Dal/AC’s revamped biomass plant provides heat and power for the Truro campus and generates over a million dollars annually from exporting electricity. But is it truly carbon neutral and will it stay that way?
UPDATE: Comment from Rochelle Owen Executive Director, Office of Sustainability at Dalhousie University
There has been recent publicity around the Dalhousie University/AC’s revamped Biomass Energy Plant, Dal touting it as “a (Bio) Massive Achievement” and “a North American First” (AC: Agricultural Campus)
Dal’s Agricultural Campus has its sights set on being completely carbon neutral — a goal highlighted at the opening of the new Biomass Energy Plant, which celebrated its grand opening Tuesday morning (Nov. 20).
The renewed [30 year old] plant and district energy system, a $26.5-million project that began operation this summer, burns biomass fuel in a thermal oil heater. This heat moves a new 1 MW turbine to create electricity — an organic rankine cycle (ORC) system that’s the first of its kind on a North American university campus. It’s technology that places Dal on the leading edge of sustainable technology and renewable energy practices.
View A (BIO)MASSIVE ACHIEVEMENT: NEW AG CAMPUS ENERGY PLANT A NORTH AMERICAN FIRST
by Ryan McNutt in Dal News (Nov 21, 2018)
The Grand Opening on Nov 20 was attended by Nova Scotia Minister of Lands and Forestry Iain Rankin.
Guests at Tuesday’s launch were able to take a tour through the new facility, led by Dal Project Manager Peter Cherry from Facilities Management along with Kevin Craig (chief engineer) andMichael Conte, FVB owner’s engineer. The tour showcased the two large fuel storage bays, where the biomass fuel is stored. Over 85 per cent per cent of it sawmill residue from a local mill and local yard and clean wood waste, while the remainder is two smaller amounts of research fuels. (The plant is expected to need less than 20,000 tonnes of bioenergy to run annually.)
An article in the Truro News provides more details; view PHOTO GALLERY: Dal AC opens revamped Biomass Energy Plant in Bible Hill by Fram Dinshaw, Nov 20, 2018
Dal/AC have gone after a state of the art facility on the technical front:
The restored plant burns mostly sawmill residue using hot gas to warm up thermal oil, feeding heat energy into the plant’s new organic Rankine cycle (ORC) system that drives the turbine. Dalhousie is the first university in North America to use the technology in burning wood fuel.
…The plant’s new hot water distribution system is 30 per cent more energy efficient than the former steam system. Sixteen energy transfer stations were converted from steam to hot water and another 2.6 km of hot water pipes were installed.
To further combat air pollution, the plant has installed an electrostatic precipitator to remove harmful gas particles using electrically-charged plates.
Wood ash generated by the renewed plant will amount to about 400 tonnes per year and is used as farm fertilizer. –Truro News
On the financing end:
As well as supplying energy to the Dal AC campus, the plant sells electricity to the Nova Scotia Power grid under the province’s Community Feed-in Tariff (COMFIT) program at a rate of 17.5 cents per kilowatt-hour. The restored plant began producing electricity in June and can meet up to 75 per cent of Dal AC’s energy needs. –Truro News
Planning for the replacement system began when the provincial government was running the Nova Scotia Community Feed-in Tariff (COMFIT) program. COMFIT was designed to encourage community-based, local renewable energy projects by guaranteeing a rate per kilowatt-hour for the energy the project feeds into the province’s distribution electrical grid. The AC Biomass project received approval in 2014…“Selling the extra power is expected to generate $1.36 million annually…” – Canadian Biomass
About the fuels, the Truro News article provides this info:
The university is already researching more expensive fuels that could provide a sustainable fuel source in future – one research project will look into the feasibility of growing and burning willow, which is fast growing, absorbs water and grows well in marginal lands not suitable for food production crops.
The second study will look at using the wood from selective harvests and silviculture.
An earlier article about the plant in Canadian Biomass (May 27, 2018) cites “appropriately harvested stem wood” as one of the potential feedstocks and that “This project will support the local economy by providing a dependable demand (approximately 20,000 tonnes per year) for local biomass producers.”
