I agree that gas is not a good change, at least not LPG (and what "passes" for supposd ly 'natual' gas. We could easily have massive sources of methane if we simply composted our own waste (sewage) as is done in parts of Luxumberg.

BUT

The largest impediment to Australia being a far more "Green" country with far less expensive and destructive energy systems, is intentional DISINFORMATION and GREED, even by our own politicians

Caring about the planet is LIED ABOUT - supposed to be bad for the economy, bad for business & bad for jobs - but it is good for all of those things.

BLACK ENERGY IS NOT CHEEP

It kills. The things that are made from crude (our toxic stew of household junk) are now PROVEN to be heavily involved in our new illness pandemics (cancer, altzheimers, ADHD, Autism, Parkinsons...tons of autoimmune stuff) .causing expensive illness, expensive disability pensions for life & putting lots of smart productive people never working again ever.

That is very expensive energy.

For what we pay in petrochemical toxic related disability pension and surgeries, we could go nationwide to all renewables several times.

For the cash spent on 2 US wars for oil in Iraq (and a ten year blockaid costing over a million deaths)+ cash unaccounted for in their (ha) rebuild of Iraq (stolen cash) they could have replaced their whole energy infrastructe several times....but never would.

Kids are much louder than the edson heat pump. Also I have a number of 800watt in /3600 watt delivered panasonic reverse cycle air conditioners for my heating and they are whisper quiet.

Peter Struys says that the COP will be more like 1 when temp is below zero.   While it's certainly the case that COP decreases when ambient is low, the implication that the working COP might be about 1 in Australian working condidtions should be refuted.   I own a Quantum system which has a COP of 1.69 at 0 Celcius.  So in my book the heat pump hot water system makes emissions sense, especially when the consumer buys Green Power.

Liam Ryan has suggested that it is common for heat pump hot water systems sold in Australia to incorporate resistive heating elements.  While this may be true for the Rheem system, it is certainly not true for the Quantum system that I own.  I have spoken to the technical director of Rheem and he stated that the use of resistive heating elements in heat pump systems was the exception, not the rule.

Matthew, the European models may operate in the extreme temperatures but the Australian models switch off the heat pump at temperatures below 5°C and rely on the electric boost element.

The models available from the major Australian suppliers (Rheem, Edwards, SolarHart etc) have rated COPs under 4 at 30°C, and COPs under 3 at 20°C. All include electric boosting.

One of the primary causes of increasing electricity consumption and CO2 emissions in Australia is the ever increasing use of air conditioners (heat pumps). The argument that heat pumps somehow reduce carbon emissions is a fiddle and a play on words. Most people in our hot climate use these devices for cooling NOT home heating. Generally speaking that means during times of peak electricity demand when renewable electricity has limited availability (morning and late afternoon). That means their power comes from coal and "peaking" gas fired electricity.

Increasing power prices are primarily caused by the need to spend massive amounts on infrastructure and new generating capacity to meet the increasing peak demand which these so call "renewable energy" appliances are subjecting the network (AFR p.1 Tue 8th Feb 2011).

Distributed power generation using gas (or even better bio gas) is an accepted solution in countries that have a clear plan to tackle climate change. Why not here in Australia? Becuase our Government is obsessed with trying to pick winners rather than creating policies which encourage innovation, entrepreneurship and long term thinking.

"Heat Pumps for Hot water (which I would argue should be combined with Evacuated Tube Solar) are on the market..."

I'm looking at installing Evacuated Tube Solar in the next year or so, but this is the first I've heard of this particular notion.  Do you know of anyone offering such an installation as an integrated (heat pump + ETS) unit?

Panasonic, Daikin, Toshiba, Mitsubishi Heavy, Mitsubishi Electric, Samsung, Fujitsu http://www.eheatgroup.com/Swedish_Energy_Agency_heatpump_test.pdf "The EN Standard for air-source heat pumps has set -15°C as the lowest test temperature. At this test the heat pump was also tested at -18°C, where Panasonic E9EKEB achieves COP 1.8 In fact eco-cute models in Japan (CO2 as refrigerant) are designed for -20C suitable for deployment in the Hokkaido region in north Japan http://www.r744.com/articles/2008-02-01-high-efficient-ecocute-models-la... I do agree we should have serious MEPS, Minimum Energy Performance Standards and policing to weed the rubbish out, but the units I am proposing that we use are made in the millions and readily available at an affordable price. Heat Pumps for Hot water (which I would argue should be combined with Evacuated Tube Solar) are on the market, and all the common models that I know of in the Australian market DO NOT use an electric resistance element for boosting. New CO2 (as working fluid/refrigerant) units go down to -30C before they crossover the 1.0 COP threshold.

