Results for category "LCA"

4 Articles

Measuring the Success of British Columbia’s Renewable and Low Carbon Fuel Regulation

British Columbia’s (B.C.) Greenhouse Gas Reduction (GHGR) Targets Act (GHGRTA) contains ambitious goals of reducing province-wide greenhouse gas (GHG) emissions by 33% in 2020 and 80% in 2050 (relative to 2007). With ~38% of B.C.’s GHG emissions stemming from transportation (in 2012), it is clear that B.C.’s GHG emissions reduction goals can only be realized with an effective transport fuel policy. Enacted in December 2009, the GHGR Renewable and Low Carbon Fuel Requirement (RLCFR) Act and Regulation have achieved significant GHG emissions reductions accredited to its enforcement with 904,900 t CO2eq emissions reduction in 2012. At face-value, this is a great success. However, there are several accounting issues that suggest these GHG emissions reductions are inaccurate.
In a recent study published in Biofuels, we show that the RLCFR legislation has not been nearly as effective as proclaimed by the B.C. government. Nevertheless, this transport fuel regulation is essential if B.C. wants to achieve its future GHG emissions reduction targets.
If you’d like more details, please feel free to contact us. Otherwise, here’s a brief overview of the paper…

An Intro to BC’s fuel regulation

With overwhelming consensus (Cook et al., 2013), it’s become clear that human-induced climate change is a serious issue and this has led to a number of local jurisdictions stepping up their climate action plan with bold targets written into legislation, where B.C. is poised to be at the forefront. Taking inspiration from California’s Greenhouse Solutions Act (approved September 2005) the Liberal government of B.C. first expressed their ambitious GHG emissions reduction targets during the reading of the provincial Throne Speech in February 2007 with now legislated targets of reducing GHG emissions by 33% in 2020 and by 80% in 2050—relative to GHG emissions in 2007 (64.3 Mega tonnes (Mt) CO2eq) (Sodero, 2011). One act/regulation that has gained particular notice is the GHG emissions reduction Renewable Low Carbon Fuel Requirements (RLCFR) Act/Regulation of B.C. (B.C. Government, 2014), because it has been noted and given media attention as being B.C.’s most effective climate legislation to date in terms of reducing GHG emissions (Thomson, 2015; Wolinetz & Axsen, 2014).
Enacted in December of 2009, the RLCFR Regulation requires two main conditions of large-scale (greater than 75 million m3 per year) transportation fuel suppliers of B.C. Firstly, these fuel suppliers are required to blend their fossil gasoline and diesel fuels with at least 5% and 4% of renewable fuels, respectively (B.C. Government, 2014). Secondly, these fuel suppliers must ensure that the life cycle carbon intensity (CI) of their fuels is below the CI limit prescribed during a given year, where this CI limit is set to be reduced by 10% from 2011 to 2020 (B.C. Government, 2014).
According to B.C. government accounts the RLCFR has been a success thus far, where in its first three years, GHG emission reductions attributed to the RLCFR have increased: 558.7 Kilo (K) tonnes (t) CO2eq in 2010 to 904.9 Kt CO2eq in 2012 (B.C. Government, 2012). In fact, a recent report has stated that the RLCFR is currently B.C.’s most important piece of climate legislation where it has contributed to 25% of B.C.’s GHG emissions reductions in 2012, relative to the 2007 baseline year (Wolinetz & Axsen, 2014). With this early success, it is important to ask how this reduction in GHG emissions is being calculated and whether there are any important life cycle accounting measures being left out of the equations.

What the study did

The study looked into the details of the RLCFR of B.C. to firstly understand how past GHG emissions reductions that are being reported and accredited to the RLCFR are being calculated. Secondly, this study highlighted two key CI accounting items that the RLCFR neglects to consider: incorporating indirect land use change (iLUC) and developing fossil fuel CIs that are representative of the fossil fuel mix of a given compliance period.

Now let’s take a closer look at iLUC.

