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Solar hot water in Canberra?

By butterflygirl - 7 January 2011 32

We are on the market for a new hot water system as our old electric model is cactus.

I’m wondering if anyone has any comments on their experience with solar hot water in Canberra, brands, efficiency, relability?

I am currently comparing Solahart and Edwards. Edwards has a stainless steel tank and seems to have better quality fittings, but the panels are not as efficient as the Solahart ones. I’m concerned that in winter this will mean more days using the booster. Solahart seems to have great efficiency, and gets more RECs than the Edwards, but the tank is steel and hence has to have a sacrificial anode.

Thanks for any info you can give!

What’s Your opinion?

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32 Responses to
Solar hot water in Canberra?
parle 9:30 am 08 Jan 11

@butterfly02: What’s your current quarterly bill for the off peak electric hot water? Solar becomes even better value the more you use it but there is still a break even point, it might be beneficial to work that out to help with your decision on what system you should get.

butterfly02 11:15 pm 07 Jan 11

Thanks for the responses, great details Aidan and Michcon.
Having been around our neighbourhood this evening and taken a poll of those who were home, I can conclude:
Solahart owners have a life and aren’t home on a Friday night.
2/3 Edwards owners hate their system and think it doesn’t work properly.
1 property had the solar panels up just for decoration and didn’t know what brand it was (it had broken several years previously).
Only one place had the evacuated tubes and they weren’t home either. So some more research to do next week into tubes I think.

OpenYourMind 7:03 pm 07 Jan 11

We’ve had an Edwards system for 12mths and it has been great. Still needs a boost on cloudy days, but on the days when it’s just running on solar, it’s a great feeling. From everyone I’ve spoken to, long after you’ve forgotten the cost of solar hot water, it is still delivering.

michcon 5:21 pm 07 Jan 11


In April 2010, after considerable research into Solar Hot Water systems we purchased an AAE 30 Tube Solar-Electric System with a 315L Marine Grade Stainless Steel Tank from Planet Power.

There were lots of options available, but I choose this specific system on the following basis:
1. I understood evacuated tubes to be more efficient in this part of Australia than flat panels.
2. The stainless steel tank was approx $700 more expensive than the equivalent vitreous enamel tank, but the cheaper option required sacrificial anodes be replaced every 5 years. After the cost of a plumbers call out fee, labour, and parts, I expected this to be up to $400 every time, so I’d be out in front before the 10 year mark and I don’t intend on moving before then.
3. My preference was for the tank to remain in the internal cupboard, so gas was not going to be an option.
4. I wanted the larger tank to future proof us for when we have kids.
5. AAE is Australian owned, had a good warranty, and offered the strongest glass on the tubes.

The information I found hardest to obtain was how well do solar systems actually perform in Canberra. Hopefully I can assist here.

With Solar systems you can chose to either leave the booster on all time, and it will kick in when needed to assist the solar in maintaining a constant temperature, or you can take matters into your own hands.

I decided to regulate this manually, by flicking the circuit breaker on when the solar gain wasn’t keeping up with the demand (temperature fell to 45 degrees), or if we had a few cloudy days in a row. Usually in winter, this meant boosting it overnight once, or at very worse, twice a week. This also met a requirement to heat the water to minimum 60 degrees every week to kill of any nasty bugs.

Below is a primitive table demonstrating how effective the system has been in lowering our electricity consumption for Hot Water only. We are in a household with 2 adults, and would host guests for a few nights every month, but my wife really feels the cold and during winter would regularly have two long hot showers per day. Q1 is an estimate because we are only a few days into it, so I have based it on the reduction I experienced during Q4. Note also, our system faces North West, so we lose a small amount of solar gain there.

