While we all understand the functionality of paved expanses for transport and parking, hot pavements create huge amounts of heat, that can significantly alter urban and suburban environments. Now a team from University of Texas at San Antonio has received funding to help generate power from hot pavements.
The group, led by Samer Dessouky, professor of civil and environmental engineering at The University of Texas at San Antonio, was awarded $298,000 through the strategic alliance between the Texas Sustainable Energy Research Institute and CPS Energy.
Dessouky will use the funding to improve a technology he developed with his team that converts heat from paved surfaces into electricity. This technology allows paved areas, such as freeways, airport runways and parking lots to generate electricity, which can be used in rural areas for powering signage and data collection systems independently of the electric grid.
In 2016, Dessouky and his team began developing a thermal energy-harvesting system. They tested this system by installing several prototypes near the Concrete Laboratory on the west side of the UTSA Main Campus. In their system, power was harvested from the temperature differential between the surface of the pavement and the lower temperature deeper into the soil. The project, supported by CPS Energy, allows his team to fine tune the way the system works.
A paper submitted to the Transportation Research Board in 2017 explained the technology in more detail. “The thermal gradient between the surface temperature and the pavement substrata can be used to generate electrical power through thermoelectric generators (TEGs). The proposed prototype collects heat from the pavement surface and transfers it to a TEG embedded into the subgrade at the edge of the pavement shoulder. Early results suggest that the TEG prototype, measuring 64x64mm, is capable of generating an average of 10 mWatt of electric power over a period of 8 hours for weather conditions in Southern Texas. Scaling up the prototype using multiple TEG units could generate sufficient electricity to sustainably power low-watt LED lights and roadway/traffic sensors at offgrid remote areas.”
Dessouky is now utilizing drones to fly across large landscapes like airports and universities to map out where heat is most concentrated. This aids the researchers in pinpointing the best places to implement the technology.
“Since airports consist of large areas of concrete pavement, they’re ideal for this kind of technology,” Dessouky said. “In a blackout, this could be used as a back-up source of power for illuminating LED at runways and taxiways or could be used as the sole means of lighting rural civilian airport runways.”
Earlier this year Dessouky, his collaborator, A.T. Papagiannakis, McDermott Professor of Civil and Environmental Engineering, and their graduate student Utpal Datta, won first place in the Innovation Competition of the American Society of Civil Engineers and second place in the Airport Cooperative Research Program University Design Competition for the new technology.
Dessouky believes that the technology could also benefit uncongested, rural areas with few alternatives to power sources. He’s also looking at how it could benefit UTSA’s own campuses, which feature many green spaces in addition to concrete structures and several asphalt parking lots that can absorb a great amount of heat.