Biomass – a burning issue

[SimmondsMills]

This is the place to give us your feedback on the Biomass paper

[KATE DE SELINCOURT]

You can now see the paper, and the associated press release, at https://aecb.net/new_releases/

Please read the paper before posting responses as a number of people have admitted to responding first.

[Tom Foster]

Lively discussion kicking off here http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6241&page=1#Item_2

[SimmondsMills]

“fallen trees/branches, timber not of sufficient quality, and waste.”

I understand that timber and even bark can be used in manufacturing wood fibre insulation boards (eg pavatex/therm and the like). Not sure of the exact quality limits for the material.

I love fires – but opted not to rely on a woodstove for our nr. passivhaus refurb in hereford due to the air pollution aspects in town. Wish others would bear this in mind, as all sorts of crap is burnt locally (apart from one sweet soul, who burns properly seasoned fruit wood.mmm)

Got a nice picture (which I will post some time) of me and my wife having an outside evening fire (in Chiminea) just outside the house, with the smoke going up past the MVHR air intake and dirtying the intake filter in the unit (turned th eunit off for the evening because of this, and no the kids didnt suffocate..)

[SimmondsMills]

This was interesting from Peter in Hungary: taken from the Green Building Forum:

Biomass paper quote being responded to in Peter's post: “And further, there is a risk that the timber price is pushed so high by the competition from a growing number of biomass burners..”

We have already seen this happening here and now. A power station in the area us was converted from coal to wood burning as a short term measure waiting for a new brown coal high efficiency power station currently being built on the other side of the country. Needless to say that the wood conversion was done with an EU grant but the result of this conversion is that fire wood prices have gone up to the point that many who used to heat with wood now heat with gas as the difference is not worth the trouble. Apart from making fire wood expensive (here the poorer end of society always heat with wood, and usually with old inefficient stoves) the distances the vast quantities of wood have to be trucked is appalling. By the way the green wood is used at the area power station but any seasoned dry wood is usually trucked to Austria as they pay a premium for seasoned wood that more than covers the cost of extra transport. These events must also raise the question about the use of bio mass power stations without fully understanding / evaluating (or choosing to ignore)the real impacts of this high volume use.

[Nick Grant]

Just to be clear, the 'AECB' are saying nothing at this point. The discussion paper was commissioned as research because of various building design related concerns. The discussion paper has been peer reviewed by many experts and is the result of several months work that has changed the author's views, however it remains their views not those of the AECB.

The 'zero carbon fuel' assumption leading to less efficient buildings is as Dan says not inherent but it is a reality in the UK. The original paper had a graph from Bill Bordass taken from the Passivhaus Schools conference but we removed for the sake of brevity as it was not self explanatory. Attached here. Point we were making is that the Passivhaus school had to meet an energy rather than carbon target whilst the UK schools were designed to carbon targets, many winning sustainability awards and claiming to be low carbon. That the Reidburg school uses biomass heat confuses the story so we left it out and I'm wishing I hadn't mentioned it here!

Good to see agreement on potential biomass yield around 10% of heat demand for (Scotland) (although I'd argue this is not the same as 50% of electricity being renewable.)

It would be interesting to see if the anecdotal evidence (people working at our two local saw mills) that good timber is going for chipping is true but that isn't the crux of our argument.

As we say in the introduction, we heat our homes with wood (although our usual supplies have dried up due to demand) and would love to be proved wrong.

I'll be giving a presentation and taking part in discussion (hopefully with Alan) at the AECB conference at CAT, a site that is very much built around a biomass heat (and if they can make it work, electric) strategy. Hoping this can be a constructive discussion rather than a public lynching.

Nick

[Nick Grant]

Clearly lots of possible discussions but as one of the author's I'm keen to focus on the actual discussion paper which is not about a few people in the country with wood stoves Although the same logic also applies to us, if that was all the problem was we would not have felt the need to write this.

[Andy Hamilton]

Kate, Nick, you seem to assume that the wooded area in the UK is fixed. Hence your choice of burning or growing wood.

