Solar hot water or gas hot water? What do you think is best.

I've currently got a solar hot water heater with an electric boost for the winter months. It's been on the roof since 1977 but last year the stainless steel tank sprung a leak and I had to weld it back up. So I think now is the time to replace it.

Has anyone compared the replacement and running costs to the different systems?

The solar with the electric boost seems a good idea except the cost of electricity is skyrocketing. To tell the truth in the summer the cold water is warm enough to shower in, the hot water being too hot. In the winter everyday we have to use the electric booster. I know our system is old but are the new systems that much better?

That's the trouble with the solar its brilliant in the summer when you don't need much hot water and rubbish in the winter when you need hot most.

Has anyone had experience witha gas boosted hot water system? They are more expensive to buy but how much cheaper are they to run?

I'm thinking of going non "Green" and just get a gas water heater. I've been told they last a lot longer than the other systems and you have hot water whenever you need it. A collegue at work says purely gas actually works out the cheapest in the long run. The new hot water tanks only last about 5 to 10 years (I've seen scrap yards piled high with seemingly new ones) and they are that thin that welding them is now out of the question.

Actually if the gas works out to be the cheapest option this will blow the greenies save the planet and go solar rantings out of the water, as to keep replacing the panels etc must use up more materials.

So do any of you have any experience of replacements?

Keel

Consider a Stebel Eltron heat pump. 305 litres, runs at night on the cheap rate thingy. This summer it cost $22.00 for the warmest three months. In a cold winter, it runs all night but at 2.3 amps this isn't a problem.

Heat pumps work on air temperature and aren't dependent on the sun being out.

The day ours was hooked up the temp was 42 degrees and we had full hot water within two hours.

They can of course be switched over to the day rate circuit but we've never had to yet.

We got ours with a substantial rebate from our local water company.

Stebel are made in Germany. They have a large presence in Australia.

All that said, storing hot water is actually a bit behind the times. Why not consider an on demand gas heater for water?

Hope this helps.

Actually on demand gas is the one I'm leaning towards. Is this system your talking about like the economy 7 we had in the UK? And does it use a solar panel as well?

Keel

Sorry to be late in replying..internet trouble.

As far as I know, most houses (if not all) in Australia have a meter with two tarrifs or indeed two meters. Newer meters have three tarrifs but in any event they should all have a night rate or dedicated circuit which is for hot water only. All the ones I have seen have the electric hot water service hard wired back to the fuse board to ensure that it is only used for cheap rate overnight electricity for hot water.

We had an electric hot water storage/service which even though it ran on cheap rate, (usually for 8 hours from 11.00 pm or midnight depending on daylight savings or indeed power cuts that upset the time clock) at 12 amps was still quite expensive. In Victoria one cannot depend on solar systems in winter so as the water company were doing a deal, we went for the heat pump. Simply put, this is like an airconditioner compressor producing heat from the air but the heat is put into the water. I have uploaded the pdf file which explains it. There is no solar panel component on this system, so you could say there is no "free" heat.

For the January, February, March quarter, the cost of hot water was $22.00. This was running the system at night only. For the April, May, June quarter the cost was $55.00. We don't stint on hot water usage. This was also running the system at night only. Steibel recommend that the system is left powered 24 hrs a day and while this means it would run during warmer hours of the day, at 3 times the rate of electricity cost, it becomes uneconomical.

So, we have it on the night service only (you can switch it over) and it never fails. I have checked with the electricity and water companies and as the unit is for producing hot water, it is perfectly lawful to run it on the dedicated cheap rate meter.

Quite how it manages to produce hot water when running during periods of below zero degrees I don't know. But it does work. The level of insulation is very high so that when demand is low, water does not cool down quckly.

I hope that as it is made in Germany it will have a long life. The reason that standard hot water services fail so quickly is because they are still using a sacrificial anode. In hard water areas that konks out quite quickly.

