Off the grid shower ideas

Hi, I'm moving off the grid where I'm using 1kw solar panels for electricity and the access to water is done from a water well using a pump. I can't seem to find a simple solution to have hot water during the cold season( 3 months winter mostly). For March-November i'm pretty sure I can use solar panels for hot water but when it comes to winter until this point in 2016 our complicated minds only created complicated solutions. How can this be done in a simple manner? Like having tank for let's say 30L inside the bathroom with some kind of a method that can easily heat the water. All this boilers and complicated methods really mess with my head, why we can't we just invent simple methods for a simple way of living, press a button get some hot water, no systems that require maintenance, etc. Any idea is welcome. Thanks . Adrian