Why iLUC is important

The inclusion of iLUC is important because GHG emissions due to iLUC can lead to a significant increase in CI (Broch, Hoekman, & Unnasch, 2013). For instance, Ahlgren & Di Lucia (2014) undertook a review of iLUC modelling results and found iLUC factors for corn and wheat ethanol to range from 7 to 104 g CO2eq/MJ and -80 to 155 g CO2eq/MJ, respectively. For canola, soy and palm-based biodiesel, iLUC factors ranged from 2 to 220 g CO2eq/MJ, 2 to 270 g CO2eq/MJ and 3 to 114 g CO2eq/MJ, respectively (Ahlgren & Di Lucia, 2014). These iLUC factors are substantial given that the most recently approved CIs (iLUC not included) reported by the B.C. Government for ethanol, biodiesel and hydrogenated derived renewable diesel (HDRD) ranged from -4.23 to 70.36 g CO2eq/MJ, -0.05 to 38.32 g CO2eq/MJ, and 18.16 to 63.66 g CO2eq/MJ, respectively. The inclusion of iLUC factors for B.C.’s dedicated crop‐based ethanol and biodiesel fuel sources would dramatically change the perceived benefits of a renewable fuel that is derived from cropland.

What we found in the accounts as reported

In terms of total GHG savings, the reported GHG savings are 12% higher than those calculated in this study using the regulation’s equation. As illustrated in figure 1, the main disparity stems from GHG savings due to the use of biodiesel and HDRD fuels. In all cases, except for propane, the reported savings tend to be higher than the values we calculated using the regulation’s specified equation.
Figure 1: Greenhouse gas savings (kilotonnes [Kt] CO2eq) in the year 2012 attributed to the RLCFR Regulation for each alternative fuel type. Values are presented as those reported in the government accounts and as a result of own calculations. Percentage values represent the C/¡ % difference of calculated results relative to reported values. HDRD = hydrogenated derived renewable diesel; CNG = compressed natural gas; LNG = liquefied natural gas.

Figure 1: Greenhouse gas savings (kilotonnes [Kt] CO2eq) in the year 2012 attributed to the RLCFR Regulation for each alternative
fuel type. Values are presented as those reported in the government accounts and as a result of own calculations. Percentage
values represent the C/¡ % difference of calculated results relative to reported values. HDRD = hydrogenated derived renewable
diesel; CNG = compressed natural gas; LNG = liquefied natural gas.

How reductions change when iLUC is included

GHG savings are greatly reduced when the average iLUC factors are included. In some cases, from this GHG perspective it would have made more sense to use conventional petroleum-based gasoline and diesel in place of these GHG intense crop derived ethanol and HDRD supplies consumed in B.C. These significant fuel-specific reductions in GHG savings, in turn, equate to significant reductions in total 2012 GHG saving, as is depicted in figure 2.
Figure 2: Total greenhouse gas emissions savings in the year 2012 that are attributed to the RLCFR Regulation when iLUC factors are included. Total values are calculated using own calculations. Calculated and reported savings with no iLUC factors are also included (horizontal broken lines) for comparison. SD = standard deviation of iLUC factors. ‘#’ yr AP = amortization period (years) to divide iLUC related GHG emissions across; K = kilo ('000). Negative values indicate no savings or a net burden.

Figure 2: Total greenhouse gas emissions savings in the year 2012 that are attributed to the RLCFR Regulation when iLUC
factors are included. Total values are calculated using own calculations. Calculated and reported savings with no iLUC factors are
also included (horizontal broken lines) for comparison. SD = standard deviation of iLUC factors. ‘#’ yr AP = amortization period (years) to divide iLUC related GHG emissions across; K = kilo (‘000). Negative values indicate no savings or a net burden.

Figure 2 displays the range of total 2012 RLCFR-related GHG savings when iLUC is factored into the calculations and it clearly shows the importance of including iLUC where even the application of median iLUC factors can lead to greater than 50% reductions (see triangle markers in figure 2) in total GHG savings. As the amortization period increases, the range of GHG savings converges because the iLUC factors decrease. When a 30 year amortization period and the median iLUC factors are applied, total 2012 GHG savings are reduced from the reported 904.9 Kt CO2eq, to 505.4 Kt CO2eq—a significant 44% decrease.

