I have three split-system air conditioners in my house. They don't get used much, and it's rare that more than one is on at a time. Nevertheless when I do use them, I feel a certain amount of guilt. No, not out of environmental concerns (and respondents please don't hijack this discussion into an AGW thread). It's because I know that the true economic cost of running my air conditioner is more than I'm paying. Some of the cost is being paid by people who might like to have an air conditioner, but don't.

How does this come about? It's because, being not totally insane, I tend to run the air conditioner only during hot weather. That is, at the same time as other people with air conditioners run theirs. Together we push the demand for electricity up beyond the level it usually reaches. So there has to be generating capacity in the system that is only used in these extreme weather conditions. The rest of the time, that capacity sits idle. The economic cost of this shows in the wholesale price of electricity, which at times rises into the $1000s per megawatt hour. Yet the price I pay stays the same - the power for my air conditioner is only costing me about $200 per megawatt hour, and that includes the cost of delivering it to me.

It doesn't take a mental leap to realise that the rest must be being paid by other electricity consumers - it's factored into the standard charge for electricity.

During hot weather I cause my electricity demand to rise above the level it reaches at the same time on other days. Constructing a system that allows me to do that has a cost, and I really ought to be paying it all myself, rather than imposing a hidden cost on those not fortunate to have his particularly luxury in life. Technology is certainly up to the task - all that's required is the political will.

Sylvia.

Sylvia, the temp 1 meter below the ground is 19-20 degrees year round.(Sydney). Here is a cheap source of cool air that could be run thru an air-con system.

your analysis into the costs is correct but the horse bolted years ago.

in NSW at least a Maximum Demand tariff was levied on all industrial/commercial users and that was used to build the infrastructure needed for the peaks.

the reasom MD was never used on domestic is basically the cost of metering as the MD meter has to continually monitor the MD in every 20 min period.

to give an example of a building I was "rehabilitating" [as the Energy Doctor] back in 1980, ie Sydney Opera House, the bill was $1.5 million per annum of which a million was for the MD and half a million for consumption [from memory only 1 cent per KWh]. Being in SCC area [as it was called] MD was levied on KW rather than KVA [as in Prospect etc] so SOH had no reason to worry about Power Factor Correction.

After my work in redesigning the control system the bill was halved, which is only 3/4 million then but probably $5 million pa now, with rises in tariffs.

hope that explains why you don't need to feel bad pushing up your own MD. In fact the power plants are more efficient with a good head of steam.

Divorce Doctor,

Certainly the cost of metering would have been an issue in the past. But with the program to roll out "Powersmart" meters, I can't help feeling that there was an option to implement demand monitoring as well. Of course, unless those meters contain this feature and it's simply not being used, then the boat has been missed again, given that many (though I don't know how many) of those meters have been installed.

Part of what bothers me in this is not just the ethics of imposing a cost on those who don't use air conditioners, but also the possibility that the system represents a huge market distortion in favour of electric air conditioners, whereas maybe absorption air conditioners, running on natural gas or LPG, could be cheaper in real terms.

One could also be assured that they won't stop running as a direct result of the blackouts they've contributed to. After watching recent events in SA and Victoria, I've been looking at what it would cost to get a backup generator to run at least one of my air conditioners.

just took a look and this meter is not very smart, it just takes place of former single meters for normal/off peak and adds shoulder

and of course you now choose which appliances to get smart with, ie before your water heater was hard wired to a specific meter

so the way it works is supply authority knows when ITS peaks happen so they give you an inducement to not make YOUR peak at same time [like at 4 cents vs 18 cents off peak/peak], so eg you put on washing machine at times other than air con, so back at power station we get what they want ie a flatter curve to keep equipment happier. It seems meter may be capable of demand measurement but besides you and me the average J Doe would not understand how to make use of it even if a MD tariff was available.

in fact MD is unfair in many ways, eg most chillers get serviced in winter and mechanics run it for 30 mins or so therefore the MD is cooked for that month and maybe a 3 grand increase in bill in june over may all because of the service visit

Divorce Doctor,

It comes as no great surprise that the Powersmart meter is a relatively crude device. It's a shame though, because I can't believe it would have been very expensive to make a meter that tracks usage.

I agree that simple maximum demand metering has issues with it. I was thinking of something that retained enough data to allow a household's contribution to the overall infrastructure requirements to be determined. Thus drawing maximum load during a moderate summer night would be considered to be of no consequence, but that same demand during a hot summer afternoon would definitely affect the bill.

Of course, people would complain that they cannot anticipate the cost of running their air conditioner, but this information could be made available on the web, of via a phone announcement service.