An article entitled "Garbage In, Megawatts Out" recently appeared in MIT 
Technology Review at the web site: 
www.technologyreview.com/Energy/21029/. This article gives a glowing 
picture of plasma arc gasification of waste while ignoring the downside. 
I have posted the comments below to the TR website and sent them to an 
Ottawa newspaper, etc.
Dwight Adams,
Emeritus professor of physics

The article entitled “Garbage In, Megawatts Out” appeared on July 02 in 
the MIT /Technology Review/ reporting that the city of Ottawa, Ontario 
had approved a gasification facility that would use 400 metric tons/day 
(equal to 880 US tons) to produce 21 megawatts of electricity. Before 
this is hailed as a breakthrough for turning waste into energy, it 
deserves further scrutiny. It must be compared with recycling on the 
basis of the energy produced, effects on the environment, and the economy.

    * Energy—Using the energy content of the waste consumed, the
      efficiency of the Ottawa facility can be calculated to be below
      20%. For each ton of material used for fuel, another ton must be
      produced from virgin materials to replace it. The US EPA has
      supplied data on the energy required to produce a ton of each
      constituent of municipal solid waste from both virgin and recycled
      materials. The energy saved by recycling is three to five times
      that produced using waste as a fuel. Recycling the materials
      instead of using them as fuels saves more than the “megawatts out”
      even if the thermodynamic limit for energy efficiency could be
      achieved.

    * Environment—Producing new products from virgin raw material
      requires processes such as mining, use of fossil petroleum for
      plastics and fuel, and cutting or growing trees, all of which are
      detrimental to the environment, and are not sustainable. Recycling
      paper and plastics would mean that fewer trees would be cut from
      Canada’s boreal forest and less of Alberta destroyed in extracting
      petroleum from oil sands.

    * Economy—The EPA-data indicates that recycling the 400 MT/d would
      provide 1500 jobs with better pay than the average of all jobs,
      and add $25 million (US) to Ottawa’s economy. Recycled materials
      are essential to industry. Without recycled paper and cardboard,
      e.g., newspapers could not be printed nor products shipped in
      cardboard boxes.

Ottawa’s low recycling rate, especially the 17% for commercial waste 
that constitutes 70% of the waste, provides the opportunity to recycle 
much more of its waste, saving energy and the environment, while 
stimulating the economy. Ottawa should follow the lead of San Francisco, 
Guelph, Edmonton, or Vancouver with a zero-waste goal.