Huhne plans 32,000 more wind turbines

[doodab]

Who cares about efficiency when the source is renewable? We need both electricity and heat, with the energy given in those forms who cares about current efficiencies when considering harvesting heat from a cell? Other methods exist and not all include the medium of a copper conductor.

If your storage system is only 50% efficient you need to harvest twice as much energy in the first place. Although it might be renewable energy it's only harvestable at a finite rate so efficiency of the storage system directly impacts capacity. I expect building twice as many windmills would cost more as well.

Heat needs to be in a harvestable form. Any heat you cannot either transform or use directly is wasted. To be used directly it needs to be generated close to where it will be used i.e. in people's houses. This implies some people will have too much and some too little, and it's not easily traded so will need to be either stored for later or wasted. The temperature also needs to be high enough to actually heat stuff up and it needs to be controllable.

When comparing the engine of car you'd be lucky to achieve 40% efficiency.

Yes but i'm not suggesting we use internal combustion engines to store energy for later use am I?

Would not be suitable on a large scale though.

Exactly. We are talking very large scale.

Incidentally the process does not need to be 100% efficient, who said it does btw?

Nobody said it needed to be. You said it was. Obviously more efficient is better for the reasons given above.

You seem to think nobody is thinking about this stuff but actually lots of people are.

[scooterscot]

If your storage system is only 50% efficient you need to harvest twice as much energy in the first place.

That's a rotten storage system, whether kinetic, chemical, or electrical - 50% is rotten.

Heat needs to be in a harvestable form. Any heat you cannot either transform or use directly is wasted. To be used directly it needs to be generated close to where it will be used i.e. in people's houses. This implies some people will have too much and some too little, and it's not easily traded so will need to be either stored for later or wasted. The temperature also needs to be high enough to actually heat stuff up and it needs to be controllable.

This is the A>B technology gap that irritates. If the technology does not exist the idea is flawed. Can we continue to be so complacent about energy conservation? I hope not.

Harvesting Heat - Technology Review

Yes but i'm not suggesting we use internal combustion engines to store energy for later use am I?

Good chance you've already done so today, that's what the alternator under your bonnet does.

Nobody said it needed to be. You said it was. Obviously more efficient is better for the reasons given above.

No I did not. And yes it is. However if you're only harvesting one form of energy efficiency is obviously reduced. Energy is only borrowed.

You seem to think nobody is thinking about this stuff but actually lots of people are.

I do not believe that or else many installations would have not already taken place. I do think however there is much resistance to change, inventiveness. And that's sad for me in a country where so many inventions that the world now depends should replace creativeness with critics who's only contribution is hot air and noise pollution.

[doodab]

That's a rotten storage system, whether kinetic, chemical, or electrical - 50% is rotten.

OK. So now you agree that a storage system creating hydrogen via electrolysis then converting it back via fuel cells is a bad idea. That is at least a start.

This is the A>B technology gap that irritates. If the technology does not exist the idea is flawed. Can we continue to be so complacent about energy conservation? I hope not.

Harvesting Heat - Technology Review

This is the reality gap that I'm talking about. If we can't actually make it, it's not going to work. I'm not saying we can't invent something new, but we do have to apply the laws of physics to whatever we invent.

Those thermoelectric modules are about 5-10% efficient, so taking the top end of that and also using the top end figures of 70% efficient electrolysis and 80% efficient fuel cells that will improve the overall efficiency of your energy storage solution by about 1.4% for an overall efficiency of 57.4%. A more realistic 60% efficient fuel cell will give you about 45% efficiency through the whole cycle.

30% of the energy is wasted during the electrolysis, so we need to improve that as well as invent new ways of harnessing thermal energy that will otherwise be wasted. Genuinely new technology is required, we simply don't have something that will do the job at the moment.

Good chance you've already done so today, that's what the alternator under your bonnet does.

I don't have a car. In fact, I haven't owned one for years.

No I did not. And yes it is. However if you're only harvesting one form of energy efficiency is obviously reduced. Energy is only borrowed.

This is the technological intellect barrier I'm on about. Fuel cells are 100% efficient.

60% generates electricity

40% generates heat - think of an grannies that might like such a thing?

Erm, yes you did, and it seems you cannot tell the difference between efficiency and the law of conservation of energy.

I do not believe that or else many installations would have not already taken place. I do think however there is much resistance to change, inventiveness. And that's sad for me in a country where so many inventions that the world now depends should replace creativeness with critics who's only contribution is hot air and noise pollution.

If anyone is contributing hot air and noise pollution it's those who offer their ideas as possible solutions without performing any sort of quantitative analysis on them. Performing that analysis isn't simply naysaying by those resistant to change, it's exactly the sort of application of science and engineering to the problem that you are calling for. There is a big difference between something that works in principle and something that works well enough to be worth implementing on an industrial scale. It makes sense to ensure we have the best (or at least close to) solution before we commit our future to it.

FWIW, that book I mentioned suggests that a large part of the storage problem can be solved by electrifying personal transport. Millions of electric cars on the roads will mean large amounts of efficient energy storage (LiPo batteries are about 99.8% efficient over the charge/discharge cycle) able to absorb peaks in the supply.