The Role of Renewable Energy in the Promotion of Circular Urban Metabolism

TLDR

Cities consume vast materials and energy, generating significant waste and greenhouse gas emissions, and with projected 80 % population growth by mid‑21st century, the current fossil‑fuel‑based energy model threatens sustainability. The study seeks to determine how renewable energy can guide urban planning to satisfy cities’ energy demands. The authors review eleven renewable technologies of varying maturity that could reduce energy imports and shift urban metabolism from linear to circular. The study finds that the feasibility of these renewable options depends on resource availability, cost, policy, and community acceptance.

Abstract

Cities are human creations requiring large amounts of materials and energy. Constant consumption of resources exerts pressure on the environment not only due to its exploitation, but also because once processed, the resources produce waste, emissions or effluents. Cities are responsible for more than three quarters of the emissions of greenhouse gases. It is anticipated that the urban population will increase by up to 80% by the mid-21st century, which will make the current energy model unsustainable, as it is based on the intensive use of fossil resources. A change in urban planning is required to meet the energy requirements of cities. Several studies mention that renewable energy must be used in cities, but they do not identify the resources and technologies that can be used to promote circular urban metabolism. A review of the literature establishes that there are eleven renewable technologies with different degrees of maturity that could reduce the import of energy resources, which would contribute to changing the metabolic linear model into a circular model. However, the applicability of the different possibilities is conditional upon the availability of resources, costs, policies and community acceptance.