Can anyone please help me sort through the mine field of hot water systems to choose from.
I am pretty sure that whatever we decide on will be more energy efficient than the 125 litre Rheem electric hot water system. I have been quoted on a brand called Conergy - we are wondering if a 300 litre tank is sufficent for 5 people who are not water conscious when it comes to showers

Naughty!
We are looking at costs between $3000 - $3500, so I want to be making the right choice.
We are also in a frost prone area, which can be an issue.
Does the tank have to be on the north facing roof - one company said west is fine because the panels are black they absorb the heat, but I do wonder.
The other company says that there is not really enough room to place the tank above the solar panels that are already there, because it may flatten the ridge cappping. The tank would be placed between the supports which is also not ideal, they suggest the tank on the ground option eg split system. We then have the option to upgrade to a 400 litre tank, but I'm wondering if we really need that as we expect the adult children will want to leave home soon, one has gone, two to go.
What systems do you all have?