Solar is the way to go if you have a good position on a roof available.

I'd prefer to save my roof area for solar PV panels. These usually have a much better return on investment than solar thermal hot water, particularly in cooler climates where solar thermal hot water requires a lot of boosting in winter, with either gas or electricity. Solar thermal may overheat in summer (wasting that additional heat), while not producing enough heat in winter. Solar PV can be used to heat domestic hot water, & power any other electric needs in the house. If there is still surplus electricity, this will be exported to the grid & earn you a little extra cash.

My ideal set up would be a large solar PV system (5-6kW) on the roof, with some sort of electric hot water tank system. Either a standard electric element tank, or a much more efficient (4 to 5 times) but more costly heat pump. If going the heat pump route, do your research. There's some very good brands, but also some duds.

Hi there dd our experience with solar in the past has been solar panels and separate solar hot water. the only way a 5-6kw is any good to you is to have a battery pack to store the energy that you wouldn't normally use as you gets peanuts for the excess, not what it was,

We have 2 x 1.5kw, a large house with swimming pool with two hot water services, we have left over energy from these that goes back to the grid for peanuts. You are only able to use your solar power from somewhere between 0800 and 1700 each day outside of that when most people are home you are switched back to buying power. The new now affordable battery packs with solar panels is the way to go at the moment. cheers

All comes down to how much you want to spend.

All good to go the options as many others have suggested but this while being overwhelmingly a great sustainable option the costs are significant! Unaffordable for many when all they just want is cheap hot water.

Gas Instantaneous is still a very cost effective option, easy to install, cheap to run ( at this stage anyway) but locate it as close as possible the preferred hot water tap.

Heat Pump HWS are again very efficient but currently are still rather expensive. My electrician friend swears by his Heat Pump...

The old school electric HWS is slowly being phased (no pun intended) out as they use a lot of electricity, etc. but many owners will just replace the old one with a new one. Sometimes its the cheapest option although not as sustainable nor as cheap to run.

Your budget is the key (to everything) and is just as important as anything else. Get the best that you can afford thats within your budget!

forgot to mention that buying the 2 x 1.5kw solar was heaps cheaper than a 1 x 3kw, we have a couple of clever guys that live in our street, one a plumber and the other a refridgeration guy, they did the research and found the company that we all purchased from. The plumber installed both the solar hot water and the 2 x 1.5kw.

Our solar installed $3000, still not cheap but has saved us a lot of money, we now need to be able to afford the newer cheaper battery packs cheers

What's your climate and do you have good solar orientation? I see a few people are suggesting heat pumps. I don't know if the technology has improved but when we were researching a few years ago we were told they are not as good for our very cold winters.

From what we have been told it doesn't matter if the weather is cold as long as there's some clear skies the solar will work, don't know about heat pumps and the water they waste. When we were looking into solar most were charging $8-10 thousand dollars for 3kw. In most cases these older systems can still use the new batteries.