Can sustainability plans make sustainable cities? The ecological footprint implications of renewable energy within Philadelphia’sGreenworksPlan

Abstract

Municipal sustainability plans typically include laudable environmental goals, but they rarely explain the connection between these goals and a larger conception of sustainability. In this article, we examine one local sustainability plan, Philadelphia's Greenworks, through a city-based, rather than per capita-based, ecological footprint (EF) analysis. Our objective is to theoretically establish the extent to which at least one of the items in Greenworks-to have 20% of the city's electricity come from alternative energy sources-might reduce Philadelphia's overall energy footprint if implemented within the municipal boundaries. By moving away from the idea that per capita energy footprints add up to a citywide energy footprint, we posit that a city can reduce its overall energy footprint by utilizing internal resources, even if the total land used for that respective energy were to increase. For many cities this will result in the use of renewables, such as solar, biogas, wind, hydropower, geothermal, and other creative solutions. By extending at least one component of Philadelphia's sustainability plan through EF analysis, we provide a hypothetical example of how municipal sustainability goals might contribute to a larger goal of urban sustainability, at least in the limited sense that they become less reliant on outlying resources.

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

“…The study by Moscovici et al [55] appreciates the use of renewable energies based on a comparison of the ecological footprint (area required for the deployment of equipment and for their manufacture), and establishes that geothermal and hydropower energy are a more appropriate response to wind, solar and biomass. Barragán et al [56] state that photovoltaic, hydroelectric and biogas technologies from landfills are the most suitable technologies for the production of electric power in a city located in the Latin American Andes.…”

“…Under the UM approach, its implementation would be subject to the condition that the resource be within the city limits. Moscovici et al [55] suggest that for Philadelphia (USA), an alternative to enable sustainability and self-sufficiency is the construction of small hydroelectric stations within the city limits. Fujiia et al [71] find that the demand of up to 29,000 dwellings could be supplied if hydroelectric plants of less than 1000 kW are used, installed in the rivers that cross the city of Beppu (Japan).…”

“…• Self-provision decreases uncertainties in the energy supply due to externalities [42] and reduces large energy production and transport infrastructures [4,55]. It also allows reductions in the consumption of fossil fuels.…”

“…[131]. Energy supply efficiency is promoted because the losses associated with transport from long distances will decrease [55,103], and there will be a reduction in raw material consumption since it avoids losses by energy transformation [51]. In addition to the use of non-renewable resources (lower consumption of fossil resources), distributed energies are close to the points of consumption (increases energy efficiency), reducing energy dependence and increasing safety and reliability [93,127].…”

“…Since energy in the city is not expected to be produced in large power plants, an economy of scale related to huge production centers is not expected, in fact, this is an advantage of multi MW projects [103]. It is understood in this case that an economy of scale can be achieved with the possibility of expanding the manufacture and assembly of the renewables devices, which in the long run will cause a decrease in the equipment cost [55], encouraging its use and economic convenience.…”