Posted By: renewablejohn
I am disputing that. We have some shocking thermal efficiencies at some of our largest thermal plants which can easily be beaten by small chp plants even down to the micro chp level. The sooner these dinosaurs are pensioned off the better.

Well, yes a new plant should have a better efficiency than an old one, but that's comparing apples and oranges. If you consider two thermal plants of equal age and using the same technology the larger one will have better efficiency. That's just physics.

However, the reason we've traditionally had large plants is only partly to do with that. Another main reason is that if you're using a relatively bulky fuel it's more efficient to put them close to the fuel source (ie: a coal field). However, if you're using renewables or a fuel source that's either decentalised or easily piped about then that becomes much less of an issue and you start to see the benefits from locating generation close to consumption tipping the scales the other way.

"quote" Robin B (can't seem to paste)
Who has got it sussed?

I went to the Ecoisland Global Summit last week on the Isle of Wight (where I gave a short talk on what our Transition Town is doing) - I've been fascinated by their journey since they started talking about ecological footprinting years ago. Best Foot Forward have been working with them. Crucially they are putting together a 'Greenprint' (masterminded by David Green) looking at decentralising energy and are running a number of major projects. These include a fascinating hydrogen refuelling centre for cars with either a fuel cell or ICE converted to run on hydrogen. It was very impressive. IBM showed a demo on how to remotely switch off individual power sources to ease demand spikes.

They have several key 'big businesses' involved, partly as they realise their CSR needs attention but also as its great fun to be involved in pioneering. See http://www.eco-island.org/hub & a film of the event, including a statement from the Energy Minister but more inspiring was the introduction from David about the whole concept. http://www.ecoislands.org/ (click on 'watch')

Posted By: ecohomeICE converted to run on hydrogen

I'd be very wary of this. Hydrogen embrittlement is an issue for some high-performance steels. I'm sure you could design an ICE to run perfectly reliably on hydrogen, but I wouldn't like to say that one designed for petrol or diesel would be ok.

If you want to use hydrogen then just use a charcoal slurry mix of 50% water and 50% charcoal. Yes you need different injectors and hardened piston rings but it is still easier and more cost effective then producing and compressing hydrogen.

Posted By: SteamyTea

Posted By: renewablejohnIf you want to use hydrogen then just use a charcoal slurry mix of 50% water and 50% charcoal.

What does that mix do?

Can be used in a slow running diesel engine as a substitute for diesel for electric power generation. Advantage over diesel is that it is renewable and has lower Nox levels

Running a car might not be an option as engine RPM is normally around 400 to allow for slower combustion rate of the fuel although speeds upto 1800 RPM have been achieved. Pumps where not an issue but modified injectors and hardened piston rings where required due to lack of fuel oil lubrication. Added benefit on running on water is a cooler engine with steam evaporated prior to charcoal combustion. Original technology was developed for coal slurries fired in diesel engines.