> In the long run I hope to see high capacity transcontinental HVDC lines linking continents so we can buy solar power from the other side of the Earth when it's night where we are, and sell our surplus when the sun is shining -- no batteries needed. That's hard and expensive.

There are a bunch of projects in this space. I love going down this rabbit hole.

The EU supergrid is already being built out, and doesn't require linking far flung continents since it links Norwegian hydro and North Sea wind power, among other sources. A mix of geographically distributed hydro, wind, solar, batteries and perhaps geothermal will negate the need for relying on solar + HVDC stretched around the globe along with the geopolitical risks.

Some examples from past HN comments:

https://news.ycombinator.com/item?id=30935073

https://news.ycombinator.com/item?id=29230939

Morocco-UK solar/wind/battery project:

https://www.youtube.com/watch?v=iJunxkln578

Germany is aiming to get 100% of it's electricity from green sources by 2035, so expect a lot more projects in this space in future:

https://news.ycombinator.com/item?id=30500650