The solutions to this problem all involve adding substantial energy storage and additional long distance transmission and distribution along with grid demand response changes. The combined cost of this additional (yet to be developed) infrastructure far exceeds the cost of the wind and solar generation which is already very high.
This paper from Mark Jacobson et al. is a very comprehensive and imaginative analysis that shows how it might be done by 2050 within known technological constraints. It draws on deploying a wide range of new technologies and avoids reliance on battery storage. Instead it relies on energy users storing heat and cold and the generation of hydrogen from electrolysis for transportation fuel. It makes extensive use of technologies that have proven difficult and expensive, like Concentrated Solar Power with thermal storage and offshore wind power. Given the long periods that wind and solar can disappear the paper does not make it clear how this is covered. Also the geographic constraints of the UK or northern europe covered by David MacKays book are not addressed.
A central problem with academic solutions is they rely on government support to prop up the costs and mandate behavior. This can work up to a point as current wind, solar and nuclear can testify. On the other hand, history can also testify to the fickle nature of government support for energy. Its hard to imagine stable government support out to 2050.
This StratoSolar analysis of a 2050 energy scenario addresses the same problem. The StratoSolar solution has the benefit of not needing any changes to the grid or energy consumers. StratoSolar power
plants include gravity energy storage and provide a drop in replacement for dispatchable electricity. The only decision is where to put them. They can be deployed to provide new capacity in the developing world or replace fossil fuel capacity in the developed world. Because they provide low cost electricity they don’t need government subsidy or mandates, just regulatory permission to exist. As StratoSolar electricity continues to fall in price, end users will adapt to consume it over other sources. Natural market forces will drive the adoption of the scenario. This has great advantages as it works worldwide without global political agreement.
By Edmund Kelly