Some important points of discussion

Another important caveat that is lost in the RLCFR reported total savings lies with electric mobility. The majority of GHG savings attributed to electric mobility stems from B.C.’s lower mainland (greater Vancouver area) sky-train and trolleybus system in which most of this transport network existed well before the RLCFR regulation was enforced in 2010. In other words, the RLCFR cannot claim any sort of additionality or credit for implementing the vast majority and if not all of this low-carbon mode of electric public transportation.
Another concern is that there is no public RLCFR documentation that provides an explanation as to why iLUC is not accounted for. Uncertainty should not be an argument for systematically excluding iLUC from the life cycle CI of a biofuel (Muñoz et al., 2015). Even with the level of uncertainty in iLUC factors to date, including iLUC gives us an indication of an extremely relevant hotspot that should not be overlooked. The inclusion of iLUC makes the CIs of biofuels more accurate, not less. In other words, it is better to be ‘approximately right than precisely wrong’.
In the immediate short term the RLCFR regulators need to provide a better publicly accessible explanation of why they are not including iLUC. This explanation should be accompanied with an implementation plan that clearly states milestones and methods for generating iLUC factors to be incorporated into the RLCFR Regulation.
There are numerous reasons to remain optimistic that technological innovation will enable the goals of the RLCFR Regulation to be realized. It is becoming increasingly clear that carbon capture and storage systems will need to be integrated with oil sands related processing units, upgraders and refineries. For instance, results from Cai et al. (2015) indicate that around 16.3 to 39.7 g CO2eq/MJ diesel occurs during the oil sands recovery (9 to 30.1 g CO2eq/MJ diesel) and refining (7.3 to 9.6 g CO2eq/MJ diesel) processes. If CCS units can create even a 50% net reduction in these life cycle emission sources, then B.C.’s increasingly stringent CI limits will be easier to reach.
B.C. needs to continue research, development and provide economic incentives until regional waste wood and agricultural residue-based diesel/ethanol (i.e. 2nd generation biofuels) can be generated at a commercial scale. Generating fuels from such sources have proven to exhibit substantially lower life cycle GHG emissions (in the range of ‐5 to 30 g CO2eq/MJ) than their petroleum counterparts and iLUC is not a significant issue (Chum et al., 2011).
One of B.C.’s big transport related GHG solutions resides in electric mobility. Given B.C.’s vast quantity of hydro power resources and a correspondingly low electricity grid CI, the Government of B.C. has a great opportunity for incentivizing the increased adoption of personal electric vehicles (PEVs). The commercial availability of PEVs is global, and with an already developed and expanding network of charging stations, B.C. is ripe for increasing PEV share in the personal motor vehicle fleet. Smart meters could also be used to account for domestic EV charging and thus increase measured GHG emissions reductions from personal EV transport in B.C. However, caution and analysis is required to ensure PEVs do not end up as just a secondary family vehicle (due to the currently low mileage per charge) and PEVs do not significantly displace more GHG friendly modes of transportation, like bus (trolley), sky train, bicycling and walking.

For a full list of references and more details please contact us…



Ecogamut Consulting – helping you achieve your sustainability goals

At Ecogamut, making sustainability metrics work for you is the bread and butter of our operation. Our toolbox of expertise includes life cycle assessment, environmental product declaration, carbon footprinting, carbon offsetting, and climate change adaptation strategies. With a team of Ph.D.-level experts you can be rest assured that Ecogamut will deliver a high quality and high impact product that will effectively direct your organization or jurisdiction towards its most cherished sustainability goals.
Have a sustainability project on your mind and think we can help? Contact

Changing your Diet Could Have Huge Land Use and Greenhouse Gas Implications

We all have within our power an incredibly effective way of reducing our planetary impacts:  embarking on your sustainability diet pathway. The concept is quite simple. Every person needs to take stock of their current diet and better understand two things: firstly, what impacts do your foody habits have on the planet; and secondly, what can you change in your diet to significantly reduce your food induced environmental footprint.

