I wonder how many times I'm going to see the same naive ideas trotted out as being the solution to the world's energy problems.

Alchemist, the problem with having windmills and solar power generators on individual properties is not that it is impractical, but that it is too expensive. The resulting power costs much more than it does from your electricity retailer, because of the opportunity cost of the windmills and solar generators. BTW, you left out the batteries and other backup systems that are required for when the wind isn't blowing and the sun isn't shining.

An opportunity cost is real money that people can't use for paying off their mortgages or improving their standard of living.

The reason we face an environmental issue at all is exactly because coal fired power generation is so cheap. Perhaps that's not very surprising - coal is a concentrated energy source that you can just dig out of the ground with big shovels, it's easy to handle, and to get the energy out you just burn it. This means that moving away from it almost inevitably involves paying more for power.

Electric cars don't help at all. The energy they use still has to come from somewhere. Hybrid cars are more energy efficient, and as the technology becomes cheaper, and petrol becomes more expensive, I'm sure we'll eventually see more hybrids on the roads.

Biodiesel in interesting, but I couldn't find any information on how well it scales. In particular, how much water is required to grow the feedstock?

In short, most of what you've proposed is not a solution at all, and it's just as well you didn't get to implement it before some basic economic analysis was applied - it would have been a hugely expensive mistake.

Sylvia Else.

Once again you're talking sense Sylvia. I have solar panels which cost big bucks even after a greenhouse office subsidy but which still require very frugal energy use. For example I grill food in special microwave bags. I also make some biodiesel out of used cooking oil from chicken shops that ends up costing about 50c a litre without costing my time or paying the required 38c per litre excise. One estimate says we need 16 hectares of good land to grow enough oilseed to make biodiesel for one car plus a share of the farmer's tractor use. An alternative diesel technology is thermal conversion of various intractable organic materials but this won't power 700 million cars. Ditto ethanol. Basically something has to give in a very big way.

It is clear that we have to find economic alternatives and it is clear that we have to change the behaviour of people. Rather than looking for particular alternatives (which will come of their own course when they are cheap enough) we have to find ways to

Change the behaviour of individuals so they make energy saving choices through economic incentives.

Change the system so that the "better" alternatives in terms of total energy used for energy out have incentives when it comes to getting investment dollars.

Coal is good from the energy standpoint because the energy required to produce electricity is a lot less than energy we get from it. It just has some unfortunate side effects. It is very sensible to be looking for ways of reducing the side effects of coal - perhaps by someone finding a good way to get the energy without producing green house gases. However, someone has to pay for finding out how and so we need to change the system of capital allocation so that it becomes attractive for innovators to figure out how to achieve societies goals.

For example solar panels are probably not the answer at the moment even if they were cheap to produce because the total amount of energy required to produce solar panels is probably greater than the energy we will get from them when we consider the total energy consumption to get energy from them. Add in the cost of batteries of erecting them, of transport to houses etc. and you get little if any extra energy. Solar panels will probably have to wait until we get ways of constructing them onsite from local materials.

Rather than trying to guess which way will work best we need to change the economics so that it will happen as a matter of course.

Federal finance minister Nick Minchin has said that there is no economic case for nuclear power.

He's right. There isn't. Australia can go on burning coal for as long as it lasts. Indeed, doing so won't have much impact on global warming, because we do not represent that big a proportion of fossil fuel burning. If there is a global warming issue, either the rest of the world will address it, in which case we'll have no problem, or it won't address it, in which case nothing we could do would really help.

So the first question Australia needs to ask itself is whether it's willing to cooperate in a global push to limit (and indeed reduce) CO2 emissions, of prefers to follow the cheaper path of letting everyone else bear the costs.

But could we get away scot-free with doing the latter? One danger in pursing that course is that it makes it very easy for protectionist governments abroad to justify tarif barriers against us by calling it an imputed carbon tax on our exports. It could also result in anti-Australian feeling caused by our perceived (and indeed in that case actual) parasitic behaviour.

This is a world problem. We need to be seen to be playing our part - for our own sake.

(BTW, Fickle Pickle, my comment about the energy in coal was a simplification for the purposes of discussion. In reality, the energy exists because oxygen will react with carbon in a way that produces heat, and which results in CO2. The only reason oxygen is available so readily is that plants have previously separated it from CO2, by using the energy collected from sunlight. It is implausible on chemical and physical grounds that a process could be found that has a net production of energy from carbon, but which does not produce CO2 in the process. Sorry).

Sylvia.

I think we about to begin a Decade of Dithering and Denial with coal. People on diets eventually realise they have to abstain from cream cakes even though they are cheap. Just before his resignation Deputy PM John Anderson seemed to grasp the contradiction between urging more coal exports and the long dry spell in SE Australia. An imputed carbon tax would never fall on coal exports directly. In the TV ad the shop assistant asks 'what do you want the environment to do with this plastic bag?' We could ask China 'how do you propose to sequester the carbon in this shipload of coal?' Within a decade there will have been many extreme weather events and the much touted 'clean coal' technology will probably be as credible as the missile defence shield. Therefore I don't see a coal slowdown til maybe the year 2020.

Putting individual systems on each house, may sound expensive, but it would create jobs, start up new small industries and put Australia at the forefront of sustainable energy. I have been using this system for many years and on average generate between 2 and 5KWA per day depending on the day. I recovered my costs within 6 years and until a year ago used a small diesel that powered a 120amp 24v alternator that used 1lt every 6 hours, that was driven by biodiesel and costs me 18cents a litre to produce. Now I use a system that consists of 3 flywheels, drive by a 12v wiper motor, driving a 35 amp 24v alternator. It took a bit of getting going but once running it produces twice as much power as it uses, giving me a constant return of about 20ah. In more than 1 year it has not stopped, going 24/7. But I understannd that people can't see beyond economical rationalism and how things were done in the past. I believe that we are at war with the problems we have caused and if we continue to try and solve things with outdated thoughts and technologies then in 5 years time, we will be far worse of than now. What you fail to remember is that our environment is past breaking point and unless we take radical and differenmt steps now, then society as we know it and our lifestyles will dissapear. We could have biodiesel plants set up in every capitol city and in major regional centres, producing within a year. You can't do that with any other forms of energy production. I listened to Saul eslake on the radio the other day, and believe it or not, but his solution, wait for it, find more oil and look at alternatives. Wow, now thats progressive, if you want to do nothing but go down the same road. But then again have we ever seen anything constructive come from economists. Please don't hold your breaths.