Problems mostly solvable isn’t the same as entirely solvable, G. The ones that aren’t floor the whole enterprise; exactly as Gail Tverberg analyses, with the debacle of the German test case: They haven’t solved the cripplingly-expensive issue of having to run constantly-idling coal/gas/oil-fired back-up generator sets: essential to handle the intermittency/storage problem. That intractable puzzle has brought their solar-Germany hopes to an impasse.
Here’s a useful analysis by Gail, that lays out the basic problem (all emblematically encapsulated in the central issue of EROEI: energy returned on energy invested):
Tim Morgan’s ‘Surplus Energy Economics’ website is worth some study too (intro. essay linked below). Both he and Gail see solar, wind, and even adding in available hydro, never offering more than about a quarter of current energy demand, even in best case reckonings.
My intuition - because essentially we’re dealing with an imponderable rational calculation here - is that ‘renewables’ will never amount to more than a boutique energy source, for as long as we’re still trying to run the present simply non-sustainable energy splurge. Not for much longer, it’s now becoming clear; blame that - air-headedly - on Putin, if it tickles your prejudices; it’s not his fault, of course; it’s The Limits, making themselves unignorably known.
And that’s to leave out the further crucial discussion that none of the ‘renewables’ are actually renewable, since none of them can be constructed, run, maintained and replaced periodically without constant energy subsidies from fossil-hydrocarbons. Try going into the woods with axe, saw and knife, and building a solar panel there, with only human muscle power, using only the materials you can find there. Doable for a Cretan windmill, or for a water-wheel, but not for a solar panel; some (earlier) technologies are bootstrappable from the ground up, as we did in previous centuries; present day ones, not so much. (And even with the hand-crafted devices, there’s still the question of where are you going to find - or make by hand, in the woods - the generators for them to drive…?)
We really need to get off this empty fashion fad around ‘renewable’ wind and solar techietechie, as Jim Kunstler is realising sardonically. Wind/solar are not going to ‘save’ us - except in their real, ancient, function which have been working faultlessly for millennia, and which I described at the start of this thread as using sun energy to drive both the yearly manufacture of a great global weight of biomass, through photosynthesis; and, of course, the delivery of rain and snowmelt to all the landward places which rely on them.
Control of the rain is beyond us, of course, despite all our ‘weather management’ fantasies;* and the best way to assist with the biomass creation is through permaculture. That’s what we’re going to have to rely on, once we’ve got over our startrekkytechietechie myth-fantasies:
*The only weather steering - I won’t call it management - that I know to be workable, and that only very occasionally, is in conjuring up winds and thunder-storm downpours, which is sometimes done by gifted shamans. Not a technology to run a modern hitech industrial society on, I wouldn’t imagine…