To illustrate the diet direction that we all ought to consider, I rely on a recent study that modelled our planetary impacts in the year 2050 with the very important assumption that our human population reaches nine billion inhabitants. The authors of this study simulate a planetary ecosystem and economy where the entire human population of Earth is on one of the following five diet variants as listed here:

  1. A reference diet, meaning our business-as-usual recent diet trends which encapsulate the good, the bad and the ugly of our regionally diverse, highly inequitable and majority high meat content that our diets have become.
  2. A ‘Healthy Diet’, as defined by the Harvard Medical School. This diet allows you to consume all meat sources (avoiding processed meats) in moderation while the bulk of your calorific intake should consist of fruits and vegetables. The Healthy Diet, and subsequent diets below, emphasize the need to eat in moderation avoiding any excessive over-eating habits.
  3. A no ruminant diet, is quite similar to the Healthy Diet only now no ruminant based meat (e.g. beef,  goat, sheep, buffalo) is allowed in your diet.
  4. A no meat (i.e. vegetarian) diet, where only dairy based animal products are permitted in your diet.
  5. A no animal (i.e. vegan) diet, meaning only plant/fungi based foods are permitted.

This study, entitled ‘Climate benefits of changing diet’, ensured that with the reference alternatives, every one of the nine billion human beings on the planet projected in 2050 would be nourished in a healthy and equitable fashion. Therefore, the reference alternatives (diet variants 2-5 above) would lead to a much healthier global population than our currently unbalanced food system. These four diet variants (2-5) can be seen as a sustainability diet pathway to embark upon, because in the equivalent order that these diets are presented above, they lead progressively towards less environmental impacts. The results from this study are actually quite amazing and I’ve illustrated the main findings in this short video below (please share!).

Certainly the models used to generate these astounding results require simplifying a great number of assumptions. However, the models utilized are among the best global integrated assessment models available in the world relying on years of research and refinement. The authors also undertook a number of sensitivity analyses to ensure their main findings were robust. Even if these findings are half the magnitude as they were presented, there is still ample justification to assume that these four diet variants progressively achieve less planetary impact in the proposed order as listed above.  Therefore, these diet variants provide us with an easy rule of thumb to follow if we wish to strive to achieve a diet that is considerably better for the planet.

Some of you may also be wondering what about fish? Although fish consumption was not modeled in any of the reference alternatives, this high protein meat sources generally has a life cycle environmental impact falling somewhere between chicken and pulses (like soy). (see above video for further context). However, as with most complicated systems in life, the devil is in the details. If your fish is flown halfway around the globe before landing on your plate, impacts can sky rocket towards similar greenhouse gas emission per unit protein as beef sources. So beware! The eat local mantra should be practiced to the best of your ability.

Back to those devils in the details: what major limitations do you feel need to be addressed in such an analysis? We’d all be thankful to hear your words of insight, caution, or skepticism.

LCA Inc: A brief history of life cycle assessment in the corporate world

LCA’s Beginnings

The initial seeds of LCA’s conception reach back as far as the 1950s when ideas about bioeconomics and systems ecology were formalized in Samuel Ordway’s ‘Resources and the American Dream‘ and Eugene and Howard Odum’s ‘Fundamentals of Ecology‘. However, most LCA practitioners track LCA’s humble beginnings back to the year of 1969 when Coca Cola hired the MidWestern Research Institute to conduct a material and energy flow study of their packaging alternatives. The study consisted of a comparative analysis between returnable glass bottles, primary aluminium and plastic alternatives. Harry Teasley, the Coca Cola executive who initiated the study was conscious of the need for environmental knowledge for both internal planning purposes and for public relations. Study findings suggested that plastic measured far better than the other alternatives, however, it took a number of years before Coca Cola began the switch to plastic. The MRI defined their technique as “Resource and Environmental Profile Analysis” and it was based on a “cradle to grave” systems analysis of the production chain of the investigated products.

This led to LCA’s period of conception throughout the 1970s and 1980s (spilling into the early ’90s) during a time when environmental issues such as resource and energy efficiency, pollution control and solid waste management became important to the public at large. During this time firms applied diverging life cycle techniques largely for the purpose of substantiating market claims. This time of uncoordinated efforts often led to competing firms challenging one another’s products where studies of the same products often saw widely differing results (e.g. the cloth vs. disposable diaper debates between the pro-cloth National Association of Diaper Services and pro-disposable Proctor & Gamble).

