Hydro can also provide base-load. Especially when used as storage for overproducing intermittent renewables.
It is still highly location specific though.
Might there be value in efficient energy transport using high voltage DC? There is probably a lot less fluctuation in power supply and usage if you sum up over larger areas (especially east-west, as you average out time-of-day effects)
Everything else apart from solar is generating AC. You'd need expensive converters and more expensive switching equipment with arc supression in order to transport DC. HVDC is mainly used for underwater cables because it's more efficient to transport DC than AC by cable. We'd probably benefit by interconnecting these cables coming from offshore wind farms and imports with parallel land based HVDC infrastucture.
I was thinking of cables like NorNed for moving surplusses around. Especially if such a cable runs east-west and can ease some of the temporal effects due to both people's living pattern, and solar intensity.
Yes, that's what Renewable electricity superhighways in the Wikipedia link basically refers to. But it's a bit ahead of its time and there are still challenges to overcome and more renewable capacity to be built in order for HVDC ground based networks to be viable economically. I’ m sure we'll see it being built in the next 20 or 30 years.
It is still highly location specific though.
Might there be value in efficient energy transport using high voltage DC? There is probably a lot less fluctuation in power supply and usage if you sum up over larger areas (especially east-west, as you average out time-of-day effects)