 Denis Du <unk> , editor of Energy Priorities magazine , commented on the realistic and comprehensive coverage of the book . However , he suggests that The Clean Tech Revolution is not an explanation of the technologies and how they work , nor is it an analysis of energy or environmental policy . Policy is complicated and the authors avoid discussing it in detail . Little discussion ties the various clean technologies together and a " single @-@ minded American focus " dominates . There is very little on the influence of mass transit and urban planning in Europe and other progressive regions . The chapter on water focuses on filtration , which is already an area of considerable opportunity , affecting even " green " industries , such as <unk> manufacturing . 