The early to late 1990s ushered in a decade of LCA standardization and convergence where a number of workshops, forums and published academic articles began to appear. This decade began to see international coordinated LCA involvement with the likes of the International Standards Organization (ISO) and the Society for Environmental Toxicology and Chemistry (SETAC). ISO eventually harmonized the LCA process with the still current ISO standards, ISO 14040 and ISO 14044. LCA then became far more credible and corporations began to adopt the technique more readily.

What LCA is, and what LCA is Trying to be

Highly esteemed science writer Daniel Goleman predicted that LCA would be a major game changer. In his book entitled ‘Ecological Intelligence‘ he described how LCA practitioners could measure material and energy flows and associated environmental impacts of products with ‘near-surgical precision’. In reality LCA actually measures only the potential environmental impact and tends to fall far short of attaining a high level of certainty in the final results. Since the global economy is essentially connected across vastly complex supply chains, the very concept of LCA’s cradle-to-grave analysis entails the accounting of essentially everything; this however, is an impossible task. The technique rather involves the application of scientific based modelling to account for the most prominent processes in a given value chain so that the major or most likely hot-spots of the system are guaranteed coverage.

Many see LCA as the essential accounting technique to sound and sober sustainability decision making. As stated in the ISO standard 14040, LCA is a technique that considers ‘the entire life cycle of a product or service and all attributes or aspects of natural environment, human health and resources’. The major insights that LCA can provide an organization about their products or services are two fold: firstly, LCA objectively ascertains exactly where the environmental hot-spots of the value chain are located (often in very unexpected places); and secondly, LCA examines several environmental impact categories such as climate change, ozone depletion, resource scarcity, acidification and human toxicity and this allows for an analysis of possible trade-offs between two or more competing functionally equivalent products or designs. LCA then becomes particularly useful in the initial design phase of a product, service or policy. As LCA advances, LCA Practitioners are always trying to reach towards the impossible task of modelling the global economy in its entirety and this pursuit likely won’t letup anytime soon.

LCA’s Big Break in the Corporate World: Walmart

Walmart had concocted a dream of undertaking 10,000 or so LCAs in order to attain a detailed LCA of every single product that they sold. With the finances to back this vision Walmart broke into the LCA world with a lot of enthusiasm and momentum. In July 2009 they announced their ‘Sustainability Index‘ that would cover a product’s entire life cycle, from resource extraction through to disposal. This led to what is now termed the Sustainability Consortium which currently boasts more than 80 corporate members, operates on four continents and since late 2012 has worked with the much larger Consumer Goods Forum to establish ‘a globally harmonized science-based approach to measure and communicate life cycles‘. There are a number of similar green initiatives around the world where LCA has gained a high degree of popularity. What was once a rather unpopular, academic and dare I say geeky system of accounting turned into the go-to approach for corporate and government initiatives to measure, disclose, inform policy and improve existing products’ cradle-to-grave environmental impacts. The corporate supply chain itself has become a breeding ground for knowledge and insight of a company’s operations and its big picture implications.

For the majority of LCA’s existence, it has for the most part been situated in a place where academics told industry that LCA will benefit you and therefore you should utilize it. With the initiatives of Walmart it really helped to open the flood gates of LCA application, where it is now industry that inquires with LCA consultancies that they need that tool. LCA has reached a renaissance where even the big four (Deloitte, PwC, Ernst & Young, and KPMG) have adopted it into their toolbox along with many other specialized consultancies (like Ecogamut!) where they are finding a growing demand.

LCA in industry has not been a total success however. The methodological rigor required to undertake a detailed LCA brings upon several challenges with industry: LCAs can be time consuming and cost thousands of dollars to undertake; LCAs can become too complicated for the public and results do not always turn out in favor of the companies best financial interest; more supply chain transparency can lead to greater vulnerability and potentially moral disquiet. These challenges can lead to industry misuse of LCA, which in turn harms its reputation. A notable quote from Oscar Wilde, “The truth is never pure and rarely simple” and many LCA practitioners struggle to avoid the muddy waters of complexity, data gaps and what the funding corporation wants to hear.

