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.