Just need some system to construct solid fuel blocks with that excess energy. Could bypass the panels and create wood, but maybe there are other better strategies. Maybe some places can fit a hydrogen storage cavern in their backyard.

> solid fuel blocks with that excess energy.

The best solid fuel you can dig out of the earth has a "plug efficiency" of few percents.

It took evolution billions of years to get to capture carbon this efficiently.

Now, think of how feasible it is to contend with nature when it comes to thermodynamic processes.

You produce Hydrogen or Methane during summer and feed fuel cells or combined cycle gas plants during winter. It's not terribly hard, it's just a bit expensive right now. Most countries already have infrastructure to store large amounts of natural gas, which can be reused for this.

If you have a grid, it's not an issue to rely on powerplants for that.

Your biggest consumption/production variance is within 24 hours.

This is why I made a graph: https://flatline.org.uk/daystats.html (click top graph for intraday detail). It's both, really, but then I am fairly far north. There's a three month period of daily production being <20% of summer peak.

Uh, you must be living quite far up north! There are people living there, wow! (Snobbery of a man who used to live in tropics.) Just joking.

Though, 26 vs 0.15 kwh variance is still nothing in comparison to the worst daily production on record, and nil you get at night.

Well, can only say that there is nothing even imaginable on the horizon to being practical for seasonal scale energy storage. Even for a small country as UK, you will need a small ocean to store enough energy for one season worth of consumption.

Depends how close to the poles you get.

How about vanadium redox batteries?