So this is just an idea for people who are looking at reducing your geyser's power usage.

 

My geyser was replaced by insurance and they refused to place it inside the house again (flat roof), and so it was installed on top. Now I haven't seen geysers specifically for outside use, and so the first thing I did was to put a geyser blanket on. Well that lasted about 2 months (The blanket was not made for "outside use", and crumbled). I did however install a geyserwise timer, and set it to only run between 04:00 - 07:00, and 16:00 - 19:00 daily. (geyser set to 55 degrees)

 

As winter dragged on, I monitored the temperature and noticed that overnight, just prior to the element kicking in, the temperature would be at 23 - 25 degrees. This meant a delta of 30 - 32 Degrees.

As builders / leroy merlin did not have an "external" blanket, I decided to DIY something myself. I bought some aerolite (the thickest one I could get), and bought a strip of the galvanized sheet from the pet store (They use is for bird cages).

I have noticed that my geyser is now running between 35 - 37 degrees prior to "switch on", which to me is MUCH better (delta now 18 - 20 degrees). I still have to see how much it saves though.

 

I like this set up. My geyser is also on the roof and the blanket was also destroyed in no time. Was planning to built a timber housing structure like a small wendy then wrap the geyser in Aerolite as you did.  I think timber is less conductive to cold and should work better. But I like how yours fit snug and looks neat 👌🏽 

Update, covered my geyser. Box is big but everything is inside