For the past few decades, solar hot water has been seen as the province of backyard DIY renewable energy tinkerers, keen environmentalists or of those folks with bigger piggybanks than most.

Not any longer.

Due to building regulations, solar hot water has moved firmly into the mainstream and the combination of government rebates and juicy Renewable Energy Certificate prices mean that BREAZE members will soon have access to solar hot water units that replace their current systems at no cost.

The link between human generated greenhouse gas emissions and a heating globe is now pretty much the scientific equivalent of a lay down misere.

Therefore, BREAZE is keen to promote technology that can displace carbon-based emissions and put common sense, renewable energy solutions in their place.

Solar hot water does an excellent job of this, even in cold, old, gold Ballarat.

Heating hot water accounts for about 27 per cent of an average household's daily energy use and electric-boosted hot water systems are fossil fuel gluttons, creating up to 7.5 tonnes of carbon dioxide in a year, or 150 of those spooky looking black balloons.

Most electric systems are set to boost their water overnight to take advantage of off peak electrical tariffs.

They still use the same amount of coal, however, and families with an additional boosting unit to cover any hot-water shortfall during the day pay a much higher day tariff, along with creating more carbon dioxide.

The emissions profile of gas-boosting hot water is substantially "cleaner" than coal-fired electricity, but with a longer time frame, the emissions and cost savings make augmenting or replacing a gas system still well worth doing, financially and atmospherically.

Our family's gas bills indicate that before installing a solar system nine years ago, we used an average of 83 megajoules of gas a day from November to April.

We now use 3MJ.

There are two payback periods.

Firstly, there is the financial one.

Now that solar systems are cheaper and more efficient, the payback period, where your energy savings overtake your initial cost, is also quicker. Interestingly, people rarely stop to pose the same question of existing fossil fuel based systems, which will of course never pay for themselves.

The second payback period refers to embodied energy and this concept also goes some way to answering the following question:

"Why replace a perfectly good - albeit fossil-fuel based - hot water system and waste it, along with the embodied energy it has taken to make it?" Actually, the first answer is that you don't have to.

There are good rebates for retro-fitting a solar collector to an electricity-based system, or pre-heating your current gas-boosted system.

However, the generous $2500 Victorian Government rebate that is ready to roll from July 1 is paid if you replace your current system entirely.

Is this wastefulness wise?

Well, here come the sums . . .

If your current electric-boosted system spews out 38 tonnes of carbon dioxide over the next 5 years as you wait for it to die of natural causes, then it's probably better to euthanase it immediately.

Not only will it take 29 megawatts to run over 5 years, but as solar hot water systems have approximately 4MW of solar heat gain per year, they pay back the original embodied energy it has taken to make them within a couple of years and then go on to theoretically offset the embodied energy of the system that was replaced several times over.

And the original fossil-fuel system only ever used energy, "paying back" precisely nothing.

Which system is best?

As an independent community group, BREAZE believes that basically all the systems do a thumbs-up job of heating hot water.

BREAZE has managed to negotiate a fairly lucrative membership discount for its members with a supplier, in order to roll out this solution en masse.

Fundamentally, however, BREAZE doesn't care what solar hot water system people buy. What matters is that they actually get one.

Heating water via the sun instead of from electricity pushed up from La Trobe Valley or gas from Gippsland is such a no-brainer.

University of NSW researcher Mark Diesendorf has modelled a renewable and energy efficient future scenario in order to turn around our heating atmosphere.

The modelling assumes virtually all Australian homes have solar hot water systems.

But with solar hot water sales running at 5 per cent of national water heater sales, we need bridges to the remaining 95 per cent.

Otherwise our water won't be the only thing that we will be heating.

*Nick Lanyon is president of Ballarat Renewable Energy and Zero Emissions.

Article Sources:http://ballarat.yourguide.com.au/news/local/news/general/solar-demand-needs-to-heat-up/774795.aspx