Carbon neutral wood chip boilers

[sandsnakes]

Intersting article on using woodchip boilers as a green, carbon neutral heating source.

http://www.theecologist.org/archive_detail.asp?content_id=1041

Sandsnakes

 

[Ogri the trog]

I've not read the article, so I may be commenting on things that have changed a lot....
I was looking at a range of woodchip boilers at the Royal Welsh Show this year.
All very promising and green, right up to the point where the guy says the chips are being imported from Scandinavia - like Wales doesn;t have enough wood of its own!

Ogri the trog

 

[EdS]

othe problem is if it takes of the wood will come form commercial monoculture short rotation coppice (willow) that is cut on a 3 -5 year cycle.

Better than many crops though.

 

[gregorach]

I'm not sure what your objection to SRC is, EdS? It's an extremely efficient form of production, and an expansion of SRC would almost certainly result in the expansion and protection of some very important habitats.

However, some caution certainly is required. After all, one of the main drivers for the development of the coal industry in Britain was the shortage of firewood...

I'm also curious as to how these boilers stack up against a modern masonry stove in terms of efficiency.

 

[British Red]

I'm looking seriously at wood fired heating and cooking right now. The seasoning of woodchips doesn't concern me but the infrastructure to make the chips and run the boiler makes it a non starter from a "self sustaining" point of view - its too dependant on electricity and fossil fuels.

Still looking forward to growing our own coppice wood and using a more converntional wood fired range though.

Red

 

[EdS]

the field behind my house has a couple of acres of SRC willow and the estate has 18 hectares, and I used to work supplying composted sewage sludge for all the SRC willow that was meant to be going to the Arbre power station. There is not as much wildlife as you would expect in the willow - not even birds nests.

Also yields where no where near the expect tonnage. there was also problems harvesting it - it has to be cut in winter but the ground is too wet for the size of harvester required to cut 3 years let alone 5 years growth. The vehicles left really deep furrows and kept breaking linkages.

 

[gregorach]

Well, that's disappointing...

 

[British Red]

Yep, I've heard similar tales. I'm erring towards 7-9 year coppice cycle on ash and hazel.

Red

 

[Tourist]

I know its not wood but what about the boilers that burn straw, are they any good.

I did the C&G Plumbing and Heating a few years back but they only cover gas boilers, not even oil anymore. My own interest for a virtually zero impact is the use of ground source heat pumps, I have seen these used in the USA and they seem good. You can use a couple of small photovoltaic panels to power the electrics and away you go.

 

[EdS]

but we did really impressive results for Miscanthus (elephant grass). It was assumed that it would not grow well this far north. On the 0.5h area we trialled we a pretty good yield after 2 years from planting the rhizomes - give another year or so it would be viable.

 

[Tourist]

How much area would you need to produce grass for all year round domestic use?

As a point of interest, not heating but cars, I read that to produce your own veggie fuel for a years average motoring use you need 25 acres.