With the price of wood going up for use in biomass burners, more woods will be planted (especially in the north in redundant sheep farms). Note that this will sequester CO2 in that a coppice has a high degree of captured Co2 both in growing wood and the carbon rich soil beneath the trees, incorporating decaying leaves and branches.

Andy

[SimmondsMills]

It's all about a limited resource being 'fought over' by current users whilst wisely anticipating needs of new users in the future.

Andy – have any solid studies been done that suggest a possible maximum area available for reforestation in the UK, in the light that we would probably also need to plan for more land to be cultivated for food, and probably more for stay at home tourism etc? Be good to get an sense of scale on the reforestation possibilities?

It would also be interesting to see what current quantities of waste wood are being used say for the production of wood fibre board insulations abroad, and also re developments of biomass in production of next generation plastics.

i still feel that there is an unanswered case for a massive investment in demand reduction (for buildings, serious energy conservation via extensive fabric measures) before investment in promoting wood as a fuel. If there is serious money available to spend on any (cost effective for uk citizens) carbon reduction measures then (effective) demand reduction + low carbon heat supply via DH should get one of the first calls on it…and this may means more than the £10k / house being discussed at the moment for refurbishment measures.

Another question, Andy – do you support the RHI as proposed by the government? AECB consultation response refers!

[Nick Grant]

Andy H

Not assuming fixed but are assuming finite.

I'm not too worried about the exact figure but perhaps we can agree a ballpark number for % of heat or UK energy that could be met by biomass (co-generation will be main demand as we struggle to meet carbon targets given that wood is assumed to be zero C)?

Our argument is that this will be a fraction of the total, 3%, 60% I'm not too bothered. My generous guess is that it might be 10% if we plant everything we can. I don't know the figure, not my field but have not seen any figure bigger than this. Originally we thought OK so need to get UK heat demand down by factor of 10 and can then use biomass to meet heat. However then realised that (in carbon terms not renewable terms) this means that we could save more carbon by not burning that biomass.

We are not saying it is OK to burn fossil fuel, just that it is also not OK to burn biomass. If we could leave enough forest growing globally to mop up additional emissions then we could burn a bit for energy. However unless we have misunderstood something, there just isn't enough capacity – if there was we could carbon offset our way out of trouble but now I'm repeating the paper but without the benefit of editorial input.

Again we are engineers not agronomists so have not even touched on competing uses for land and solar radiation, eg food.

Nick

[Andy Hamilton]

Hi Nick, Andy, some responses to your points

Nick writes: Not assuming fixed but are assuming finite.

Yes it is finite, but there is a lot of it. I have seen figures for biomass potential but haven't got them to hand. However if you live north of the UK urban centres, as I do, you realise that most of the land in the UK is under utilised. There are thousands of square miles of under utilised land in northern England and Scotland.

Andy writes: we would probably also need to plan for more land to be cultivated for food, and probably more for stay at home tourism etc?

I agree that careful land planning is essential. For instance the Lake district could be far more productive if the open areas were turned over to managed forestry but it might encourage more people to fly off to other places for their walking holidays. This is a key issue that the government should be addressing rather than just tinkering with technology push solutions. For instance short rotation cropping of coppices (to reduce the height of the trees) underneath wind farms is a feasible way of getting two “carbon hits” from one piece of land.

I also agree that we should have a massive investment in demand reduction (but getting support is more difficult as it isn't as sexy as new techno gizmos).

However, given the scale of the problem we need an integrated approach to carbon reduction, which utilises all the resources we have. Biomass can play a useful role in such an approach, but it needs careful planning.

[Nick Grant]

Hi Andy H

We had some numbers for potential resource in original draft but thought arguing about the exact number was a distraction (we got into knots re different studies, whether to include whole EU, only heat or all energy etc). If you want to dig up some numbers you are happy with that is fine but as I say we are arguing whether burning whatever this resource is, is the best thing to do in carbon terms. If you say 12% of heat can be met by biomass I won't argue, if you say 50% I'll smile and say fine if you think so, 100% I'll want to see some evidence as it might undermine our argument.

If there is a big enough resource to make a significant impact on energy supply or carbon reduction (ignoring soil CO2 release, time lags between emission and sequestration etc etc) then this would have even more benefit if we didn't burn it.

