A GIS Analysis of Commercial Food Waste and Anaerobic Digestion/Combined Heat and Power in Massachusetts

Abstract

This thesis examines a set of geospatial and economic factors bearing on the development of anaerobic digestion/combined heat and power (AD CHP) infrastructure in Massachusetts relative to the Commonwealth's renewable energy goals. The Clean Energy Results Program has set as a sustainability goal the development of AD CHP sufficient to bring total power output to 375 GWh/year (50 MW) by the year 2020. The availability of sites for facilities is a constraint on development, as is the financial risk posed by nearby organic waste processors. The primary research question to be evaluated is whether the geospatial and economic barriers to AD CHP are significant enough to prevent the attainment of the Commonwealth’s sustainability goal. My analyses will examine the following two hypotheses: 1) Constraints imposed by wetlands and floodplains, residential abutters, collection areas, and existing AD CHP facilities will not impede the development of AD CHP infrastructure, and 2) said infrastructure would be economically competitive with composting facilities.

A number of geographic information system models were constructed and used to rank potential sites over open landfills in Massachusetts. Multiple factors were included: wetlands or floodplains, residential abutters, commercial food waste generators, and potential feedstock competitors. Scenarios for different combinations of collection area, landfill status, and ranking were designed, and the total electrical output of a hypothetical AD CHP infrastructure was estimated for each. Additionally, sensitivity analyses were run on two variables of a financial model of a basic facility, and the profitability of statewide infrastructure was estimated.

It was determined that electrical output exceeds 375 GWh/year under all but the most restrictive geospatial scenarios. Also, at an operating profit margin (OPM) of 25%, facility tipping fees are lower than the $30/ton target. Alternatively, host community fees can be increased to achieve the same OPM. A hypothetical statewide infrastructure is profitable except under the same restrictive scenarios identified in the geospatial analysis. The results suggest that the geospatial factors examined will not prohibit the attainment of renewable energy goals in most circumstances, and that AD CHP can be competitive with other organics processors while remaining highly profitable.