I would love to have a superconducting energy storage device, where I could store up all the excess summer solar power (60ºN, 20h/day) to feed to the heat pump

I would love to have a superconducting energy storage device, where I could store up all the excess summer solar power (60ºN, 20h/day) to feed to the heat pump the rest of the year. But I'd bury it, to contain the damage in case it breaks down. Would it need a Faraday cage too ? So many questions.