Sure if we limited all chemical energy (ie no fossil fuel) use to what we can grow less a bit for products and sequestration, burning biomass could perhaps be sustainable but we are so far off that in terms of the numbers unless we got our decimal place wrong by about 2 places.

Even if you don't buy our plea to not burn it we would like to see some analysis as to what is best yield. Heating schools, cogeneration, CHP etc etc. And then which is most efficient crop. However we convinced ourselves that it's too good to burn.

Really want to be proved wrong on this so can feel OK about burning wood and apologise to by friends who sell biomass boilers.

Nick

[Nick Grant]

Just seen this link on Building website:

http://www.energyjustice.net/biomass

Lots on soil carbon etc which I don't claim to understand, happy to debate building related issues.

Nick

[Nick Grant]

Thanks Dave, I can sleep easy now!

The argument laid out in the article was not self evident to me and we went through various thought experiments to get to where we ended up.

Alan and I did suggest that it went out just in our names and is clearly a discussion not position paper. I'm actually very uneasy about the AECB taking a position on anything as we are such a diverse bunch but that's another discussion.

The font thing happened when someone made the Pdf and is probably a microsoft issue. I'll redo on my Mac.

Thanks

Nick

[Anonymous]

i still feel that there is an unanswered case for a massive investment in demand reduction (for buildings, serious energy conservation via extensive fabric measures) before investment in promoting wood as a fuel. If there is serious money available to spend on any (cost effective for uk citizens) carbon reduction measures then (effective) demand reduction + low carbon heat supply via DH should get one of the first calls on it…and this may means more than the £10k / house being discussed at the moment for refurbishment measures.

This is what mystifies me, why are we not focussing more of our time/energy on reducing consumption? It's not like we can't do it. Look at motor vehicles, since offering tax incentives on more efficient cars the market has responded magnificently, the 2011 BMW 3 series will have a sub 99g internal combustion engine option (3 cylinder turbodiesel), that's around 1/3 more efficient than a 5 year old 3 series.

It's futile looking at biomass as an answer, if we are offered similar incentives on domestic/workplace energy consumption then the market (in the absence of any useful government policy so far) will respond.

[Anonymous]

do you accept our proposal to consider 'tree' growing and 'tree' use as separate activities?

I can't see how you could lump them together. We've planted 8500+ trees now, how many of them have a defined use? Not even I know! I'm certainly not interested in them turning into firewood.

[Mark Siddall]

Changing the philosphical boundries somewhat and getting a little off the core topic:

For a nice little run through the fagility of biomass as an energy source have a look in “Heat” by Monbiot, pp118-119. the UK has 17 million hectares of arable land. We would need 17.8 million hectares to provide 50% of the UK's heat demand. Of course trees can survive on land that is not suited to arable use but you get the picture. It is also observed that energy crops also increase the UK's water demand.

In an uncertain future where resources are limited we need to be frugal with our energy supply where ever possible – zero carbon or not. Thanks to the authors for exposing a less well appreciated truth.

Mark

P.S. Typo ammended – oops – thanks to Dave H for spotting it!

[Anonymous]

The argument laid out in the article was not self evident to me and we went through various thought experiments to get to where we ended up.

Yes, sorry, I should have been more explicit. I have a particular set of prejudices and given those prejudices, it seems self-evident. Other people have different sets of prejudices, which is fine and good, and some people may not have any prejudices at all. So I think it's entirely right and necessary for the paper to explain everything as clearly as possible to as wide a range of readers as possible. I was just trying to summarise my own view as quickly as possible.

It should be noted that most of the UK, particularly in the west, gives poor returns on PV

Quite. This is one of the reasons I'm opposed to FITs. If we were rational about wanting to cut carbon and if we thought PV was a useful component, then we should be building PV plant in Spain or North Africa for example, and not on houses in the UK.

why are we not focussing more of our time/energy on reducing consumption?

