How rapidly can we transition to 100% renewable electricity? Vaclav Smil, an expert on historical energy transitions, argues in his book that the process of restructuring the modern high-energy industrial and post-industrial civilization on the basis of non-fossil, that is, overwhelmingly renewable, energy flows will be much more challenging than was replacing wood by coal and then coal by hydrocarbons. Smil seems to be under the incorrect impression that we must focus on changing the fossil fuel primary energy inputs – coal, oil and gas – to renewable energy, presumably because the traditional energy flow diagram (see figure) starts with primary energy on the left, then flows through transformation processes (e.g. combustion in a power station) in the middle of the diagram – to provide on the right-hand-side, after substantial energy losses, the end-use energy and hence the energy services we demand: a warm home in winter, hot showers and cold beer. However, if we start by considering what energy services we really need, we can integrate energy efficiency and conservation with renewable electricity, thus reducing the demand for end-use energy, which will be used mostly as electricity. Then, when we reduce electricity use by a certain amount, we substitute for approximately three times that amount of energy in primary fossil fuels used for electricity generation. This is because of the low efficiency of conversion of fossil fuels into electricity, as illustrated. A strategy that moves from right to left is much easier than the opposite. Because Smil’s assumptions are questionable to say the least, his argument that the transition to renewable electricity will take longer than historical energy transitions, is poorly based. On the other hand, the facts that wind turbines, solar PV, CST, batteries and energy efficiency technologies can be mass produced rapidly and are less expensive per unit of electricity generated or saved than new fossil fueled and nuclear power stations, gives confidence that a rapid transition is technically and economically possible.
Energy Post 29th June 2018 read more »