From a 2012 Dal document“: “Last year the Dalhousie Agricultural Campus Central Heating Plant produced over 75 per cent of its total stream output by burning 8,000 tons of wood chips…”
The old system was used only for heating, not for electricity. The new system has been described as producing electricity with waste heat used for heating the campus
“This small 1 megawatt biomass co-generation plant project focuses on energy efficiency and securing local sustainable supply,” explains Rochelle Owen, director of the office of sustainability for Dalhousie. “Waste heat from electricity production is used for heating the campus. The plant design will allow flexibility for future products like willow.” – Dal News, April 21, 2016
I hope I can be forgiven for expressing some concern that when push comes to shove and there are not enough processing wastes available to run the facility, “low value wood” will be used. I note that the older system took in 8000 tons of wood chips, the new one takes in “approximately 20,000 tonnes per year”, and that the new plant will export electricity (presumably purchased as renewable energy and subsidized accordingly). Hence I am guessing that there will be some financial and possibly contractual pressure to maintain electrical output and substitute “low value wood” or “waste wood” (but still primary biomass) for wood processing wastes (secondary biomass) as the main feedstock when the latter are in short supply. That would likely make the operation a net producers of GHGs compared to alternatives over meaningful time frames, as is likely* the case for the Port Hawkesbury biomass plant.
*I say “likely” in regard to the Port Hawkesbury biomass plant because there is no public accounting of the feedstocks, except that in 2016, then NSDNR Associate Deputy Director Deputy Minister Alan Eddy commented that NSP has “an obligation to its ratepayers to get wood fibre as cheaply as possible” and “the cheapest way is to clear land, not selectively harvest to improve the lot for the future.” – The Coast, Apr 21, 2016 ; view also NSP, PHP, NSDNR and FSC appear to be complicit in burning primary biomass from Loon Lake area, increasing GHG emissions, and calling practices “sustainable”, Post on NSFN Mar 17, 2018. (I have written both NSP and PHP asking for information on feedstocks, never got any reply or even acknowledgement.)
On top of the feedstock issue , the use of biomass to produce electricity (versus just heat) further reduces the likelihood that a particular bioenergy configuration will be carbon neutral (as always, within meaningful time-frames) because of the relative inefficiency in conversion of heat to electricity.
Hence my comment on the Dal News Item (submitted Nov 21, approval still pending):
Good for Dal/AC. Because of the controversies surrounding bioenergy and use of forest biomass in particular, I hope you will publish an annual report with an accounting of feedstocks and actual savings (or net increases) in GHG emissions compared to other operations on campus, i.e. the counterfactual scenario should be the energy sources that are used elsewhere on campus to generate heat and that would be used if this facility were not available. I am guessing those are some combination of electricity (generated from some mix of coal, wind etc), natural gas and fuel oil.
The science and process of GHG accounting is complex and controversial** but Dal has many experts in such matters, e.g. in Life Cycle Assessment, climate change science, public policy etc. so if any group in Nova Scotia has the capacity to address this issue comprehensively, objectively and transparently, it is Dalhousie University.
If Dal does take a comprehensive, transparent, and critical approach to assessing the GHG emissions issue (and let the chips fall where they may, so to speak), it could be a good lesson in critical thinking and transparency for all of us, and timely given the recent dire warnings about climate change from the IPCC, and their reservations about forest bioenergy.*** Indeed it would be another “(Bio) Massive Achievement” and quite possibly also “a North American First”.
** Re “controversies surrounding bioenergy”, see, e.g.
– Bioenergy the turning tide: Biomass emissions are not carbon neutral – we need to change how we account for them
by Eddy Issacs, July 12, 2018. University of Calgary School of Public Policy blog
– Environmental Research Letters 2018: Focus on The Role of Forests and Soils in Meeting Climate Change Mitigation Goals
Two papers in the first issue on this topic are very pertinent to biofuels and GHGs:
—Does replacing coal with wood lower CO2 emissions? Dynamic lifecycle analysis of wood bioenergy
John D Sterman et al. 2018 Environmental Research Letters, Volume 13, Number 1 “Bioenergy is booming as nations seek to cut their greenhouse gas emissions. The European Union declared biofuels to be carbon-neutral, triggering a surge in wood use. But do biofuels actually reduce emissions?…Assuming biofuels are carbon neutral may worsen irreversible impacts of climate change before benefits accrue. Instead, explicit dynamic models should be used to assess the climate impacts of biofuels.”
–Not carbon neutral: Assessing the net emissions impact of residues burned for bioenergy
Mary S Booth 2018. Environmental Research Letters Volume 13, Number 1. “…for ‘low carbon’ assumptions about residues to be reasonable, two conditions must be met: biomass must genuinely be material left over from some other process; and cumulative net emissions, the additional CO2 emitted by burning biomass compared to its alternative fate, must be low or negligible in a timeframe meaningful for climate mitigation.”
