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Considering the Counterfactuals

A recently released report about the greenhouse gas implications of making power from pellets puts arrows into our industry's quiver, but also the quivers of our detractors.
By Tim Portz | August 05, 2014

On July 24th my colleague, Erin Voegele published this story which reported the publication of a scientific inquiry about the greenhouse gas implications of making power in the United Kingdom from pellet manufactured in North America. We rightly published the story with the headline “U.K. DECC model confirms GHG benefits of North American pellets”. The report is worth digging into. That said, it is a heady document that is a remarkable exhibit of the complexities of greenhouse gas accounting. 

The report’s executive summary is where I’ve spent most of my time. The first page does a nice job of setting the table about where the Department of Energy and Climate Change is headed and how it will measure its progress toward that goal. 

These items jumped out at me:

1. The Climate Change Act of 2008 mandates that the UK will reduce its GHG emissions by 80% from 1990 levels by 2050. 

2. Life Cycle Assessments will be used to calculate the carbon intensity of energy production from every pathway under consideration. To qualify for support under the Renewable Obligation the number to beat is 200kg C02e/MWh (carbon dioxide equivalent per megawatt hour).

3. For comparison’s sake electricity from natural gas is calculated at 437kg C02e/MWh and coal comes in at 1018kg C02e/MWh.

So the number to beat is 200. If the calculations for a given approach come in at 240, the juice won’t qualify for RO support which will negatively impact the financials and likely result in the project never getting off the ground.

My concern with the report comes in the pages that follow. The authors of this report, Dr. Anna L Stephenson and David J C MacKay spend a lot of time calculating the greenhouse gas benefit by considering the counterfactual. The counterfactual attempts to define what would happen with the carbon tied up in these biomass inputs if they weren’t converted to pellets and used to produce electric power. The authors assert and report in Figure 1 on page 7 of the executive summary that as counterfactuals change, the resultant carbon intensity of the biomass input changes. With some counterfactuals, the range of greenhouse gas intensity of the power made from biomass exceeds not only the 200kg CO2e/MWh metric required to qualify for RO support, but also the 437kg number of electricity made from natural gas. These are the situations opponents and critics of what we are up to as an industry have and will continue to point toward. In fact, in a chart on page 12 of the executive summary the authors identify four different scenarios where power made from biomass inputs has a greater greenhouse gas intensity than coal stoking the “biomass is dirtier than coal” debate.

My struggle is that I don’t see a counterfactual the closely aligns with what I’ve heard and witnessed first hand when it comes to forest management in the American Southeast. Loblolly pine stands in the southeast are grown intentionally, harvested intentionally and replanted intentionally to satisfy existing markets. Some markets are in decline. Some markets are emerging. These market forces are dynamic and can change year to year. I think any approach that hinges on “what may have been” or “if/then logic” run a high risk of being used to forward many different agendas. Our industry championed this report because there were instances where the assumptions and facts concluded what we all believe, that biomass derived energy offers robust greenhouse gas benefits. That said, this same report will be used to argue against the further growth of the industry, if it hasn’t already.

 

8 Responses

  1. William Strauss

    2014-08-05

    1

    Tim I agree with your thoughts. FutureMetrics was asked to comment on the DECC draft by Dr. Anna Stephenson about 6 months ago. We sent them a long and carefully crafted discussion. In that discussion we challenged the thought process on the counterfactuals. We pointed out that the real world of working tree farms in the SE and managed forests in the NE, combined with the sustainability constraints that mandate how the supply chain is run, are nothing like most of their examples. They do not seem to get it at all on roundwood-to-pellets even though that same roundwood used to go into pulp and paper mills or OSB mills that do not exist anymore. Our comments did not seem to influence their strategy to include so many unrealistic scenarios and to not recognize how the forest products industry is evolving given the changes in the demand for printed media and formed wood products. On carbon footprint, FutureMetrics has a free dashboard that is linked from our homepage that calculates kg/MWhe for the supply chain. It shows how meeting the 200 and, after 2025, the 180 kg/MWhe limits will need some supply chain optimization. www.FutureMetrics.com

  2. Tim Portz

    2014-08-07

    2

    Bill - Thanks for the note and thanks for reading. I'm writing an article about forestry in the Southeast for the October issue of Biomass Magazine that is going to dig into this very issue. I saw no counterfactuals presented that showed roundwood that FORMERLY WENT TO PULP mills identified and calculated. Thanks for continuing to carry the torch on this stuff Bill.

