In response to Jack Ponton (Letters, 12 March) I would suggest that we should not lay too much emphasis on the individual costs of essential components of a necessarily composite energy supply. We do not, and probably never can, have sufficient fast response hydro to buffer a major erratic constituent so, no matter how many wind turbines we have, an all-renewables on- demand electricity supply is sheer fantasy.
We also need our own gas (get fracking!) and to continue to be part of the national grid system (and beyond?) with its eclectic mix. My view is that if we really want to be good earthlings then, like the Swedes, we should go for a substantial nuclear base-load component.
(Dr) A McCormick