The world’s biggest cities are sometimes described as having an “urban metabolism,” akin to living entities that consume energy, food, water, and other raw materials and expel waste. Via a well-planned web of municipal infrastructure, a streamlined urban digestive system enables economic advancement, growth in development, and population expansion by improving public health and the surrounding urban environment.
But even efficient digestive systems have their limits. Over the last several hundred years, one of the defining measures of how far a city has advanced has been its ability to distance its inhabitants from trash, excrement, and emissions. With more than half of the world’s population living in cities today, and megacities – defined by the UN as metropolitan areas with populations exceeding 10 million – on the rise, this out-of-sight, out-of-mind “Waste 1.0” paradigm is facing significant limits. As urban entities gorge themselves on resources, the sheer volume of trash, limited geographies, and sustainability efforts are causing the urban digestive system to back up.
For cities faced with this predicament, treating waste as a strategic resource, a strategy I call Waste 2.0, is quickly becoming an enabler of urban growth. Last year 3.7 billion urban dwellers produced an estimated 2 billion tons of municipal solid waste (MSW) and 375 billion gallons of wastewater, both lucrative potential sources of energy-rich biomass. When this unprocessed waste is shipped to far away landfills in developed economies or dumped in open pits throughout much of the developing world, the energy potential contained in waste is vastly underutilized.
MSW, a primary urban biomass resource, satisfies one of the key requirements for bioenergy deployment: aggregation of biomass in sufficient quantities to allow for projects to be deployed at scale. Accordingly, a slew of companies are advancing projects that convert waste to useable energy in the form of power, heat, and fuels for onsite consumption. At Heathrow, in the United Kingdom, for example, Solena Group is partnering with British Airways to convert trash generated by London’s residents into biojet for use in commercial flights. Plasco Energy Group is also targeting MSW, but aims to produce electricity for onsite generation. Fleets of buses throughout Sweden, meanwhile, run on renewable natural gas produced in anaerobic digesters processing organic waste.
For projects targeting MSW, however, securing a consistent steam of garbage is only half the battle. In some cases, MSW must be separated from inorganic components in order for conversion to be viable. Although waste can be source-separated at the point of conversion, this can add significant cost. Accordingly, Waste 2.0 is also about crowdsourcing separation of waste components at the upstream source in order to decrease the cost of technology deployment. From dedicated waste bins for separate streams (e.g. recycling, compost, landfill) to pneumatic waste collection systems, Waste 2.0 is as much a cultural challenge and a behavioral shift as it is a technological chore.
The European Union has shown that viable Waste 2.0 projects will require a combination of political will fueled by a strong waste management policy framework, economic will fueled by high electricity or fuel prices, and grassroots will fueled by streamlined waste collection infrastructure to facilitate technology deployment around waste.
The last leg of the stool, requiring a cultural shift from the Waste 1.0 paradigm, is perhaps the greatest challenge to increased waste utilization in urban centers. In regions like Asia Pacific, for example, where opportunities to capitalize on waste streams show the greatest opportunity, the ability of local governments to win over their public by branding or selling the idea of utilizing MSW will have a significant impact on the rate of technology deployment. In order for urban dwellers to get a little closer to their trash, Waste 2.0 will require herculean efforts to educate the public, but will maximize sustainable growth throughout fast-growing advanced and developing cities.