This story illustrates both the upsides and limitations of trash-to-energy programs.
On the positive side: many sources will pay you to take their trash from them. There's nothing like free energy.
On the negative side:
- Sweden's exhaustion of its own sources of trash show that the concept is inherently limited, even in an abundant consumption economy. That is, one which is producing ample waste streams. As the article notes: "the fastidious population of Northern Europe produces only about 150 million tons of waste a year, he said, far too little to supply incinerating plants that can handle more than 700 million tons." That's a kind way of saying that Sweden's overbuilt its trash-to-electric capacity by 467%.
- Some trash is more equal than others. Countries such as Switzerland and Germany which offer highly segregated waste streams find themselves with many takers. Italy, who is stereotypically ... less organized, not so much. Again, noted in the article.
- There are issues with contaminants, which require monitoring of the input waste stream, the combustion process, and emissions controls.
- Ultimately there's the question of how much trash will exist in a world with a leaner energy profile. In which case it's likely we'll find that there's a very high excess of trash-to-energy infrastructure, though much of it might be applied to other feedstocks, including biomass. Though this also has its limits:
http://globalecology.stanford.edu/DGE/Dukes/Dukes_ClimChange...
Putting this in an American context (likely familiar to most readers):
Americans produce 230 million tons of waste stream, about 4.3 - 4.6 pounds per person per day.
http://www.learner.org/interactives/garbage/solidwaste.html
http://www.epa.gov/osw/basic-solid.htm
In a best-case scenario, this would be pure biomass. I'll assume the same energy potential as carbohydrate (oil-based products will have roughly double this, glass, metal, and inorganic solids less), at 4 calories/gram, or roughly 971 GWh of electrical energy. That's an appreciable amount of energy, but given that annual electrical production is 4.1 tera watt-hours, my hypothetical puts waste-stream energy production at less than 1/4 of electrical energy usage, or roughly 6% of total energy usage. And that's before considering the energy requirements of collecting and processing the wastestream itself, or the effects on waste production in a reduced-energy environment.