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Index of Subjects Hi Bev & All, As in most things, details and method trump labels. And information which comes from a biased source is likely to be biased. Unfortunately the Biomass plant in Cape Breton, based on a video which circulated on Facebook last year, is a model of how not to use biomass. Based on this video, the wood is piled long length outdoors so at best will be sopping wet if dead and high in water if green. And absolutely such plants should be located where the is a use nearby for the waste heat. Excepting swamps, which may take several years to recover from a cut, I understand that leaf area index quickly becomes saturated by the second year. Typically the problem is far too much regrowth which needs to be thinned. Think Fir trees so thick that one must walk edgewise while pushing trees apart. In one area which I had clearcut in 2000 ? ( leaving only the smattering of deciduous trees), when all of the Spruce shed their needles in June, had good leaf cover that fall and in the year after cutting was a riot of shoulder high Solidago etc.; an insect paradise and no light went to waste. It is true that trees fix carbon. But with age, or excessive competition, or site limitations the rate may become vanishingly small or negative if the heart wood is invaded by ants or rots especially if the "growth" rings become vanishingly thin (e.g. an estimated 30 years per cm of radial increment). When rings are much less than 0.4 mm it is difficult to get an exact count. My interest in trees goes back 76 years, when as his partner on the crosscut saw, I talked dad into thinning a largely White Pine grove instead of cutting it to be cleared for farmland. It has subsequently been logged three more times and there is still a dense stand of pine growing like mad. YT, Dave Kentville On 5/11/2019 2:37 PM, Bev Wigney wrote: > David & All, > > I think we have to look at biomass fuel on a case by case basis. I'm > told by those who know better than me, that biomass is probably most > efficient used in systems producing both heat and electricity as in > the advanced biomass gasification plants operated in combined heat and > power mode (CHPs). Those are probably making the most efficient use > of biomass when the fuel is sourced reasonably local to the plant. > Also, it depends on the type of fuel. Clearcutting is considered by > many to be a poor source of fuel as it takes forests out of effective > sequestration mode for an extended period of time. I've provided a > link to a good piece on this on Nova Scotia Forest Notes (see link > below). Some of the other important factors to consider. Much of the > wood being burnt in the biomass power plants is still green and its > energy efficiency is very poor. When you factor in the fossil fuel > used to harvest it, the fuel and general wear and tear on vehicles > used to transport it (often from quite great distances across the > province), and the loss of environmental services of each tree until > its replacement grows to a moderate size, it seems that the logic > becomes rather hazy, at least to me. Then when we consider the > growing market for our forests to be chipped and shipped across the > ocean on freighters to Europe, I truly have to question what good that > is doing from a carbon standpoint -- just think of all the fuel > wasted to deliver wood chips to a plant in the UK or Germany. > Actually, the idea that this could be a "good idea" seems almost > insane to me. > Here's that link - and it leads to some other interesting references: > http://nsforestnotes.ca/2017/01/03/natural-resources-canada-ghg-calculator-confirms-nova-scotia-forest-bioenergy-schemes-are-worse-than-coal-2/ > > bev > > >> Hi Bev & All, >> >> But keep in mind that from a carbon viewpoint it is far better to >> burn wood for power than coal, oil or natural gas. >> >> If climate change takes over then the future for everything is grim. >> >> Yt, DW Kentville >>
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