I think the reason is that carbon, and energy in general, is too cheap. I don't think subsidising refurbishment or new build is the right way to attack it, because that leads to all sorts of unwanted side-effects, just like FITs or RHI do. The right answer is to make carbon and energy expensive enough that the obvious thing for everybody to do is to invest in not using as much energy or carbon emissions. The tricky bit is doing that without completely destroying the economy or freezing pensioners. But there are suggestions about how to do that.

Cheers, Dave

[Anonymous]

This is from the UK Tree Care forum:

http://www.tree-care.info/uktc/archive/2010/msg04157

Tahir

Your friends are confused.

To call upon the Global Forest Resources Assessment as a justification for not using biomass is
ridiculous. This assessment reflects the rate of deforestation in tropical forests – not really
relevant, other than one reason why to look at renewable fuels rather than finite sources such as
natural gas. Of course there is a limit to how much wood fuel is available in the UK for heating
purposes and increasing demand will lead to changes in the market place and woodland management.
These will be complex but assuming wood not burnt is sequestered ignores the natural decay of wood –
surely it's better to burn than to let decay in the unmanaged neglected woodland?

As ever the headlines don't do justice to a complex situation: in the green corner we have wood that
can't do no wrong and in the other corner we have nasty fossil fuels that can't do any right.
Burning wood instead of fossil fuels, if managed sensibly and not as some panacea to be used
blindfold, surely must have a role in reducing our carbon emissions?

Jon Heuch

[SimmondsMills]

Check out John Willoughby's fuel price index to see latest relative costs of different fuels.
Useful.

http://www.johnwilloughby.plus.com/dfpg1005.jpg

[KATE DE SELINCOURT]

…easier to read at 200% by the way. And of course he gives the SAP figures for CO2 including for wood – which as we have seen above, not everyone agrees with…..

[Nick Grant]

Called local sawmill at Usk today to try and order some waste slab wood for our heating. We are regular customer for timber as well as slab wood and they will try and help but have 6 month waiting list and are not taking new orders. Said that they face competition for whole trees that are being purchased for burning.

Can anyone who thinks wood is not in short supply arrange delivery at reasonable price to address near Hereford, only need about 3 tonnes and happy to saw it into logs?

Not interested in tiny pickup loads of wet wood for silly money.

Nick

[SimmondsMills]

Thanks Keith for your post below – will take a proper look through it as soon as possible

This is a relevant piece of news: 600 workers down tools to protest at Gov subsidies for burning wood http://bit.ly/9zEwEU

I would add that any fuel is only secure if it is a) available and b) affordable. How secure wood fuel is/will be will probably vary regionally and locally and follow local land ownership patterns e.g. individual landowners/the national trust should be ok (?). I personally still cannot see how the arguments that justify use of biomass as a fuel locally – can be applied to the use of biomass at a far larger scale nationally. I gather the EU are arguing that biomass fuel emissions (not set against sequestration from regrowing) should be used in calculations of GHG emissions. This implies that SAP factors would be in line for an overhaul if any decision was made to come into line with this. I will try and find out more detail on this. Meanwhile – anyone else who has inside knowledge of EU – feel free to help out….

We have invited CAT and DECC to put forward papers on the subject and hope that CAT will be able to do so.

DECC said: “We are aware of the article, having seen it on the website previously and thank you for drawing it to our attention. There are many articles published on the web or in scientific journals which hold views or provide evidence both for and against biomass and we do not individually comment on any of them. Our role, instead, is to consider the weight of evidence that these articles provide in developing government policy.”

It is also worth restating a locally specific interest I have in this debate: I live in a town, well small city (Hereford) and it is not covered by the clean air act, air quality is an issue now, and I really wouldn't support any more wood burners or biomass boilers in the city, for reasons of health. I try to stay open minded to all sides of the argument, but this aspect I can understand 'in my gut' (or rather lungs).

