CHOICE membership

Solar Hot Water

Curious to gauge peoples opinions on solar hot water systems. I live in S/W Gippsland -so who is a highly recommended installer that is prepared to travel { ?] and what brands seem to be the best { ?].ie performance reliability cost installation.
Cheers Martin

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When we lived in Brisbane, we swore by our solar hot water system (SHWS). It was a 315 Aquamax with 2 collector panels (rebadged as Conenergy).

Our how water cost us next to nothing each year (no more than $3-4).

Our system was a lo larger than what we needed on a day to day basis which worked out better for us. It meant that we would have water 2-3 days/3-4 days in winter/summer if there was no sunshine. This meant that we didn’t need to boost very often and why our how water costs were extremely low.

If one has solar PV with a low FIT (that only the energy supplied to the network is reimbursed), then it is worth exploring a timer for your meter board. One can set the time to boost only at times when PV generation is usually at a peak (depending on the orientation the panels) and then it may be possible to reduce SHWS costs even more.

If I were to install a new system in Tassie (where we now live), I would opt for the more expensive stainless steel storage tanks. These have an long life and should over the life of the SHWS result in cheaper overall costs.

Unfortunately can’t help with installers in Victoria, but other may. If you know of anyone who has SHWS in your local area, it may be worth asking who installed it, what make, model and tank capacity was installed and how it has performed. This may give you a better insight to what may be needed to meet your own household demand and also reliable local installers.

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There are a number of topics where information can be found on Solar Hot water systems. I suggest that doing a search on solar hot water might pay dividends for you. Sadly it is hard to bring them altogether for you but as a start:

Some of the links may be more relevant than others but I hope they help.

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We’re in Ashwood in inner South-Eastern Melbourne. We bought a Thermann evacuated tube solar water system about 4 years ago and couldn’t be happier. Michael Lomas, a plumber who lives to the west of Melbourne, installed it for us.

It was about $6000, but (bearing in mind we have 3 teenagers) on top of the ‘service to property’ charge, we don’t pay more than about $5/month in gas.

Best of all, if you turn off the gas booster, for most of spring / summer / autumn, you can survive with just the pre-heated water from the system.

A very very astute purchase.

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Hi! which is the best solar hot water system for cool climates.

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Welcome to the Community @Snowey,

Choice has published some general information and solar HWS has been discussed a bit, so I merged your query.

and a focused one on solar HWS

The context of a ‘cool climate’ could be different from a sunny or cloudy one, ie at altitude it could be cool yet very sunny and amenable to solar HW production. In contrast Melbourne vicinity is a cool climate with lots of ‘cool’ cloud formations on most days, making solar anything a different proposition - noting we have lots of PV and solar HWS systems in the region. But that was not your explicit query.

We have a few members with relevant experience and knowledge, but could you be more specific with the location of interest?

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Thanks PhilT for the information.
We live in North Central Victoria about 500 metre above sea level. Get lots of -1 nights causing issues with solar hot water. Need advice on how to get a more efficient model.
Kind regards

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I can’t compare all systems but I hope I can give some help.

The standard approach is to have the tank on the roof on top of the panels so that the hot water circulates by convection. When you turn on the hot tap the cold water goes in the bottom the hot comes out the top and the system keeps going. If things overheat a pressure valve releases on the roof and the water released goes down the gutter. There is an electric heating element so you can have hot water after several days of cloudy/cold weather. This is fairly simple with few moving parts. However everything is on the roof including a heavy tank.

The high tech approach is to put the tank on the ground and the panels on the roof. Since the tank is lower than the panels you need a pump to circulate the water as convection won’t work. This needs control circuits and electricity. Not so simple and more parts and equipment. If the power is off you can’t circulate water.

Neither system is cheap and you might want to consider if in the long run having solar PV power and heating water with a heat pump is going to be better. One advantage of such a system is you can control when water is heated and thus increase your use of your own power. It is much more efficient to use your own power when it is generated than sell it cheaply to the network and buy it back expensively when you need it. No doubt the energy capture of solar HW and solar PV per square metre of panels are different but I don’t have the figures. There are many variables to consider in this choice including the capital cost of all the gear required, performance and maintenance.

Solar hot water needs heat, mainly in the form of infra-red from the sun. Solar PV needs light but not heat. I haven’t done the sums but different climates may well favour one or the other.

I went with the roof tank and bought a Solarhart. I was happy with the installation and it has performed flawlessly since. My main reason was simplicity and low maintenance and that the company has been in the game for decades whereas the others had not. YMMV.

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Generally evacuated tube systems are better than flat panel systems in higher, colder areas. This PDF document gives an indication in the difference in efficiencies.

However, if you have regular subzero temperatures, the system needs to be designed to cater for potential water freezing in the system…to protect the system from freezing which can cause damage. This website provides some information on different cold weather systems …

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We live in metro Melbourne and have a 30 tube evacuated tube solar hot water system with gas booster. I bought it about 5 years ago and it cost about $6000. We have mum and dad and two teens (one of whom takes very long showers) and it costs us about $1/day for hot water now (service to property charge on top of that of course).

In general, I’m super happy with this purchase.

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