Why not just store that solar energy as electricity, and use the electricity to power heat pumps when needed?
What they describe is basically few twisted pipes and a tank.
I'd feel way more enthusiastic about the whole idea if it didn't involve large quantities of highly caustic 30%-50% NaOH solution.
Everyone always forgets about the part where you're cooling down the outside...
We abide by the rules of thermodynamics here boy.
You could have just googled it. The heat is moved around, it's not created. You can move energy, can't you?
Though the practically can be examined to determine how efficient an energy storage process can be versus no storage.