At my office I use a very small output on demand gas water heater (you can of course get bigger ones). This is a Bosch and runs on LPG. If you are on mains gas, you'd be laughing with this sort of system. Cheaper to install than solar, may well last longer and cheap to run.

You can get large on demand gas systems, you can even get them where the cold water runs back to the heater and ciculates until it gets hot, then it is delivered to the tap. It's quite spooky turning on the hot tap and waiting for a few mins, then hot water (at a pre-determined temperature) comes out of the tap!

All this info is on the interweb and other companies make the heat pump water systems.

You probably get more sunshine hours in Perth than I do here but whatever you do, I'd check with your local authority, water company or even state government to see what rebates are being offered to encourage replacement of older systems.

I'm no greeny but I'm all for putting more money in my wallet than the power company's.

I hope this helps, feel free to ask if you need more.

I forgot to mention, the heat pump system shown in the pdf file has an electric element back up, but I really think you'd find that you don't need it. Our model doesn't have one fitted.

Cheers Alistair

After I'd repied to your replyI googled the heat pump it looks good. I'll look into it a bit more.

The gas is also looking good.

But the cheapest option, with rebates is the solar which in my view is more damaging to the envionment in the long run.

Keel

It's quite a decision to make. However, it's all out there to find. Bear this in mind though: To produce any given result requiring energy, the cost is the same in ENERGY consumption terms regardless of how you do it. Einstein had a bit to say on that. For example, wind turbine blades are made of acrylic, in Mexico. So wind energy may be "kind" to the environment but it has still cost the same in energy consumption to produce the end result. Plus, the acrylic production process has enough toxic emmissions to wipe out a small country.

There is actually no such thing as green energy. Even solar has production implications and disposal implications.

Actually Keel, I know you know all this...just hope a few who have been hoodwinked by the green propoganda get to read this!

I wasn't having a go at the green propaganda about the limited lifespan of the solar systems but more of the corners cut by modern production practices. However this is fed by the green lobby and rebates.
If there were no rebates then all the systems would have to stand or fall on their merits and at the moment solar doesn't stand.

The systen I have now has proved it self for 30 odd years and is envionmentaly friendly, the replacements are not. So were now 30 years on and less green.

Keel

That's extremely interesting, I wasn't aware of that. Thank you.

Gas.

We have instantaneous on bottle gas and it uses less than 2 bottles a year( family of 4) but the benefit is also in the use, always hot, digital read out of temp so no more 'playing with the cold tap' just set and jump in/under!

Ours is a Rinnai 26+ and will easily run 2 showers at the same time.

G.

i have solar but i'm not on main gas

renewed mine 2 years ago...cost 3000 dollars

Hello Sam

I havn't seen you posting for a while.

I know with rebates the solar works out the cheapest but how much cheaper is your new system to run compared to your old one? (I'm assuming you replaced solar for solar).

I'm swinging towards an instant gas heater for the convenience and possible running cost savings over the electric boosted solar. What do you think, do you boost yours much in the winter months?

I've got my ticket booked for Metallica in November, any chance of a lift?

Keel

you could if i had tickets but not going.... sorry

i am going to Guns and Roses at the motorplex in Dec if you need a lift!

I don't know the details but I believe that electric boosters have got a *lot* better in the last decade - certainly a lot better than the old crap. If the electric part of your system is as old as the 1970s stuff, it might be worth looking again at the new technology before you decide to change completely.

oh to answer the question

ours is much more economical with the new one..... when its really cold at night, switch on for half hour in morning...enough hot water for couple of showers..... doesn't have to be a warm day so long as sun shines...no switch

if not sunny....then switch is on no more then 30-40 mins if having showers later at night

hope that helps

I saw them in 92 at Gateshead stadium. I would have seen them again but since Axl threw the toys out and lost all the original members I'll give it a miss.

I got the new Iron Maiden CD today for fathers day. Did you know their coming back to Perth in March?

Keel