Signs that LCA is Here to Stay

Despite this industry unease, LCA has already proved itself to be a popular tool in both the corporate and governmental world. There are a great number of signs that LCA is thriving and will likely only get better. All companies face rising resource costs, and many are dealing with growing pressures for transparency requiring that they account for and better manage both the environmental and social impacts throughout their supply chain. LCA is one of the best tools to provide this transparency and it also protects companies from the accusation of ‘greenwash’. European Union regulations now require lawmakers to apply life cycle thinking when undertaking waste management decisions. Many European governments have looked to LCA to inform them about key policy decisions covering key sectors as recycling, public transport, food labeling and renewable energy production.

In the United States, both federal and California biofuel standards draw on LCA results. It is common practice for greenhouse gas emission reduction initiatives to require an LCA framework for quantifying reductions. China, Chile, New Zealand and others are investing in LCA research programs and LCA database development, not only for their own benefit, but in anticipation of an encroaching need to better inform global corporations of their upstream impacts. Similar to the nutritional content label of food products, hundreds of companies are utilizing LCA to substantiate their product’s environmental product declaration in a certifiable and third party verified fashion. LCA has even received extensive coverage in top-ranked journal Science, where they published their June 2014 issue on the sustainability of global supply chains.

Supply chains are likely to remain a focus of corporate knowledge production and public reporting. Citizens globally have gained an insatiable demand from corporations to see demonstrable and measurable evidence that they are making progress toward supply chain sustainability. This demand may soon become a requirement, and even if it doesn’t, LCA will remain to be an important technique towards reaching the goals of a sustainable world.

How Clean Would Site-C Hydro Power Be?

As most citizens of British Columbia realize by now, the Site-C hydro power project along the Peace River has been approved by both the Federal and the Provincial Government. After reading the aforementioned approvals I noticed the project was always referred to as being the “Clean Energy Project”. This notion of clean they refer to is commonly understood as being due to the operation phase of hydro power not requiring any solid fuel substrate to convert into electricity and therefore does not emit undesired air emissions during energy conversion such as particulate matter, nitrogen oxides, sulphur dioxide, dioxins and heavy metals. The Site-C project’s level of ‘cleanness’ can also be referred to in terms of life cycle greenhouse gas emissions which is an important metric when comparing several power production alternatives. I became very curious to understand, how ‘GHG-clean’ would the Site-C project likely be.

GHG Intensity of Site-C Hydro Power as Calculated

Well, it turns out Site-C hydro power would likely be quite clean. Upon reviewing the ‘Report of the Joint Review Panel Site C Clean Energy Project‘ information was limited on how BC Hydro undertook the life cycle greenhouse gas (GHG) analysis of the project. After a little more digging I found the original technical report for which the life cycle GHG intensity of 10.5 grams CO2eq. per kWh (gCO2eq./kWh) is based on. At face value British Columbians should  feel fairly good about this low GHG intensity factor considering natural gas and coal power have GHG intensity factors that typically fall in the range of 350-550 and 900-1200 gCO2eq./kWh, respectively. The IPCC Special Report on Renewable Energy provides the following concise figure explaining life cycle GHG intensity of different power sources as depicted below:


Figure 1: Life Cycle GHG Intensity Ranges for Several Power sources (units: gCO2eq./kWh) (source)


Despite the Site-C hydro power system likely having a low GHG intensity it is a worthwhile exercise to gain at least a simplified understanding of how this 10.5 gCO2eq./kWh factor was derived. The GHG technical report split GHG project emissions into two main categories: hydro power reservoir construction and operation. With a series of sensitivity analyses included, the likely annual average emissions from these two activities were estimated to be 124,600 tonne (t) CO2eq. per year due during the construction phase (for 8 years) and 43,400 tCO2eq. (net) per year during the operation phase (for 100 years). Since the capacity of Site-C is designed to be 1100 Mega-Watts (MW) and the average annual energy generation is expected to be about 5100 Giga-Watt-hrs (GWh) we can calculate the report’s estimated likely GHG intensity factor of 10.5 gCO2eq./kWh:  


10.5 gCO2eq./kWh = (43,400 tCO2eq./yr + 124,600 tCO2eq./yr*8yr/100yr)/(5100 GWh/yr*106kWh/GWh)*106g/tonne


The GHG emissions during the 8 year construction period were due to material requirements, fuel combustion and electricity demand and these emissions contributed 1.95 gCO2eq./kWh to this 10.5 value. The remainder and majority of the GHG intensity (8.5 gCO2eq./kWh) was due to the net GHG emissions that stemmed from direct land use change (emissions that occur during the operation phase). Let’s explore this part of the GHG intensity factor next. 

