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The United States has 121 million ha of marginal land that could be used to produce renewable energy. Approximately 1.73 million ha of this land includes federally funded brownfields, closed landfills, and abandoned mine lands. This study presents a GIS model to evaluate a range of site-specific energy production potentials on brownfields, closed landfills, and abandoned mine lands. Five energy sources are considered: soybeans, sunflowers, and algae for biodiesel, and solar and wind for electricity. Using soybeans, sunflowers, and algae, the United States could produce 39.9×10 3 TJ–59.1×10 3 TJ of renewable fuel per year from biodiesel. Using solar and wind resources, the United States could produce 114–53 TW h per year of electricity. The lower end of the range for each resource represents marginal yields as expected under marginal conditions. The upper end of the range represents prime conditions and is used for comparison to other, more productive types of land and U.S. regional climates. While renewable energy sources sited on individual sites may produce marginal amounts of energy, strategic uses of land and combinations of sources can supplement the national energy matrix. The five renewable energy sources examined in this study could meet up to 39% of the total U.S. 2013 energy demand for biofuel and electricity. [ABSTRACT FROM AUTHOR]

Abstract: To meet rising energy demands in a sustainable manner, the United States Renewable Fuel Standard 2 (RFS2) mandates the production of 3.78billion L (1billion gallons) of biomass-based biodiesel per year by 2020. Urban marginal lands, herein defined as lots with poor agricultural potential and unfit for residential purposes, can be used to cultivate biodiesel feedstock, which can contribute toward the RFS2. GIS is particularly well suited to identify the amount and location of these urban marginal lands. Biofuel crop production is one way for urban neighborhoods to reclaim vacant, blighted properties and also generate green energy for consumption. Combining soil classification data with urban development data, a GIS framework was developed to determine the amount of urban marginal land available in Pittsburgh, Pennsylvania. This location was chosen because small-scale sunflower crops are already being grown on urban marginal lands for biodiesel production. This paper evaluates two methods for identifying marginal lands for biofuel cultivation. The first is based on NRCS soil classifications derived from previous literature approaches. When compared with the locations of a nonprofit that is actually cultivating marginal lands, the NRCS soil classification method captures less than 35% of the marginal lands being cultivated in Pittsburgh, and 2400ha (6000acres) of marginal land in total that could be used to grow sunflowers for biodiesel production. We modify the NRCS marginal soil classification method to include certain types of urban commercial lands and lands not currently classified as marginal, and create a framework that identifies almost 90% of the marginal lands currently under cultivation in Pittsburgh, with approximately 3500ha (8700 acres) of available marginal lands. Pittsburgh’s marginal lands could be used to produce up to 129,000L (34,100gallons) of sunflower-based biodiesel. This could contribute a maximum of 0.1% to Pennsylvania’s biofuel mandate and 0.003% to the RFS2. While a city’s individual contribution may be incremental on the national scale, multiple cities and regions may be able to contribute to the RFS2. In addition, there is an unquantified social benefit that results from community engagement and revitalization, which is part of the mission of the Pittsburgh nonprofit. [Copyright &y& Elsevier]

Highlights • CDDPath provides CDD disposition estimates that complement generation estimates. • The CDDPath method combines waste characterization estimates with US state and industry data. • ∼140 MMT of CDD materials were estimated to go to landfill in 2014. • ∼400 MMT of CDD materials were estimated to be recovered for further use in 2014. Abstract National generation estimates for seven material types in the construction and demolition debris stream are regularly published in the United States. However, the quantities of these materials in different end-of-life management pathways are not published or otherwise made available. Quantification of end-of-life management pathways is useful for identifying approaches to decrease disposal and increase material recovery. An issue for construction and demolition debris is that data needed for a nationwide estimate of management pathways are not tracked in a single system. We propose and outline a method that draws on a combination of data sources, including nationwide generation estimates, state data, industry association data, and recovery facility reports. Capturing the available data and using the proposed method, we can estimate what end-of-life pathways are used for the seven materials in the US Environmental Protection Agency's annual reports of CDD generation (steel, wood products, drywall and plaster, brick and clay tile, asphalt shingles, concrete and asphalt concrete), and five additional materials managed within the CDD waste stream (carpet, plastic, glass, cardboard and organics). Method results indicate that the vast majority of CDD concrete and asphalt pavement, which in 2014 constituted ∼78% of the overall mass of the stream's components, were reclaimed for use, primarily in road projects. A significant opportunity for material recovery still exists for the remaining ∼22% of the stream. In 2014, approximately 64% of these remaining materials in the US was ultimately routed for landfill disposal. [ABSTRACT FROM AUTHOR]