The main point is that once we generate a significant proportion okf electricity from renewable sources there will be times when a surplus of energy is being generated, and apart from the pumped storage reservoir at Dinorwic, we have no way of storing it. If we could convert that surplus energy into liquid fuel (using carbon dioxide which is in, or would otherwise go into, the atmosphere), we could also begin to decarbonise transport emissions. The attraction of this approach is that the methanol produced can be added to petrol and burned in existing engines without modification (as in Indy car racing or as we used to do during the second world war). The alternatives - charging up electric cars, or using hydrogen - require enormous infrastructure investments, which this doesn't. It does, however, need time and money to develop into a scaled up and commercially viable process.