Net GHG emissions from Land Use Change

The Site-C reservoir requires a significant area to be permanently inundated. Stretching 83 km along the Peace River the surface of the reservoir is expected to span an area of 9,330 hectares (ha) and this would require the flooding of 6,345 ha of land. The figure below shows the land-type breakdown of the land area that would be slated for inundation. 


Figure 2: Breakdown of the land-types to be flooded as a result of Site-C Hydro Project (source)


As shown above the majority of land inundated would be sparse trees while about 570 ha of land to be flooded is considered as cultivated agricultural land. The idea of net GHG emissions attributed to the Site-C project due to inundation was calculated by taking the difference in GHG emissions/sources between the inundation area as it is today and the inundation area upon project completion where operational GHG emissions are estimated across a 100 year operational time horizon. In terms of current land productivity the technical report assumed that apart from the cultivated land there were also livestock/grazing activities considered where a current estimate for beef (1,000 head) and dairy cattle (300 head), swine (300 head), horses (150 head) and bison (300 head) was made. GHG emissions from current activities (i.e. farming) upon areas planned for flooding were then estimated and subtracted from the operational GHG emissions expected from the reservoir over the 100 year life time. The figure below illustrates the possible GHG emission sources from a typical hydro reservoir.


Figure 3: A schematic of the various GHG sinks and sources in a hydro reservoir system (source)


As illustrated in the figure above there are a series of complex mechanisms that need to be considered when estimating GHG emissions and sources. A recent study by Professor Edgar Hertwich attempts to integrate these emissions into a life cycle assessment perspective. Here Prof. Hertwich reviewed and analyzed the generation of greenhouse gas emissions from reservoirs for the purpose of technology assessment, relating established emission measurements to hydro power generation. What he found was the global average emissions from reservoir hydro power are estimated to be around 85 gCO2/kWh and 3 gCH4/kWh. Despite this relatively high average in net GHG emissions (equates to 148 gCO2eq./kWh) the study’s recommended numbers for boreal reservoirs (0.97 kg CO2/m2/yr and 40 g CH4/m2/yr) leads to a GHG intensity factor of 21 gCO2eq./kWh.

These factors suggest that the likely GHG intensity assumed for the Site-C hydro power system might be underestimated though the level of uncertainty in calculating net GHG emissions from a reservoir makes it difficult to say who is more correct. At first glance, I think the Site-C GHG technical report undertook a thorough GIS based site-specific analysis utilizing as much localized data as possible and their likely GHG intensity factor of 10.5 gCO2eq./kWh is probably more accurate because of the details that went into this technical report. All in all, Prof. Hertwich highlighted the importance of this emission source, the major limitations of trying to measure these emissions and the high level of uncertainty involved in these calculations. He also found that the power density (plant capacity divided by reservoir area) of the hydro power plant has a strong correlation with reservoir GHG intensity. He cautioned that any hydro reservoir plants with a power density of around 4 W/m2 or less should be avoided. It turns out that the Site-C hydro power plant would have a power density of 20 W/m2 which is well above this CDM project eligibility boundary that Prof. Hertwich generally agreed with.

Followup Questions

Although I do think the Site-C hydro power system would be relatively clean in terms of GHG intensity I do think it is only fair to explore the alternatives and to better understand their associated GHG intensities. For instance, the Canadian Geothermal Energy Association proposed a more cost effective geothermal power alternative and Clean Energy BC proposed a more affordable small-to-medium scale renewables alternative as well. While these projects suggest less cost to BC tax payers, could these projects also equate to less GHG intensity? Another question on my mind is what about the 570 ha of cultivated land and the additional land required for grazing and livestock activities currently taking place on the to be inundated Site-C project land? In a typical LCA study involving presently productive land use change the GHG emissions due to indirect land use change should also be considered in the GHG intensity calculations. In subsequent blog posts I will explore these followup questions. Please stay tuned.