce advanced vehicles into the U.S. marketplace,” said Senior Engineer Matt Keyser, who originally conceptualized IBCs with NREL colleague Ahmad Pesaran.
The IBCs’ patent-pending innovations—complete thermal isolation, the ability to test large cells and batteries and the features needed to test high energetic batteries safely—provide a level of accuracy and functionality not seen in other calorimeters. Precisely measuring heat generation helps optimize battery thermal-management systems to extend battery life and improve safety at an affordable cost. With forecasts of more than half a million hybrid and electric cars this year—and with manufacturers needing to meet increased fuel efficiency requirements—the IBCs allow auto manufacturers to address safety and efficiency issues long before drivers have to rely on the battery packs to get them home safely.
NREL’s Isothermal Battery Calorimeters team included Matt Keyser, Ahmad Pesaran, John Ireland, Dirk Long and Mark Mihalic. The NETZSCH team included Peter Ralbovsky, Jean-Francois Mauger and Gilles Widawski.
TetraSun’s high-efficiency, cost-effective monocrystalline solar cells
TetraSun, now a division of First Solar Inc., has developed an innovative cell architecture and manufacturing process with the potential to break the historical tie between high-efficiency and high-cost photovoltaic energy generation and represents an important step toward economically and environmentally compelling alternatives to fossil fuel-based energy production.
Relative to conventional crystalline solar cells, TetraSun's proprietary architecture allows for a greater percentage of incoming sunlight to be converted to electricity. Additionally, the company has reduced the typical manufacturing cost of high-efficiency solar cells with a more streamlined, simplified process flow and the elimination of certain costly materials. For instance, TetraSun's metallization process replaces silver, a high-cost commodity used in traditional screen printed solar cells, with copper, which is much lower cost and subject to less market-based price volatility.
“There has been tremendous focus on improving cell efficiency and cost in the solar industry. Often, technical advancements that offer efficiency improvements are significantly more complex and costly to manufacture while innovations that serve to reduce cost result in marginal improvements to efficiency,” said NREL Senior Project Manager Harin Ullal. “TetraSun's technology is special because it offers improvements in both performance and production cost at the same time.”
NREL performed characterization and reliability measurements on modules manufactured with TetraSun cells and collaborated with the company’s technical team to develop and implement modifications to the measured modules, contributing to improved product performance and reliability.
Leading the team for TetraSun were: Oliver Schultz-Wittmann, Denis DeCeuster, Adrian Turner and Doug Crafts. NREL’s team included Harin Ullal, Peter Hacke, Chunsheng Jiang, Richard Mitchell, Mowafak Al-Jassim and Martha Symko-Davies.