Solar Hot Water

[BenQld]

Hello

My parents are building a PPOR on the sunshine coast. They are looking into a Solar HWS due to the abundance of sun in QLD. But there seems to be alot of different models out there, and they arent sure which ones would be good.

The main issue is some companies swear by a double ceramic coated steel tank, and others use a 316 Stainless tank. they are looking at having the whole system up on the roof. And this will be their retirement house, so they are planning on being there for a long time.

Does anyone have experience with what brands are good / bad ? and the pros/cons of stainless / Glass coated tanks ?

Thanks

Ben

 

[redsquash]

I narrowed my search to marine grade steel , which is what you need. Either Rinnai beasley or Edwards.

The vacum sealed type are perhaps better in cold climates but our climate doesnt usually get that cold
Will they be in a frost zone.

This will determine the type of collector.

Thermosyphen is most economical and not dependent on electricity. The other types require a pump.
I will send a link with a great discussion on solar hot water late rtonight.

Also search this forum. I don t have this link . gotta go

 

[ggumpshots]

solar hot water systems

http://www.somersoft.com/forums/showthread.php?p=440547

The attachment for Brisbane may help you.

The link below will make you an expert but I think you may have information overload
http://www.solarhome.com.au/?p=78

My belief and brief summary is for Brisbane
Flat plate collectors using a therrmosyphen system are the most efficient and most hassle free way to go.
ie this system uses no pumps and uses the natural heating process of water in the collectors to store hot water.


If you have a storm and your flat plate collector is damaged, it is $1000 to replace . you need at least 2 collectors,
eg small branches flying around in a storm etc.

if you have an evacuated tube or two that is broken, you will spend a $100 or $200 dollars.........so that is a big plus

Evacuated tubes require a pump, thus use electricity.

The evacuated tube isn't as good as it seems , but I would not be upset if it was on my roof.

Also the ET tank is stored at ground level which may be an aesthetic thing for your folks to consider.You don't have a heavy weight on your roof either.

For frost some systems use glycerol eg edwards........ and some use a mechanical system......... eg beasley/rinnai
I believe the glycerol needs to be replaced at maybe 5 yearly intervals, but i never looked into that as a serious option.

Some systems require a sacrificial anode and again replacement around 5 years depending on water quality.
Marine grade steel avoids this .
You and your folks will probably have passed away before the Marine grade steel tank expires.

The most efficient system is Micro solar from Malaysia in my view, but it isn't sold here.

I recently had to replace a system and went for a heat pump . These aren't too different in running costs for a faily of 4 for brisbane, and you can get a $1000 on top of the rebate price you pay if the residence your folks live in will be their PPR.

For 2 people I recommend solar .
In Brisbane the electric booster is on the normal tariff and operates for about 7 weeks between zero hours a day and 4 hours a day depending on sunlight. this is for a family of 4 and a dishwasher.
your folks would use much less

Other tariffs are cheaper but you need to be connected all year round.. which works out more expensive, as you have to pay a regular quarterly fee

Where will your folks retire?
Post more details when you get your head around things.
Some things may be outdated so don't take everything I say as gospel
hope thats a start.
Good luck

 

[BenQld]

My parents are in their mid 50's at the moment, so they plan to be in this house for 30+ yrs.

It is around 500M from golden beach on ths sunshine coast (pelican waters).

I will pass the info onto them about the thermosiphon systems. As I was also concerned if the tank leaked and its on the roof, it could be an expensive job with cranes to replace it.

Also, they were looking at having the solar system with a booster on the night rate power, is this a problem ? how do the normal boosters work ? From my understanding this means that if by the time the night rate power kicks in, if the water isnt hot enough from a overcast day etc, then the booster will kick in and heat it up automatically ? is this a bad way to set it up ?


Ben

 

[ggumpshots]

My parents are in their mid 50's at the moment, so they plan to be in this house for 30+ yrs.

It is around 500M from golden beach on ths sunshine coast (pelican waters).

I will pass the info onto them about the thermosiphon systems. As I was also concerned if the tank leaked and its on the roof, it could be an expensive job with cranes to replace it.

Also, they were looking at having the solar system with a booster on the night rate power, is this a problem ? how do the normal boosters work ? From my understanding this means that if by the time the night rate power kicks in, if the water isnt hot enough from a overcast day etc, then the booster will kick in and heat it up automatically ? is this a bad way to set it up ?


Ben

A night rate is not a problem.

You need to do the math, but My recollection is the cheapest way to go is to use the most expensive tariif.

ie the general tariff.

All the other tariffs have a minimum fee or usage associated with them,
This means you pay the fee but most of the year you are not using any electricity.
Even in the middle of winter you still get a lot of sunlight
You cant just switch willy nilly.
The disconnection and reconnection fees make it not financially viable.
The tank may leak, but 2 men can lift it. you don't need a crane ........I think..well not for my place.
These tanks have a 7 or 10 year warranty and I very much doubt it will leak

The beasley riianni is 330 litre or 480 litre

 

[HandyAndy888]

The "whole system on the roof" thingy is a good idea, until something goes wrong. If it's an older house, it MAY leak into the roof, will be hard to access for servicing if needed, and there will be a big cylinder sitting on the roof. Just my opinion.

 

[Adrian & Amber]

Hi BenQld

We like anything that is environmentally friendly. Typically the true financial benefits from Solar HWS kick in after 7-10 years and on average home owners move every 7-10 years (hence warranties for 7-10 years) however because your parents plan on staying put for 30+ years then it would be a wise investment.

 

[BenQld]

there is no doubt as to them getting a solar HWS or not, its mainly if a ceramic coated tank is as good as a stainless steel one

Ben

 

[redsquash]

The "whole system on the roof" thingy is a good idea, until something goes wrong. If it's an older house, it MAY leak into the roof, will be hard to access for servicing if needed, and there will be a big cylinder sitting on the roof. Just my opinion.

HAndy
If that is your approach then lets hope it never rains !

If you have a flat roof, then leaking into the roof may be an issue but it will quite unlikely be from a leaking tank, but more likely a connection somewhere or cracked collector plates.
For a pitched roof a water leak is a non issue in my books.


There is no choice between a ceramic and a Marine grade 316 steel.

The return on investment will depend on what time frame you do the calculations on.


Are 20 year time frame will give completely different results to a 10 year time frame.


If you assume you must replace a ceramic tank after 15 years then you must purchase and install a new tank for around $1700.
Thats $1700 you still have with a solar tank.
Now a marine grade steel tank can still be going
strong after 25 years and dont need sacrificial anodes.
Just avoid getting sacrificial anodes if possible as then you have the cost of the anode plus th cost of a plumber to replace it if you don't do it your self

As an aside you may also entice tenants to rent your place easier than other places

 

[HandyAndy888]

HAndy
If that is your approach then lets hope it never rains !

Um, lets not forget that a leaking rooftop unit will continue to leak, all day every day....rain isn't a constant silly.