One day I may be forced kicking and struggling to replace my small coal fired hot water heater (costs a $1 week for all the hot water I want) and go 'GREEN'. Wott a Sick Joke !!!)
Being located around the 900 metre (3000 foot) mark on the Central Tablelands with no near access to Natural Gas means either LPG (Instantanious), Solar panels or Heat Pumps.
Mains electricity useage costs are now passing the realms of fantasy.
Solar Panels have never been favoured here because of severe frosts and heavy cloud cover, LPG has to be delivered so Heat Pump types may be an option.
During the winter very cold 'Southerlies' straight from Antartica via Kosiosco continuing to roll up the western side of the Divide passing over here.
We dont need to hear that snow has fallen on the Southern Alps as the temperature drops accordingly.
Like everywhere winter's vary but using the 'Worse Case Scenario' situation, in my over 50 years in the area, during one cold snap Frost began forming as soon as the Sun set and within 2 hours car windscreens had to be scrapped clean.
by 10pm Cars had over 4mm (1\4 inch)of 'HoreFrost', little vertical icicles covering the body work.
You could see the ice crystals dancing in the lights.
During that snap of several days , the days were windless crystal clear hitting maybe 8 to 10 C briefly before sliding back to bottom out after midnight to around Minus 10 C and holding steady there untill after daylight when as defrosting occurred, pipes happily burst keeping the Plumbing fraternity in work for over a week.
Wind Chill is another factor that occurs here but you seldom see it used in determining suitability for installations.
The Northern Hemisphere has weather we only read about but it doesnt seem as though any of that knowledge is applied here.
While I will be sorry to see the little donkey go, it would be nice after some 30 years to have hot water available without having to light the boiler.

As we have seen with the recent Roof Installation fiasco, there are an appreciable number of shonks out there selling inferior products with equaly poor installation.
The days of using Brand names and displayed Trade Qualifications based on a hard earnt reputation are long gone when choosing products and Installers.
So I am curious as to can these work here and where physically would it need to be located apart from allowing a clear airflow for the pump?
Remebering that my South and West side of any structure are the worst weather sides.
Like the American Indian, up here you try to 'face' the rising Sun for all doors and openings on garages, sheds and Lean To's unless you like 40 knot freezing Sou'Westerlies blowing you all over the place.
Thanks for any and all thoughts.