Environmental impacts of wood heat – what we can do- is there need for environmental regulation to ensure that carcinogens are not going straight into the lungs of our children?
For example, external wood furnaces (e.g. “Wood Doctors”) with short exhaust pipes may blanket immediately surrounding areas in smoke each winter. Perhaps regulations on the height of the exhaust pipe (i.e. flue / chimney) are required?
- National Post – Dec 22, 2015 – Montreal residents will have to register their fireplaces and wood-burning stoves — or face a $500 fine
- “Starting in 2018, wood-burning appliances will be banned unless they meet the rigorous new emission standards of 2.5 grams of fine particles or less per hour. The bylaw is among the strictest in North America, said Réal Ménard, the city’s executive committee responsible for the environment. Presently, transforming a stove or fireplace with inserts so that it is in compliance with the coming regulations costs between $2,000 and $8,000.”
CBC via Citizens Alliance News – Chris Ortenburger – Jan 5, 2016 – Nova Scotia biomass burning regulations questioned in new report
Biomass — it’s a complicated fuel source.
And maybe not as green as we would like to think. That’s the well-researched conclusion of a new report on biomass in the Maritimes.
A CBC article with a link to the report is here:
And the author tweeted:
I report I wrote on burning trees for electricity (summary: bad idea!) https://t.co/6SL5HLRxpe
— Jamie Simpson (@Jamie_forester) January 3, 2016
The report was written by Jamie Simpson, a forester, lawyer and former executive director of East Coast Environmental Law. (If the name is familiar, he has been on the Island as the guest speaker at the ECO-PEI annual general meeting last year, led a workshop on environmental rights the year before, and spoke at a forum on cosmetic pesticide municipal bylaws a couple of months before that.)
I haven’t read more than the conclusions yet, and Section 5 which is about P.E.I., but from what I have read of his about this issue before in the small but powerful Atlantic Forestry publication (which is printed below with his permission), it’s not the best basket to put a lot of a province’s energy planning eggs in, especially for electricity generation.
It is in the P.E.I. Renewable Energy Act (1988) to try to get to 15% of electricity from renewable sources (including biomass) by 2010. It appears that fortunately the biomass in this equation hasn’t been pursued. My understanding is that biomass is used for heating some government institutional buildings, primarily (and of course wood used for heating residential private homes). It’s not as “carbon neutral” as we would hope it would be, and the current amount and certainly any expansion should be done with extreme care in our debilitated woods. (And we keep missing the forest for the trees by not working on maximizing energy efficiency first.)
Here is the short, older article with some good background on biomass in general:
Biomass Energy: Does burning our forests for electricity really reduce carbon emissions?
by Jamie Simpson
Originally published in Atlantic Forestry Review,(DvL Publishing, Bridgewater, N.S.) May 2015
shared with permission of the author
“Burn a tree, grow a tree. It’s simple, Jamie!”
So said an exasperated Natural Resources minister to me once. At a conceptual level, his argument sounded sensible. While the burning of fossil fuels results in a one-way flow of carbon into the atmosphere, the carbon released into the atmosphere by burning one tree should be offset by carbon taken up when a new tree grows and takes its place – or so it might seem. Based on this simplistic premise, governments around the world – including Nova Scotia – have introduced policies to encourage biomass energy development, buoyed by the hope of reducing carbon emissions while creating demand for low-value forest products.
It’s important to note that nowhere in the world is forest biomass electricity development driven by the energy market; the feasibility of these projects so far depends on some manner of government policy support. When representatives for Nova Scotia Power Inc. (NSPI) were asked whether the company would pursue the Point Tupper biomass project if not for the province’s renewable energy requirements, the answer was a definite “no.” Why not? Cost and risk, of course. The government’s regulated targets for increased renewables provided an opportunity for NSPI to shift that extra cost and risk to Nova Scotian rate-payers.
Given that forest biomass electricity hinges on government support, it’s worth asking what we are getting in return for assuming these costs and risks – not to mention the negative effects on our forests and our value-added hardwood industries. If the government’s intention is to reduce our carbon emissions, then we have a right to know whether Point Tupper actually delivers this benefit.
As it turns out, the assumption that forest biomass electricity reduces carbon emissions is rather brittle. The dynamics of forest regeneration, carbon emissions, and biomass energy are not as simple as the “burn a tree, grow a tree” argument. Although this is counter-intuitive, burning trees to make electricity can put more carbon into the atmosphere than burning coal, at least for the next few decades. Burning trees to heat buildings, however, may reduce carbon emissions. Yes, it’s complicated.
There are three key issues at play here. The first thing to consider is the time it takes a forest to soak up carbon from the atmosphere after biomass is harvested and burned, and whether the forest is even able to soak up an equivalent amount of carbon. The lag time between biomass burning and carbon take-up is important, because we need carbon reduction now, not decades down the road. Scientists tell us that if we can’t get a handle on carbon emissions in the near term, future reductions may not provide much benefit.
Furthermore, because biomass is often produced by clearcutting stands that would otherwise be uneconomical to harvest, the development of this sector may decrease the average age of our forests. Because older forests contain far more carbon than younger forests, biomass harvesting can result in a one-way flow of carbon from our forests to the atmosphere.
