Impacts of Rooftop Photovoltaics on the Urban Thermal Microclimate: Metrological Investigations

Ambitious climate protection requires decentralized renewable energy production via building-related photovoltaics in cities. However, cities are also subject to the Urban Heat Island effect, which negatively impacts human health. In this context, the installation of PV modules in urban areas raises...

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Main Authors: Elisabeth Fassbender, Simon Pytlik, Josef Rott, Claudia Hemmerle
Format: Article
Language:English
Published: MDPI AG 2023-09-01
Series:Buildings
Subjects:
Online Access:https://www.mdpi.com/2075-5309/13/9/2339
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author Elisabeth Fassbender
Simon Pytlik
Josef Rott
Claudia Hemmerle
author_facet Elisabeth Fassbender
Simon Pytlik
Josef Rott
Claudia Hemmerle
author_sort Elisabeth Fassbender
collection DOAJ
description Ambitious climate protection requires decentralized renewable energy production via building-related photovoltaics in cities. However, cities are also subject to the Urban Heat Island effect, which negatively impacts human health. In this context, the installation of PV modules in urban areas raises the question of how the energy-active building component affects its surrounding thermal microclimate. The topic is approached with a novel, twofold methodology: First, a horizontal ambient air temperature profile above a rooftop PV installation and the analysis of surface temperatures provide primal indications of the impacts of PV on the thermal microclimate. Secondly, establishing energy balances allows us to retrace the energy fluxes. The data required for the comparative analyses are gathered through metrological investigations of two rooftops with and without PVs in Munich, Germany. The results of the investigation show a daytime heating effect of photovoltaics on the ambient air temperature of up to +1.35 K and a nighttime cooling effect of up to −1.19 K. Cumulated daily, the daytime heating effect exceeds the impact of the nighttime cooling. The main driver of the heating and cooling is the additional convective heat transfer from the PV modules. However, the impacts of the PV modules are marginal and restricted to their direct surroundings.
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spelling doaj.art-36001b8d33b045b99e66abf72f6987002023-11-19T09:52:41ZengMDPI AGBuildings2075-53092023-09-01139233910.3390/buildings13092339Impacts of Rooftop Photovoltaics on the Urban Thermal Microclimate: Metrological InvestigationsElisabeth Fassbender0Simon Pytlik1Josef Rott2Claudia Hemmerle3Chair of Building Technology and Climate Responsive Design, School of Engineering and Design, Technical University of Munich, 80333 Munich, GermanyChair of Building Technology and Climate Responsive Design, School of Engineering and Design, Technical University of Munich, 80333 Munich, GermanyChair of Building Technology and Climate Responsive Design, School of Engineering and Design, Technical University of Munich, 80333 Munich, GermanyChair of Building Technology and Climate Responsive Design, School of Engineering and Design, Technical University of Munich, 80333 Munich, GermanyAmbitious climate protection requires decentralized renewable energy production via building-related photovoltaics in cities. However, cities are also subject to the Urban Heat Island effect, which negatively impacts human health. In this context, the installation of PV modules in urban areas raises the question of how the energy-active building component affects its surrounding thermal microclimate. The topic is approached with a novel, twofold methodology: First, a horizontal ambient air temperature profile above a rooftop PV installation and the analysis of surface temperatures provide primal indications of the impacts of PV on the thermal microclimate. Secondly, establishing energy balances allows us to retrace the energy fluxes. The data required for the comparative analyses are gathered through metrological investigations of two rooftops with and without PVs in Munich, Germany. The results of the investigation show a daytime heating effect of photovoltaics on the ambient air temperature of up to +1.35 K and a nighttime cooling effect of up to −1.19 K. Cumulated daily, the daytime heating effect exceeds the impact of the nighttime cooling. The main driver of the heating and cooling is the additional convective heat transfer from the PV modules. However, the impacts of the PV modules are marginal and restricted to their direct surroundings.https://www.mdpi.com/2075-5309/13/9/2339thermal microclimatephotovoltaicmeasurementsenergy balanceradiation balancetemperature profile
spellingShingle Elisabeth Fassbender
Simon Pytlik
Josef Rott
Claudia Hemmerle
Impacts of Rooftop Photovoltaics on the Urban Thermal Microclimate: Metrological Investigations
Buildings
thermal microclimate
photovoltaic
measurements
energy balance
radiation balance
temperature profile
title Impacts of Rooftop Photovoltaics on the Urban Thermal Microclimate: Metrological Investigations
title_full Impacts of Rooftop Photovoltaics on the Urban Thermal Microclimate: Metrological Investigations
title_fullStr Impacts of Rooftop Photovoltaics on the Urban Thermal Microclimate: Metrological Investigations
title_full_unstemmed Impacts of Rooftop Photovoltaics on the Urban Thermal Microclimate: Metrological Investigations
title_short Impacts of Rooftop Photovoltaics on the Urban Thermal Microclimate: Metrological Investigations
title_sort impacts of rooftop photovoltaics on the urban thermal microclimate metrological investigations
topic thermal microclimate
photovoltaic
measurements
energy balance
radiation balance
temperature profile
url https://www.mdpi.com/2075-5309/13/9/2339
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AT simonpytlik impactsofrooftopphotovoltaicsontheurbanthermalmicroclimatemetrologicalinvestigations
AT josefrott impactsofrooftopphotovoltaicsontheurbanthermalmicroclimatemetrologicalinvestigations
AT claudiahemmerle impactsofrooftopphotovoltaicsontheurbanthermalmicroclimatemetrologicalinvestigations