Posted By: tonyhow do you define carbon emissions?

I would define them as streams of carbon being added to the biosphere (atmosphere, plants and animals, top-soil, top few hundred metres of the oceans, etc).

belting out CO2 (and pollutants) from a chimney and calling it zero is not right

Indeed, it wouldn't be. Is there any indication that that's happening here? They say a reduction of 45% which seems plausible to me. Basically, you lose the roughly 60% wastage of a non-CHP plant (up the cooling towers) but use a smaller so probably slightly less efficient generator instead. Sounds roughly plausible to me.

and do the health costs get added into the cost side?

I assume you mean the local health costs of emissions from the plant? With gas power (as used in Aberdeen) that shouldn't be too much of a problem, I'd have thought.

I like the idea of reduced cost but would prefer to see reduced energy use.

I too like reduced cost. However, is see little benefit to reduced energy use as such - only reduction in the harmful effects of harvesting and transforming energy. Using a bit less energy but getting it from a more harmful source is not a win.

The downside to schemes like the Aberdeen one is that they're building new largish infrastructure based around better but still far too high levels of carbon emissions. The upside is that at least the technology to do the basic energy transformation is fairly centralized so future replacement can be expected to be a quicker and easier process. I hope they've designed the purpose built buildings with this in mind.

Any more info to allow an informed opinion to be expressed, Will?

No sorry, I just pasted the text off their website. I'm not on this heating network, no connections to them, etc etc. I just drive past it each morning.

IIUC the concept is to link the hetaing systems of a large Academy (secondary school) and several swimming pools, to supply heat to the tower blocks. The comment is made that the heat demand profile of the school/pools is different from the flats, this allows the CHP to run for more of the time. Linking together all these heat systems gives resiliance/backup if any one of them is broken down.