– Forest Biomass Energy Policy in the Maritime Provinces: Accounting for Science
East Coast Environmental Law Report by Jamie Simpson, Dec. 2015. “We evaluate whether government policy on forest biomass in the Maritimes is keeping pace with science. Is the harvest of forest biomass sustainable from a biodiversity perspective and does the burning of forest biomass reduce overall carbon emissions? If not, then should governments continue to offer incentives to make forest biomass energy economically feasible?”
*** The IPCC report is pretty clear that to reduce CO2 emissions over a meaningful timeframe, forest bioenergy systems need to be coupled to Carbon Capture and Storage. Forest bioenergy systems that do not provide net reductions in GHGs compared to alternative fossil fuels within 25 years are contributing to global warming and perhaps more ominously, the danger of run-away warming (e.g. associated with release of carbon dioxide and methane from melting permafrost).
SOME RELATED POSTS ON NSFN
Nov 22, p.m. I received a message from Rochelle Owen, Executive Director, Office of Sustainability at Dalhousie University responding to the comment I made (cited above) on the Dal site about the Dal news Item.
“Hi David, I saw your note on Dal News. Attached is our fact sheet about the system. Under the next steps section, we have research for next summer that would be inline with your comment. Be happy to receive your feedback on methodological considerations. Rochelle”.
I have asked if the fact sheet is posted online, so I could link to it. In the meantime, following are a few extracts (italics are mine):
Fuel supply. The University created a biomass value statement that outlines standards for biomass supply. Biomass supply must meet the conditions of COMFIT rules. These statement and standards provide direction on topics such as fuel type, trucking distance (distance of fuel 175 km or less), and land uses (Appendix A – COMFIT Directive.). The University each year will submit a COMFIT report that outlines where fuel comes from and calculates contributions to silviculture programs though The Registry of Buyers. The majority of biomass (over 85%) is sawmill residue [bark and shavings] from a local mill and smaller amounts of local yard and clean wood waste [residue from the making of lobster traps] and two smaller amounts of research fuels (chips from selective forest harvests for siliviculture through local forestry cooperatives and an agreement for willow). The bioenergy requirements for the plant is projected to be less than 20,000 tonnes per year.
• In the summer, process heat is used to heat domestic hot water. There is more available heat for use during this period. Our plans are to identify matching funding for a study and solution to capture and utilize this available heat in the summer. This would be the second stage of innovation.
• We will be researching the full-life cycle carbon comparison of the biomass used in this system versus alternatives which would have been oil or compressed natural gas.
• Carbon Neutrality. The campus-based biomass co-generation plant is a positive strategy compared to the alternatives; as a strategy it is not completely carbon neutral. It is part of a broader University plan that pursues many strategies to meet carbon targets including energy efficiency, solar and other renewable energies, and capturing waste heat through process like co-generation. In 2018, the University will be releasing Version 2. of the Climate Change plan that will include the Agricultural campus (version 1 was released in 2010).
I am pleased to see that Dal “will be researching the full-life cycle carbon comparison of the biomass used in this system versus alternatives which would have been oil or compressed natural gas”, which is essentially what I was suggesting. ‘Good as well to see some clarity on carbon neutrality of the biomass co-generation plant (“as a strategy it is not completely carbon neutral”).
I hope Dal will provide more info about the carbon neutrality aspect in their future PR and that their initiatives in this regard will be noted by other biomass energy producers and by provincial politicians and bureaucrats dealing with forest biomass issues. I hope also that some Nova Scotia academics will delve further into bioenergy/GHG issues for the province as a whole. Perhaps they already are.
In the process of looking for the Fact Sheet (cited by Rochelle Owen) on www.dal.ca, I found this document which gives some background on the COMFIT program (the program was ended in 2015):
DALHOUSIE UNIVERSITY GENERATING RENEWABLE ENERGY THROUGH THE COMFIT PROGRAM: AN EXPLORATORY STUDY Matthew Andrews et al, Client: Wayne Groszko SUST/ENVS 3502 April 13, 2012. “Our team undertook an exploratory research project to explain how Dalhousie University could produce renewable electricity using wind power within the context of Nova Scotia’s Community-based Feed in Tariff (COMFIT) program. The COMFIT program allows communities to create renewable electricity that connects to the provincial electricity grid. In return, Nova Scotia Power Inc. (NSPI) pays the communities a set, premium rate per kilowatt hour (kWh) for their energy.