{"id":8898,"date":"2023-01-04T08:52:09","date_gmt":"2023-01-04T14:52:09","guid":{"rendered":"https:\/\/www.wisconsin.edu\/all-in-wisconsin-new\/?post_type=campus_story&p=8898"},"modified":"2023-01-04T08:52:09","modified_gmt":"2023-01-04T14:52:09","slug":"high-impact-uw-stout-assistant-professor-helps-unlock-a-key-to-energy-efficient-skyscrapers","status":"publish","type":"campus_story","link":"https:\/\/www.wisconsin.edu\/all-in-wisconsin\/story\/high-impact-uw-stout-assistant-professor-helps-unlock-a-key-to-energy-efficient-skyscrapers\/","title":{"rendered":"High impact: UW-Stout assistant professor helps unlock a key to energy-efficient skyscrapers"},"content":{"rendered":"
\"Photo<\/a>
Using photovoltaic windows could make skyscrapers much more energy-efficient, according to a new national study co-authored by UW-Stout Assistant Professor Vincent Wheeler. \/ National Renewable Energy Laboratory, Dennis Schroeder<\/figcaption><\/figure>\n

Use of photovoltaic windows could significantly cut energy use and CO2 emissions, national lab study finds<\/h2>\n

Skyscrapers dominate city skylines, but these massive glass-walled structures can be made more energy efficient through the addition of thermally efficient photovoltaic \u2014 PV \u2014 windows, according to an analysis by researchers at the U.S. Department of Energy\u2019s National Renewable Energy Laboratory.<\/p>\n

Their findings, published in the journal\u00a0One Earth, outline building design rules that can yield a structure with net-zero or even net-positive energy consumption.<\/p>\n

\u201cThere are preconceived notions of what an energy-efficient building looks like, and it usually is not highly glazed, and it probably isn\u2019t very tall,\u201d said Lance Wheeler, a scientist at NREL who specializes in integrating PV technology into windows. \u201cWe found that there are other ways to build high-efficiency buildings.\u201d<\/p>\n

\"Photo<\/a>
Study co-authors are UW-Stout\u2019s Vincent Wheeler, engineering professor, left, and his twin brother, Lance, who works at the National Renewable Energy Laboratory. \/ Contributed photo<\/figcaption><\/figure>\n

Wheeler is co-author of the new paper, \u201cPhotovoltaic windows cut energy use and CO2\u00a0emissions by 40% in highly glazed buildings<\/a>,\u201d which he wrote with his twin brother, Vincent, an assistant professor at UW-Stout.<\/p>\n

Vincent Wheeler, in UW-Stout\u2019s department of engineering and technology, is director of the mechanical engineering program, part of the\u00a0Robert F. Cervenka School of Engineering<\/a>. He has a Ph.D. in mechanical engineering from the University of Minnesota.<\/p>\n

\u201cIt is not obvious that replacing ordinary windows with ones that improve the thermal performance and adds PV generation to a building in New York City can add as much benefit as doing so in sunny Tucson, but that is exactly what we found,\u201d Vincent Wheeler said of the research.<\/p>\n

To conduct the analysis, the brothers developed a software called\u00a0PVwindow\u00a0<\/a>that allows users to model the design of PV windows for building simulations.<\/p>\n

The other co-authors, all from NREL, are Janghyun Kim, Tom Daligault, Bryan Rosales, Chaiwat Engtrakul, and Robert Tenent.<\/p>\n

Buildings account for more than a third of the world\u2019s energy consumption and almost as much of global carbon dioxide emissions. But by combining PV with high thermal performance window technologies, new buildings can become a critical tool in combating climate change, the researchers noted.<\/p>\n

Modern office buildings stand out for their looming glass facades, a counterpoint to the days when they were constructed of concrete and single-pane windows. The Equitable Building in New York, for example, has a window-to-wall ratio of 25%. By comparison, the city\u2019s Bank of America Tower opened in 2016, 101 years later, with a ratio of 71%.<\/p>\n

The researchers considered buildings with a window-to-wall ratio of 95% \u2014 dubbed \u201chighly glazed\u201d \u2014 for most of their analysis to clearly illustrate the impact glazing has on building energy performance. Improvements in glazing technologies such as triple-pane windows helped improve the energy efficiency of buildings but so far have not been widely adopted.<\/p>\n

\u201cI don’t want to sit here and say we should be building highly glazed buildings,\u201d Lance Wheeler said. \u201cWe should be building highly efficient buildings. But if we if we choose to keep making these buildings, we\u2019ve got to reconcile their lower performance somehow, and PV windows are one way to do that.\u201d<\/p>\n