[Philip Newbold]

Fantastic debate folks, apart from some political posturing early on. As anyone with a basic knowledge of science knows, burning wood produces an assortment of poisonous substances, many of which led to the the passing of The Clean Air Act. As a boy, I remember walking and coughing my way through the streets of Nottingham in the fifties waving a white handkerchief in front of my parents' Austin 10 so we could get home in fog so thick you barely see the ground. In a simplistic way, I think chopping down trees just to burn them is bonkers, regardless of the pollution it causes. The South Americans are mustard at this habit with the heat generated simply providing a particularly grotesque version of global warming. The scale of what they are doing to their forests in the name of meat-eaters and palm oil consumers everywhere makes the UK biomass issue look like a small bonfire in our back yard. They don't even need Guy Fawkes to justify needlessly filling the skies with smoke

If I can just skip the argument sideways for a moment, I currently live in an old stone house with an open fire. Most winter evenings we start a fire with newspaper and sticks, a small amount of coal and then feed the fire for the rest of the evening with scrap wood from building sites. As a building designer and project manager, I regularly visit building sites and rarely leave without a bootful of timber offcuts that were destined for landfill via the skip. During the summer I can collect enough scrap timber in this way to keep my fire going all winter and sawing it up saves me going to the gym. I never buy wood. I realise that burning the wood (and the paper and coal) is poisoning the atmosphere but I justify it by getting free heat from material that would otherwise be lost to landfill although is this cheating future generations of coal deposits?

[Nick Grant]

http://markbrinkley.blogspot.com/2010/12/biomass-splits-aecb.html

[Nick Grant]

Dear Gideon

Alan and I can respond re technical aspects of the discussion paper.

1.”The authors fall into the trap that they and the inappropriate press release complains about, that of confusing biomass as an energy source, its carbon life cycles and emitter of PM10, PM2.5 and NOx and the issues and impacts they like and don’t like. “

Not sure where you think we are confused. We deliberately put aside concerns about emissions other than CO2.

2. Our argument is not about our disillusionment with Government or developer targets for energy efficiency, as you seem to imply. We are not in a huff because the whole world isn't embracing Passivhaus! If biomass really is near zero carbon then it actually makes no sense (in carbon terms) to use carbon intensive electricity to recover heat using MVHR, or to super-insulate using materials with embodied energy. Also lots of North glazing appears to reduce carbon emissions by reducing electricity use for lighting at the expense of supposedly carbon free heat. These are not hypothetical arguments but the result of rational analysis by engineers applying the zero carbon biomass assumption. These are arguments that we have been wrestling with in our daily work and are what drove us to try and clarify our thoughts.

3.”So it appears that the way the authors have argued the case, is to change the boundaries so the argument can be made, not appropriate for a supposed serious piece of work. “

One or two other people seem to be suggesting that we simply changed the system boundary currently used as a devious trick to push our agenda when in fact this was the eureka moment for us. Our journey started with this paradox; why waste energy and resources on insulation and fancy glazing if the heat source is almost zero carbon? The obvious answer is that biomass (or PV generated electricity etc) costs money and so it makes sense to not to waste it, as in the days before we worried about carbon. However the economic level of efficiency judged in terms of say simple payback is not going to deliver particularly high levels of efficiency. This would not be a problem if our energy source is genuinely low carbon and in unlimited supply.

We then thought about the fact that biomass is a limited resource so if we burn it then someone else can't and so has to use a
high carbon fuel. At this point we still assumed that biomass is net zero carbon. At some point we were discussing biodiesel made from waste oil and how far it would be reasonable to drive to get this. It seems obvious to us now that the thing to do is to put any such biofuel into the nation's diesel pool either literally or at least mathematically. This means that our own Hummer goes from being zero carbon to serious carbon emitter but the effect on the worlds's CO2 emissions is the same or slightly better if we put it into the pool (economies of scale and we don't drive 30 miles to fill our tank).

I think the car analogy is easier to grasp but the principle is the same for buildings and identical if we consider heating with biodiesel of biogas. This is what led to us questioning the currently assumed system boundary that seemed to be creating the paradox that we were struggling with.

We don't think it reasonable to draw a system boundary around a Hummer, the local biodiesel factory and as many chip shops as we need to fuel. However that is what we are doing when we claim that putting biodiesel in our car makes it zero carbon when in fact the exhaust continues to emit carbon dioxide at a similar rate to before.

The argument for biomass is slightly more involved as it is less of a liquid asset. Indeed it is not just a question of what else could we do with the trees, agricultural residue or short rotation coppice, but what else could we do with the land.

