Comment by RGamma
3 hours ago
Renewable electricity in Germany is already at over 50% per year and climbing steadily, but heating, mobility, land/resource/artificial fertilizer use, pollution and circular economy are still lagging (esp. accounting for the fact we're externalizing some of those by cross-border trade).
I guess we're trying much harder than most, but it's expensive, as you said, and politicians have become very careful to push things further. That said, I do think it's totally feasible in theory, it's just there's a lot of powerful bad actors out there throwing wrenches in the works.
The challenge is with the remainder, which is actually a much bigger problem.
Thermal heating for example, even using heat pumps, will require more than 5x the existing electrical grids peak energy capacity - just on its own. I’ve done the math several times, it’s staggering.
And it will do it during typically minimal insolation times.
Germany has made good progress, don’t get me wrong, but it highlights just how hard of a problem this really is.
W.r.t. heating did you also consider the effects of increasing local production as well as transferability and variability of load (e.g. requiring larger heat pumps and other "steuerbare Verbrauchseinrichtungen" to be "adjustable", which Germany does)
It’s a straightforward thermodynamic equation - x fuel burnt (and useful heat from that) vs maximum theoretical efficiency for heat pumps for equivalent heat.
The reality is likely worse for a number of reasons, but even if way better it doesn’t get around that you’d need many multiples of the entire electrical grids peak capacity to come close. And that is assuming there is zero other load on the grid, which isn’t going to happen.
If everyone completely redid all their structures and all their use of heating, and installed all the best heat pumps, AND doubled grid capacity, maaaaybe. But we’re talking massive amounts of Capital. Capital that used to be cheap, but isn’t anymore.
Far more Capital than likely has been spent so far on renewables too, but it’s hard to calculate it because of the sheer distortion that it would cause trying to do something of this scale.
It might be legitimately cheaper to buy Northern Africa and move all Germans there instead (in new construction). That seems pretty unlikely for sócio-political reasons though.