The researchers simulated the impact of three different types of PV glazing technologies, including\u00a0NREL\u2019s switchable PV technology<\/a>. Different glazing technologies were implemented in a building in eight cities, each in different climates. In addition to PVwindow, the researchers also relied on EnergyPlus and OpenStudio software platforms.<\/p>\n

With so many windows and sunlight streaming through, highly glazed buildings must expend considerable energy to cool the occupants. PV windows provide thermal insulation for a building and use the absorbed energy to generate electricity. Over the course of a year, the researchers found a clear trend in PV generations in climates with weather that changes strongly with the season.<\/p>\n

The simulations revealed that in Denver, for example, on-site PV generation can cut in half the day-averaged building electricity load for a heavily glazed 12-story structure. They also determined PV windows in Denver could eliminate 2 million kilograms of carbon dioxide emissions annually.<\/p>\n

The simulations showed a step-like increase in performance for each of the three different versions of PV glazing studied and demonstrated reduced energy consumption and carbon dioxide emissions in the eight climate zones.<\/p>\n

The researchers found energy use climbs when a building has more windows than wall space. However, the energy use drops when the ratio is increased and includes PV glazing. Indeed, larger floor-to-floor height coupled with PV glazing reduces building energy use. Couple the PV glazing with photovoltaic panels on the outside of the building \u2014 particularly facing east and west to capture early morning and late-day sun \u2014 and this skyscraper can reach net zero.<\/p>\n

\u201cPicture a skyline in, like, New York City where there are these high-rise buildings that are entirely glass,\u201d Lance Wheeler said. \u201cThey’re fully glazed. The Freedom Tower has millions of square feet of glass. It could be a power plant in itself.\u201d<\/p>\n

PV glazing could be paired with rooftop solar to increase the amount of electricity generated, with the potential to create more power than a building needs by using high-efficiency PV windows and unique building geometry, the researchers noted. The transition could address climate changing goals without sacrificing the architectural freedom of highly glazed facades.<\/p>\n

The U.S. Department of Energy\u2019s Building Technologies Office funded the research.<\/p>\n

\n

News release provided by National Renewable Energy Laboratory<\/em><\/p>\n

Link to story: https:\/\/www.uwstout.edu\/about-us\/news-center\/high-impact-assistant-professor-wheeler-helps-unlock-key-energy-efficient-skyscrapers<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Use of photovoltaic windows could significantly cut energy use and CO2 emissions, national lab study finds Skyscrapers dominate city skylines, but these massive glass-walled structures can be made more energy efficient through the addition of thermally efficient photovoltaic \u2014 PV \u2014 windows, according to an analysis by researchers at the U.S. Department of Energy\u2019s National […]<\/p>\n","protected":false},"author":15,"featured_media":8900,"comment_status":"closed","ping_status":"closed","template":"","institution":[90],"story_category":[],"class_list":["post-8898","campus_story","type-campus_story","status-publish","has-post-thumbnail","hentry","institution-uw-stout"],"_links":{"self":[{"href":"https:\/\/www.wisconsin.edu\/all-in-wisconsin\/wp-json\/wp\/v2\/campus_story\/8898","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wisconsin.edu\/all-in-wisconsin\/wp-json\/wp\/v2\/campus_story"}],"about":[{"href":"https:\/\/www.wisconsin.edu\/all-in-wisconsin\/wp-json\/wp\/v2\/types\/campus_story"}],"author":[{"embeddable":true,"href":"https:\/\/www.wisconsin.edu\/all-in-wisconsin\/wp-json\/wp\/v2\/users\/15"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wisconsin.edu\/all-in-wisconsin\/wp-json\/wp\/v2\/comments?post=8898"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.wisconsin.edu\/all-in-wisconsin\/wp-json\/wp\/v2\/media\/8900"}],"wp:attachment":[{"href":"https:\/\/www.wisconsin.edu\/all-in-wisconsin\/wp-json\/wp\/v2\/media?parent=8898"}],"wp:term":[{"taxonomy":"institution","embeddable":true,"href":"https:\/\/www.wisconsin.edu\/all-in-wisconsin\/wp-json\/wp\/v2\/institution?post=8898"},{"taxonomy":"story_category","embeddable":true,"href":"https:\/\/www.wisconsin.edu\/all-in-wisconsin\/wp-json\/wp\/v2\/story_category?post=8898"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}