4. The CO2 figure we used was, as it says in the footnote, based on wood burnt in a boiler at 78% efficiency, ie 0.36kg CO2/kWh of wood burnt. Very happy to refine this figure if you can suggest a better one but our argument does not hinge on the precise value, which will surely vary with moisture content etc.

5. Obviously we realise that oil, gas, uranium are finite and, being concerned about climate change, should cut back on burning all fossil fuels as a matter of urgency. This is an increasingly hard challenge. We would much rather have stumbled on a solution, rather than another problem, and have everyone love us, but as Bob Lowe said: “The most dangerous problems are the ones that you think you have solved. Anything that makes you think you have solved a problem that in fact you haven’t is therefore to be avoided, at almost all costs”

Regards

Nick

[Mark Siddall]

I read the following today. It struck me the quote was pertinent to this discussion:

“”Ideally we would have the mental flexibility to find the appropriate boundary for thinking about each problem. We are rarely that flexible. We get attached to the boundaries our minds happen to be accustomed to…..
……It is a great art to remember that boundaries are of our own making, and that they can and should be reconsidered for each new discussion, problem, or purpose. It's a challenge to stay creative enough to drop the boundaries that worked for the last problem and to find the most appropriate set of boundaries for the next question. It's also a necessity, if problems are to be solved well.”

Dana Meadows, in Thinking in Systems

[Nick Grant]

Nice quote Mark.

Just received this email from Matthew Wellesley-Smith about Nitrogen Cycle implications of biomass burning which we deliberately ignored:

“You have sparked a fascinating and very timely debate. I am not able to post on the forum so i thought I'd leave it up to you whether to add this into the mix (an essay I wrote a couple of years ago for the MSc at CAT). There may be some useful references.

http://www.scribd.com/doc/46795118

Matt”

[SimmondsMills]

From a welsh farmer: http://www.i-sis.org.uk/zeroCarbonBritainOrDustBowlBritain.php

[Nick Grant]

Robert

I'd be interested to hear if you have any comments on the arguments put forward in the discussion paper.

In an early draft we were going to take your argument further and point out that if all buildings in the UK could be upgraded to the Passivhaus standard then we could meet the domestic heat demand with biomass. Still not what we think should be done even if it was possible and the pollution and other issues could be addressed.

[Nick Grant]

http://www.channel4.com/news/timber-prices-up-as-power-plants-boost-biomass-use

[Mark Siddall]

Scary….

[Nick Grant]

Link just sent by ex Director of FSC:

http://www.clickgreen.org.uk/research/trends/122080-study-finds-wood-pellet-biomass-increases-greenhouse-gases.html

[Mark Siddall]

This link offers a little more background to Nick's post (found in the comments upon the article):
http://ec.europa.eu/environment/integration/research/newsalert/pdf/234na2.pdf

I find it interesting to note that the study assumes that there is NO market conflict and still reaches these conclusions. The demand for burning biomass is increasing and driven by competition for the limited resource that is biomass prices are steadily increasing – in essence we are already witnessing the emergence of market conflict in both physical and monetary terms.

Mark

[Mark Siddall]

In interesting read: CO2 emissions from biomass combustion for bioenergy: atmospheric decay and contribution to global warming
http://onlinelibrary.wiley.com/doi/10.1111/j.1757-1707.2011.01102.x/abstract

[KATE DE SELINCOURT]

The abstract looks very interesting – if pretty technical – seems to me to be a valid perspective, ie relating climate forcing impact of burning a biomass fuel to the length of time before the emissions are taken up into plant matter again, in the harvest/grow cycle. And taking on board the realisties of actual land use systems.

Looks like a decent attempt to put a figure to the fact that CO2 is in the atmosphere temporarily after burning (or permanenetly if fuel not regrown). However as I'm not in an academic institution, no access to the paper, just the abstract, sadly.

[David Olivier]

Here is another report

ow.ly/a2P6bJd

[KATE DE SELINCOURT]

Thanks David – or nearly thanks – could not get the link to work! Could you re-post do you think?

Ta!

Kate

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