In the heart of Spain, the city of Vitoria-Gasteiz is serving as a case study for a groundbreaking analysis that could reshape how cities approach renewable energy deployment. A recent study published in the journal ‘Frontiers in Sustainable Cities’ (or ‘Frontiers in Sustainable Urban Environments’ in English) delves into the material and social footprint of rooftop photovoltaics (RPVs), offering insights that could steer the energy sector towards a more sustainable and equitable future.
The research, led by Alex Tro-Cabrera from the EKOPOL—Research Group on Ecological Economics and Political Ecology at the University of the Basque Country UPV/EHU, examines the implications of RPVs in terms of primary extraction material requirements and environmental and social impacts. The study models the potential annual photovoltaic electricity production of 473 GWh for Vitoria-Gasteiz and compares it to the same amount of electricity produced by the conventional Spanish electricity mix.
One of the most striking findings is the high ratio of primary extraction requirements to reserves for certain materials. “We found a very high ratio of primary extraction requirements to reserves for gold (28.5%), silver (29.4%), and tin (56.2%),” Tro-Cabrera explains. This means that the deployment of RPVs could significantly strain global reserves of these materials. Additionally, the study reveals that RPV deployment would increase the in-use stocks of silver by 12%, and the aluminum and tin stocks by 9%.
The environmental benefits of RPVs are substantial, with significant reductions in climate change impact (79%), acidification (71%), land use (70%), and water use (63%). However, the social life cycle assessment shows no substantial changes in risk levels, as the economic activity in photovoltaic supply chains remains largely concentrated in developing countries, generating similar social impacts.
This research highlights the need for a balanced approach to renewable energy deployment. “By acknowledging the socio-environmental trade-offs of renewable energies, cities can foster a fair energy transition that is both materially grounded and ecologically aware,” Tro-Cabrera notes.
The findings have significant implications for the energy sector. As cities worldwide strive to meet their renewable energy targets, understanding the material and social footprints of RPVs is crucial. The study suggests that recycling activities should be more than doubled to avoid an increase in mining, and it underscores the need for a more equitable distribution of economic activity in the photovoltaic supply chains.
In the broader context of the polycrisis—encompassing climate change, resource depletion, and social inequality—the study offers a nuanced perspective on urban ecologies and material and social footprints. It calls for a more holistic approach to renewable energy deployment, one that considers not just the environmental benefits but also the material and social impacts.
As the energy sector grapples with these challenges, the research from Vitoria-Gasteiz serves as a beacon, guiding the way towards a more sustainable and equitable future. The study’s insights could shape future developments in the field, influencing policy decisions and commercial strategies alike. By embracing a more comprehensive understanding of the impacts of RPVs, cities can lead the way in fostering a fair energy transition that benefits both people and the planet.