A bit of an offtopic: lucky (unlucky) to live in a country where winter means temperature around 0 (down to -5/-8 C) I simply put a 210L rainwater collector on my balcony. Best thing ever to be able to take an ice dip from comfort of my home - with an airbike for warm-ups, and a warm shower. I'm not a giant, so 210L is enough to duck and get covered to level of my shoulders. Below €20 and zero effect on electricity bill :)