I think the case for renewables beats the case for nuclear. But I think there is a good case for nuclear in preference to fossil fuels - at least as part of a mix, as baseload. Unfortunately the political debate seems to be between nuclear and renewables, not nuclear and fossils. I fear that supporters of renewables are tactically right to oppose nuclear, even if the opposition is not entirely sound as a rational policy.

The nuclear waste problem is far less pressing than global warming. To say otherwise is to belittle global warming.

Both need to be cheaper to be widely adopted. But they are beyond theoretical R&D, we need to learn now by building plant. And we will learn faster with renewables because they have a shorter history. Which technology would we rather develop and make cost competitive worldwide? It has to be renewables - nuclear power could promote nucelar weapons proliferation. So nuclear could be a useful stop-gap measure for the UK and developed countries, including India and China who are already nuclear powers anyway. But for a global strategy, renewables are the best bet.

And we should resist calls for efficiency measures to be seen as an alternative to generation. There is nothing wrong with the efficiency agenda, and good luck to it, but we should still expect increasing demand for electricity, and a crisis if we do not replace the plant due to be decomissioned. We've seen energy problems in the USA, in California in particular, due to the nature of deregulation, and I do worry that deregulation doesn't sufficiently reward the surplus capacity necessary for security of supply. And the efficiency agenda may take our eye off this ball.

How can you belittle the importance of energy conservation like that, whoever you are? Energy conservation must remain a vital part of any coherent strategy to combat climate change.

I agree with the question of nuclear vs fossil fuels. I think that fossil fuels especially clean coal with carbon capture and storage has a part to play while renewables takeup increases to replace all other forms of energy.

Nuclear energy is just too dangerous, especially for developing countries.

Peter Hirst

Of course nuclear 'problem' is less pressing than global warming - it's a 25,000 year (half-life) problem. But that's a weak reason to go for it. All the alternatives - microgen, conservation, efficiency, renewables - are needed together in all major consumer countries to crack global warming. They are all safer and much cheaper than nuclear. And feasible. According to energy guru Amory Lovins (at RMI Colorado) the US could exist without fossil fuels at all - with currently known technology.

Weren't those California energy problems largely due to fraudulent market manipulation by Enron?

At the moment we're as cavalier with our use of electricity as we are with water; it's pretty daft that we use high-quality drinking water to flush our toilets, and we have come to expect an uninterruptible mains supply which we use for storage heating as well as for running sensitive electronic equipment. This needs lots of expensive reserve generating and transmission capacity.

There's lots of potential for being more flexible in the way we use and buy electricity - for example, giving homes a guaranteed, uninterrupted 1KVA supply, and with the remaining 95A capacity being interruptible. This flexibility needs new approaches to metering, but it's now entirely feasible.

Yes, I agree the technology is all there, and getting better, and much is feasible already. We don't have more of it because gas turbine plant is very cheap to build. But if we were willing to pay more for electricity then we could have it carbon free.

And if we produced a surplus, we could begin to tackle energy for transport, whether through batteries or hydrogen. I think we should be ambitious about carbon free electricity, seeing renewables and nuclear competing against fossils not each other.

I don't know if Enron was fraudulent on that particular occasion. Chances are...

I agree that smart metering and smart appliance controls are a good idea and will boost the value of unreliable or periodic renewables.

1kVA is pushing it. Why ration the uninterruptible supply - it is a commodity isn't it? Short-term interruptibility is suitable for functions like heating and cooling, battery charging (charging the electric car overnight), but not for lighting, cooking, or nearly all electronics.

I see no reason to set a goal of making electricity less convenient to use - it suggests we don't care about generating enough of it, that renewables are a bit pants.

Being able to take electricity for granted is a good thing. It means I can sit here and type this without worrying that I might lose it all at any moment. If we couldn't rely on it, this would do massive damage to business and impose great costs and inconvenience on households. I would want to vote against a party saying we shouldn't be able to take electricity for granted.

I didn't mean to belittle energy conservation. But I think its significance in long term strategy is over stated.

Conservation and efficiency measures suffer a law of diminishing returns. Insulate the loft - low cost, big return. Double glazing - higher cost, lower return. Etc.

Demand for energy services will keep going up. Efficiency will cut the energy demand that implies but only a limited amount. You will never light a whole house with 1 watt, because there is rather more than 1 watt of light involved.

There are fairly big gains to be had because efficiency has been neglected. After these one-off big gains are, er, gained, there will only be smaller gains to be had.

Sorry, I didn't mean to imply rationing, just a pricing structure (e.g. via a variable standing charge) that reflects it. In France, EdF have a variable standing charge based on the peak capacity supplied, which ranges from 6kW upwards.

Most homes could manage pretty well with 1KVA, if they had to: using low-energy lighting etc. Most electronics are needlessly wasteful and the difference in power consumption between laptops and desktops shows that the industry can, if the market forces it to do so, make stuff much more efficient. But why bother when the juice is so cheap? (and why bother replacing those incandescent lamps?).

There's also the question of how you'd build the infrastructure for two supplies; in the short to medium term it would probably be simplest to install local battery-backed UPS inside homes rather than running two sets of cables. A 1 KVA UPS with (say) 30 mins of autonomy is a tractable piece of kit which could be affordably leased.

Of course we should be able to take electricity for granted; it's just that we shouldn't necessarily expect to take cheap, copious electricity for granted.

The UPS point is pertinent.

If reliability goes down people will start installing UPS and backup generators and that sort of thing.

A UPS will typically waste a few percent (as high as 15%) of all the electricity going through it. This is a substantial extra electricity demand just for having the capacity to maintain power briefly during a blackout. Manufacture and disposal is probably also significant in environmental impact.

Backup generators face similar objections. I don't want to see one in every back yard, but I would probably get one if my electricity supply became unreliable.

How many people still use incandescent bulbs? Are there any figures?