Yes, I agree! After having started in the Netherlands a heatpump-import company after the policy's were finally implemented concerning low temperature-systems for houses, that Sweden already implemented in the 1970's. Perfect for the very efficient groundsource heatpumps!
Use these systems for home heating & cooling and produce warm water, and ensure regularly a boosting temperature to get rid of the legionella-bacteria in the warmwater tank. All proven in market-products in 
Europe. Buffer the season's excessive energy in the ground, and create a nice comfortable efficient home, always the same temperature. These heatpumps are suitable to switch on and off if electricity supply needs that. With a solid building-mass you can easily buffer in that mass or the tank of water!

The Economist recently hosted an online debate on the motion "that natural gas will do more than renewables to limit the world's carbon emissions."  It's interesting to see how audience opinion evolved over the course of the debate, here: http://www.economist.com/debate/overview/193

All very intesting Mathew - but you ignore the huge detrimental impact that the installation of low quality air conditioning is having on delivered energy charges for customers - not only are we using far more electricity (NSW broke it's record demand last week), but we are having to pay vast sums to build the required network reinforcements for these peak periods. These network upgrades are the real reason behind higher electricity costs in the eastern states, and there is a very close correlation between increased air conditioning driven demand and higher prices for consumers - not all a good news story.

Highly efficienct, good quality embedded generation is a pragmatic first step in lowering the CO2 intensity of our major load centres.

As some of the commenters have pointed out, if ambient temps are very low, then air-sourced heat pumps may not be less greenhouse intensive than gas.

However, the point remains that it's possible to generate zero-GHG electricity.  While it's possible to create zero-GHG gas, I suspect it would be less efficient overall than using electricity.

What this suggests is that, if we are serious about reducing GHG emissions, the coal-fired power stations must be closed down in the next decade or two - particularly the brown coal ones.  Whether the replacement will be solar thermal (as advocated by BZE), nuclear, other non-fossil sources, or all of the above is a question that needs to be answered sooner rather than later.

In the meantime, gas hot water is almost certainly a better option than resistive electric hot water.  I'm with Liam Ryan - conventional electric hot water should be banned, but that's only one small part of a strategy to improve energy efficiency.

Now Matthew, if you really believe that natural gas was no good, you shouldn't be promoting technologies such as technosolar renewables which depend utterly on natgas for backup.

I am not sure anyone has claimed gas is "a solution" to climate change, rather a transitional fuel. Although transitional between coal fired generation and what, I'm not quite sure. One thing is certain, renewable energy can never supply 100% of demand regardless of what the WWF seems to think. On a more practical note, heat pumps, while they might be eco friendly in terms of emissions are still very poor in terms of noise pollution. In a society in which we live ever closer to our neighbours, it is an important consideration and one that saw me choose gas over a heat pump.

The COP of a heat pump system when the ambient temperature is below zero can be more like equal to one.

The problem is when you need the heat the most the system is at its least efficient

The argument about heat pumps and gas fired heating/power plants is not binary. Where a building does not have access to natural gas, an air source heat pump is a good heating solution. But beware COP is not a static measure of efficiency. It varies dramatically with external ambient conditions, generally between 2.5 and 4 with seasonal (summer/winter) ambient temperatures the key. A ground source heat pump will generally give higher average COPs as ground temperature is subject to less season temperature variation, but these are much more expensive to purchase/install.

Power or heating/cooling from gas ALWAYS provides low emissions regardless of seasonal variations.

If Australia's carbon emissions were 230g/KWh we would be one of the world's lowest emitters rather than the world's worst!!

We are blessed with an abundance of natural gas which can be used to reduce emissions today. In the not too distant future the gas delivery infrastructure can be used to deliver renewable biogas (methane) from waste which can still be used in today's appliances. This isn't a distant dream, the Germans already do this, they even mix in some hydrogen made from wind and solar energy!

The central premise of this article is that heat pumps are less greenhouse intensive than gas fired hot water systems. This is simply not true. The heat pump COP of 5 used in the back of the envelop calculation is actually more like 2.5 or lower when factoring in that the boosting in heat pump hot water systems comes from conventional electric resistance heating.

The benefit of air-sourced heat pumps over gas hot water with the current emissions intensive grid is nominal at best. Over the life of a hot water system bought today (15 years) this is not likely to change significantly. The efforts of BZE would be better spent "educating"  (lobbying) for a ban on conventional electric hot water.