  3. Greener Hack

    2014-08-09

    3

    A good point, and a common mistake. But you are transferring the habits of an economics viewpoint onto a climate science framework. So far as a tree growing now is concerned, what happened to the OSB industry years ago is not relevant: it will either continue to grow (the no-harvest counterfactual) or it will be cut down for fuel (the bioenergy scenario). From the viewpoint of the atmosphere (where the CO2 climate forcing happens), these are the only two things that matter. The economics viewpoint is valid for looking at wider issues, and the response of the whole market supply and commercial interaction issues. To do that properly requires the LULUCF accounting framework or something similar. This is also a good thing to do. But mixing up the two approaches as you have done is (sorry) incoherent and will lead to more heat than light.

  4. Greener Hack

    2014-08-09

    4

    The separation of viewpoints is useful. The economics tells you which scenarios are likely to occur, given different levels of subsidy for wood pellets. The carbon accounting models tell you the consequences of each of those scenarios. The carbon accounting models also flag up particularly dire scenarios which it is well worth putting a lot of effort into avoiding.

  5. William Strauss

    2014-08-09

    5

    In fact, the climate science framework fits into the same argument. The SE plantations and northern managed forests have been in rotation for generations. They are crops that take 15 or more years from start to harvest. The carbon cycle is complete as long as the harvest rate does not exceed the growth rate. If a plot grows 1000 tons per day of new growth and the harvest is 1000 tons per day or less for use as fuel, then any carbon released from the combustion of that fuel is absorbed that same day by the new growth. Without a use for that slow motion crop, as those stands mature, their carbon intake rate declines and at some age the forest reaches an equilibrium at which natural mortality stops net carbon intake. Most forests in the US are privately owned. Most forest landowners grow trees as a feedstock for the forest products industry. What happens when there is no demand for their crop? Land use change (conversion to agriculture or housing development) or decay. Keeping the working forests working and using some of those forest products for fuel offsets fossil fuels and adds no new net carbon to the biosphere. There is no net forcing from wood combustion as long as the sustainability constraint of harvest rate < growth rate is kept. Renewable energy has to renew and energy from sustainably managed forests is 100% renewable. Sure there are lots of counterfactuls but by and large most do not reflect the reality of how working forests are managed. Yes if we cut all the trees down it would be very bad for net atmospheric carbon. Most forest landowners nurture there assets, and all pellets sent to the EU and UK must be sourced from certified sustainable forests. We cannot shrink the forests. But within that constraint, we can continue to grow and harvest trees as has been done for many generations and use them responsibly as a source of energy that does not add new carbon to the atmosphere.

  6. stewart boyle

    2014-08-11

    6

    The problem with this debate - which the BEAC publication has not really helped so much - is that the fine grain of detail will be ignored by most Green activists and Board Industry co's like Norboard who are biased against most bioenergy use. There is enough in the scenarios of BEAC to show that biopower is either bad, or OK, or pretty good. Take your option and send out the appropriate press release to your friendly journalist. The just published Forest Research and JRC reports from the EC on biomass sustainability contain a huge amount of positive data and conclusions over bioenergy use, but opponents (like GreenerHack) will still point to the less beneficial scenarios using extreme scenarios to oppose imported US pellets to biopower in Europe option. By pushing for 'perfection now' in bioenergy, green activists hand an own goal to those totally opposed to all renewables or pushing the nuclear big subsidies line. In truth we are going to need a host of renewable technologies, including transition ones for biofuels and biopower, to get us anywhere near the big carbon cuts now needed. As a former green activist it troubles me to see selective use of science used to kill off critical bioenergy investment and technologies that would get us to the even better technologies.

  7. Greener Hack

    2014-08-13

    7

    Perhaps I can help by indicating one of the BEAC scenarios that Strauss, with his local knowledge, can give us a reality check on. If a forest owner has no immediate market for a pulpwood stand at the year at which it would normally be harvested, would he leave it growing for another year or two? Conversely, if the price was really good, would he cut it down a year or two early ? It is this behavior at the margin which is where we will find the more realistic scenarios. Scenario 14 is a 25 to 20 year comparison and is either as bad as gas or as bad as coal depending on whether you take a 100 or 40 year viewpoint. I wonder what it would be for a 21 to 19 year comparison?

  8. Greener Hack

    2014-08-13

    8

    [Perhaps you will also allow me to point out that it is bad accounting, not biomass, that I am opposed to. I care very much that billions of euros earmarked for climate mitigation activities are being spent where they not only don't do much good, but where they actively subsidize increased CO2 levels.] What we need in the North American forests is carbon accounting certificates that actually do what they need to do.

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