Period Q1 Q2 Q3 Q4
Pre Solar kWh 605 1002 1110 773
Post Solar kWh 45* 353 456 55
Reduction 93% 65% 59% 93%

Overall Reduction 77%

As for the installation, it was completed within a day, and was top notch, I couldn’t be happier. The plumber (Nick) was a young bloke, did a great job, and I haven’t had a single problem with it. Hope this helps.

aidan 5:13 pm 07 Jan 11

We have a Hills Evacuated Tube system supplied and installed by Enviro Friendly

There have been other threads about this topic. Here is one I found:

I went for evacuated tubes:

– they are more efficient in cold climates like Canberra
– they are frost resistant (the water doesn’t flow into the tubes, but through a manifold at the top)
– they aren’t affected by boiling (there is a small amount of water in the manifold that can boil and be released as steam, but after that no more water is pumped into the manifold, so no constant boiling)
– they are more expensive than flat plate
– they need to be mounted at 45-55degrees from horizontal (if not they overproduce hot water in the summer and under-perform in the winter and late autumn when the sun angle is low)
– get your pipes insulated (lagged) as the tempering valve combined with losses through pipes made for uselessly cold water in our kitchen (unlike others, we decided to temper our kitchen and utility area as solar hot water can get dangerously hot in summer).

Our unit (30 tube, 250L, electric boosted) runs without any boosting from September to May. We have a household of five (3 kids under ten) and do a fair bit of washing. During summer 3 cold/cloudy days in a row will mean we need some boosting. In winter we boost for an hour or two on days when there hasn’t been pretty much constant sunshine from 10-3. We had a separate switch for the electric booster installed inside so it is convenient to turn on when we need it.

Felix 4:25 pm 07 Jan 11

I’ve had a top of the line Edwards for about 8 years. it’s generally good, but does still need some boosting in cloudy weather. I’ve got gas boosting, which is cheaper and environmentally preferable to electric.
I have experienced the boil over effect sepi speaks of on VERY hot summer days, but only a few times each year.
Overall, I think the Edwards is solid and good quality, but I suspect there might be better/newer alternatives available by now. I don’t know all the details, but the evacuated tube systems, like semaj mentions, are meant to be very good – probably worth trying to get some cost/performance comparative data there.

semaj 4:13 pm 07 Jan 11

About 6 weeks ago I put in an Apricus evacuated tube system with electric boost, which I had installed by 6 Star Hot Water and Plumbing.

Couldn’t be happier with the product and the installation. The guys from 6 star where some of the most professional tradies I’ve ever dealt with. They even took every single scrap of rubbish with them when they where done.

Even with all the rainy days we’ve had recently, I’ve only had to use the electric boost once.

Pork Hunt 3:58 pm 07 Jan 11

Bloody Cathodics and their sacrificial anodes…

Grail 3:52 pm 07 Jan 11

My parents live in Tuggeranong, their original Solarhart was replaced after 15 years. In the period since it was originally installed, technology has changed and the newer systems should theoretically be more robust.

Ello Vera 3:21 pm 07 Jan 11

I’d avoid Solahart solely on the basis of their stupid ads. If I see Lisa and her towel one more time I will throw something at the telly. Vacuous, cliche-ridden tosh.

sepi 3:12 pm 07 Jan 11

We have an Edwards, and it does do that thing of overboiling and voiding a tank full of boiling hot water all down the bottom of the verandah. It did this multiple times last summer on really hot days (maybe 4 times).

Other than that, no issues with it.

Deref 3:00 pm 07 Jan 11

Give some thought to a reverse cycle system. We replaced our old off-peak electric unit with a Rheem unit about a year and a half ago and it’s been brilliant, including through winter.

butterfly02 2:40 pm 07 Jan 11

Spectra, it’s my understanding that Rheem actually owns Solahart and Edwards, but yes, Edwards is marketed as the premium brand. A lot of what I have been able to find online refers to people living in areas other than Canberra, not requiring frost-proof systems. The Solahart system has an anti-boil function so that there is not a constant loss of water when the temperature gets up high, but the Edwards does not get hot enough to boil (according to the sales guy who came this morning) as the panels are not as efficient (again accoring to him because they don’t want the system to boil). Hence my concern that in winter I will spend more time boosting the system.
Helen – thanks! Have your parents had to service it often?

Helen 2:18 pm 07 Jan 11

Can’t really give much advice other than to say that my parents had Solahart installed when they built a house nearly 16 years ago. It’s still going as good now as it was then (touch wood!).

Spectra 2:02 pm 07 Jan 11

I am currently comparing Solahart and Edwards.

Don’t spent too long on that – they’re both owned by Solahart, as is Rheem. I’m interested to hear that the Edwards aren’t as efficient, since they’re basically marketed as Solahart’s “premium” brand.

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