In Finland in summer you can have around 20 hours of sunlight per day, so there's a lot of energy free for the taking. But could this tech work affordably at the level of individual properties (homes, apartment blocks) ? Could it be scaled down ? And well, if you can have a heat battery then why not a cold battery too ? Winter cold spells in southern Finland can hang at around -20C (subzero F), so you could store tha…
Once I asked the cold-battery question as well and I got a very smart answer: there is no "colder", there is just less warmer.