Rooftop PV Potential Determined by Backward Ray Tracing

A Case Study for the German Regions of Berlin, Cologne, and Hanover

authored by

Marlon Schlemminger, Dennis Bredemeier, Alexander Mahner, Raphael Niepelt, Michael H Breitner, Rolf Brendel

Abstract

Photovoltaics (PV) on building rooftops is a major contributor to the decarbonization of energy systems. We simulate the PV energy yield potential for 2.5 million individual roofs in three German regions. We cumulate the results for each single roof to calculate the cost-potential curves for the three cities Berlin, Cologne, and Hanover. These curves give the amount of electricity that can be generated at less than a given cost per kWh. We find that these curves have the shape of a hockey stick. Neglecting the dependence of PV investment on building size and thus on the system sizes causes largely different cost-potential curves that differ by 11%–18% for flat roofs due to their heterogeneous building size distribution. The cost-potential curves of the three cities are very similar when appropriately normalized, for example, by the local solar irradiation and the settlement area of the city, despite substantial variations in population density. This allows for an extrapolation of our results. For Germany, we reveal an upper limit for the total electricity generation from rooftop PV of 762 TWh/a with cost as low as 6.9 ct/kWh without accounting for area losses due to chimneys, air conditioning systems, and so forth. We estimate the actual potential to be at least half of that figure.

Organisation(s)

Solar Energy Section
Faculty of Mathematics and Physics
Institute of Computer Science for Business Administration

External Organisation(s)

Institute for Solar Energy Research (ISFH)

Type

Article

Journal

Progress in Photovoltaics: Research and Applications

Volume

32

Pages

912-929

ISSN

1062-7995

Publication date

11.2024

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials, Renewable Energy, Sustainability and the Environment, Condensed Matter Physics, Electrical and Electronic Engineering

Sustainable Development Goals

SDG 7 - Affordable and Clean Energy

Electronic version(s)

https://doi.org/10.1002/pip.3844 (Access: Open)