100% Renewable supply? Comments on the reply by Jacobson and Delucchi to the critique by Trainer

I recently criticised the claim by Jacobson and Delucchi that renewable energy sources could meet world energy demand. Jacobson and Delucchi replied defending their position. This is a response to the main points made in that reply. The main issues are to do with intermittency of renewable energy sources and the implications for redundant plant and storage, vehicle to grid systems as a storage solution, the embodied energy costs of renewable energy, and overall system capital costs. It is argued that Jacobson and Delucchi do not provide satisfactory analyses of these issues and that they do not show that energy supply can be 100% renewable. This discussion is intended to clarify some of the core issues in the debate about the limits of renewable energy.