Jeremiah Rifkin's book "The Hydrogen Economy" does not give what its title promises.
Most of the book is devoted to historical, political, social considerations, most of which I find well written and even convincing, but which have nothing to do with hydrogen.
However, to me as an engineer, his recourse to thermodynamics to explain the fall of past civilizations appears ludicrous and unnecessary - there is no need to appeal to thermodynamics to make us understand that our world will collapse if it will run short of reasonably cheap energy.
Whether the production of liquid fuels and natural gas will peak within the time frames advocated by Rifkin, or at some other time, there is no doubt in my mind that it will peak, and that well before that time the world must start to convert to renewable energies (assuming that energy from nuclear fusion is still far away from being harnessed).
However Rifkin sees everything easy and cheap. In his chapter on Reglobalization from the Bottom up he advocates the installation of fuel cells in every household or neighbourhood or community, but he seems to forget that "upstream" of each fuel cell there must be a power generator (wind turbine or photo-voltaic cell), electrolytic cells to produce hydrogen and a hydrogen storage facility. Scale economies will certainly reduce the cost of these commodities, but in my mind it is difficult to think that with their combined cost, and the energy losses that will be incurred at each step (electricity to hydrogen gas, hydrogen gas to stored hydrogen, hydrogen to electricity) electricity generation will be cheaper than present day cost from fuel or gas fired power plants.
Also the numbers are staggering. Rifkin writes "Providing these 100 million (per year) new users with an average per capita consumption of electricity equivalent to what US consumers enjoyed in 195 would require the creation of 10 million megawatts of new electricity capacity globally by 2005". Should this capacity have to be provided entirely by renewable sources, as a rough order of magnitude this would require the installation of either:
- From 300 to 500 million 300 KW capacity wind turbines, or
- from 1 to 1.5 million square kilometres of photovoltaic cells
All the above seems to me quite sobering. Particularly the shift to renewable energy sources does not give many hopes to be a way "to lift billions of people out of poverty". Therefore I cannot be as optimistic as Rifkin does - however I share with him the conviction that the shift to these sources is inevitable, and that the world must brace itself to meet the challenges and sacrifices that it will entail. The sooner, the better.