Waste-to-Energy: An Opportunity to Increase Renewable Energy Share and Reduce Ecological Footprint in Small Island Developing States (SIDS)

Herlander Mata-Lima,Deborah Cristina Nardi,Deborah Wollmann Silva,Fernando Morgado-Dias,Samanta Andrize Klering,Thays Car Feliciano De Oliveira

doi:10.3390/en14227586

Abstract

Small Island Developing States (SIDSs) are faced with challenges such as reducing the share of fossil energy and waste landfilling. This work summarizes the main aspects of 53 SIDSs that constrain economic development, energy sources, and waste management strategies. An integrative bibliographical review is conducted to synthesize the state-of-the-art of waste-to-energy (WtE) strategies and compare the technologies in light of their suitability to SIDS. The findings show that considering the large amount of waste produced annually, WtE technologies are of the utmost importance to reduce ecological footprints (EFs) and greenhouse gas (GHG) emissions, and to increase the share of renewable energy with the installation of incineration plants with energy recovery to replace fossil fuel power plants. Although WtE is recommended for all SIDSs, the Atlantic, Indian Ocean, Mediterranean, and South China Sea (AIMS) countries exhibit higher population density (1509 inhab/km2) and a high share of fossil fuel in their electricity mix, so that there is greater urgency to replace landfilling practices with WtE. The estimation of potential power generation capacity (MWh) from annual municipal solid waste (MSW) in each SIDS as well as the reduced land area required demonstrate the feasibility of WtE technologies. Only 3% of the landfill area is necessary for buildings and landscaping associated with a WtE plant able to treat 1 million tons of MSW, considering a 30 year lifespan. Furthermore, incineration with energy recovery benefits from high penetration worldwide and affordable cost among thermochemical processes.

Highlights

The economy nowadays—commonly named the carbon economy due to over dependence on non-renewable energy sources [4]—has been running with more than 56% of world population concentrated in urban area as a consequence of demophoric growth [5,6]; this share has an average of 58.4% in Small Island Development States (SIDSs [7]) and can reach 100% in some of them (e.g., Anguilla, Cayman Islands, Nauru, Guadeloupe, and Singapore) [8]
Preference should be given to energy recovery at the expense of landfilling because organic matter (OM) should be subjected to biological processes, and combustible waste—with non-biodegradable matter and low moisture content—can go through thermal processing
As economic growth is energy intensive, it is of utmost importance to highlight that the transition to renewable energy systems is among the main SIDS challenges to reduce the dependence on fossil energy and the vulnerability to oil price shock, and to support sustainable livelihoods

Summary

Introduction

Primary energy consumption and demophoric growth (population + industrial growth with massive urbanization) are among major contributors to greenhouse gas (GHG) emissions [1] and deterioration of ecosystem services [2]. The current pattern of development exerts negative impacts on the rate of energy consumption (causing depletion of the ozone layer because of the excessive use of fossil fuel); waste production (e.g., increase in MSW is related to higher standards of living, and rise in population); and subsequent air, soil, and water pollution [2,9]

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