A Princeton University scientist named Timothy Searchinger, along with 12 of his colleagues, wrote about this way back in 2009, in an article in the journal Science, titled “Fixing a Critical Climate Accounting Error.” They made the point that land used for biomass fuels may, over the long term, store less carbon per hectare than it did before biomass harvesting. The upshot is that burning forest biomass results in immediate carbon emissions which may or may not be taken up by the forest decades in the future.
The second part of the biomass energy equation is how efficiently trees are converted to energy. Burning wood to produce heat, for example, can be 80 percent efficient or even a bit higher. Burning wood to generate electricity, on the other hand, is far less efficient, in the neighborhood of 21.5 percent. Some biomass electricity facilities can put waste heat to use, thereby increasing their efficiency.
By supplying some thermal energy to Hawkesbury Paper, its pulp mill neighbor, Point Tupper, when operating under its best case scenario, can achieve 36 percent efficiency. In other words, of the 50 truckloads of wood delivered to that plant daily, at least 32 truckloads are wasted, quite literally, up the smokestack. (Of course, the carbon from all 50 truckloads goes into the atmosphere, regardless of how much energy is produced.)
Finally, the third issue at play is the carbon intensity of the fuel being replaced by biomass. For example, choosing between biomass and coal is far different from choosing among biomass, coal, and natural gas. Electricity from natural gas is far cleaner than coal, and coal is cleaner than wood, on the basis of carbon released at time of burning per unit of energy produced.
A team of forest biomass energy researchers in Massachusetts found that under a best-case scenario (low-impact forest harvesting; use of biomass for heating rather than electricity; and replacing the dirtiest of the fossil fuels), forest biomass can become carbon neutral in as little as 10 to 20 years. However, under a worst-case scenario (clearcutting; burning wood for electricity; and replacing the least dirty of fossil fuels), the researchers found that forest biomass would not become carbon neutral within a century.
To put these results in perspective, the researchers offered a snapshot of estimated emission levels in 2050 (assuming that the forest actually does eventually sequester all of the carbon released). Replacing a coal-fired power plant with a biomass electricity plant would result in a three percent net increase in emissions by 2050, and replacing a natural gas power plant with biomass would result in a 110 percent net increase in emissions. Replacing an oil-fired heating system with a biomass heating system, on the other hand, could result in a 25 percent net reduction in emissions by 2050. These are rough numbers, of course, but so far no one has refuted the researchers’ methods.
Researchers in Ontario, studying the Great Lakes-St. Lawrence forest region, ended up with similar results. Jon McKechnie and his fellow researchers found that replacing coal-fired electricity with forest biomass electricity would increase carbon emissions for some 16 to 35 years. These researchers also investigated converting trees to ethanol to be used as a substitute for gasoline, and they found that this would increase carbon emissions for more than a century.
Researchers in Norway have taken the biomass energy question to another level. Bjart Holtsmark noted that previous studies had failed to account for the impact of repeated biomass harvests. He found that when multiple biomass harvests on the same piece of land are factored in (based on the forest reaching economic maturity), net carbon emissions from forest biomass electricity remain higher than coal-fired electricity for some 250 years.
There is also research pointing to reduced productivity in certain soils following some types of harvesting. Once the productive capacity of soil is compromised, the forest loses some of its capacity to sequester carbon. This appears to be the case in Nova Scotia, according to research commissioned by the provincial Department of Natural Resources. Unfortunately, DNR has yet to release the full results of this study.
So far, most governments have clung to their policies that make biomass electricity projects economically viable. Under Nova Scotia’s Renewable Energy Standard, biomass electricity still qualifies as renewable, regardless of its actual impact on carbon emissions. But there are signs of a shift. The European Union has recommended that existing biomass energy facilities should emit 35 percent less greenhouse gases than the fossil fuels they replace, and that new facilities release 60 percent less by 2018. The value of these non-binding recommendations is questionable, however, given that the EU’s Renewable Energy Directive and its Biomass Action Plan continue to drive development in this sector.
Massachusetts, on the other hand, has actually adjusted its energy policy based on our new understanding of carbon accounting in relation to biomass. The state introduced a minimum efficiency requirement of 50 percent for biomass energy projects, a minimum of 60 percent efficiency for projects to receive full renewable energy subsidies, and the further requirement that a proposed biomass facility will reduce carbon emissions by 50 percent over its first 20 years of operation relative to a new natural gas facility. If such requirements were in place in Nova Scotia, the Point Tupper plant would not qualify for the special treatment which enabled NSPI to build it and have electricity consumers pick up the tab.
What should we be doing differently? Nova Scotia’s Department of Energy needs to take a hard look at the science of forest biomass energy and carbon emissions, and adjust its Renewable Energy Standard accordingly. If Point Tupper cannot meet a 60 percent minimum efficiency requirement, perhaps it should no longer qualify as a source of renewable energy. Small-scale biomass heating projects, on the other hand, should be further explored for their potential to reduce carbon emissions while reducing our reliance on fuel oil and electric heat.
Furthermore, Nova Scotia’s Department of Natural Resources should introduce forest harvesting regulations to ensure that carbon storage in Nova Scotia’s forests is increasing over time, rather than decreasing. This would also help avoid the detrimental effects on biodiversity which result from clearcutting for biomass fuel.
Given the increasingly apparent negative impacts of forest biomass electricity, it’s time for Nova Scotia to reassess the costs and benefits. We can continue to fool ourselves with simplistic and false assumptions, or we can look at the scientific evidence and start making the difficult but necessary decisions.