Site C hydro project will produce fewer GHGs than alternatives

  • National Newswatch

The United Nations Climate Change Conference is currently underway in Paris. The conference is a reminder that jurisdictions around the world are seeking to lessen their reliance on fossil fuels to reduce greenhouse gas emissions (GHGs) — particularly when it comes to electricity generation.While most of the world continues to rely heavily on coal-fired electricity, we are fortunate in British Columbia that we have an electricity system that is 97 per cent clean and renewable, thanks largely to our hydroelectric facilities.In B.C. today, hydroelectric facilities on the Peace and Columbia rivers generate about 80 per cent of the electricity required for BC Hydro's four million customers.However, as extensive as BC Hydro's electricity supply is, it will not be enough to meet B.C.'s long-term electricity needs, even when taking into account BC Hydro's ambitious conservation and efficiency targets. The demand for electricity is forecast to increase by 40 per cent in the next 20 years, due to economic growth and a projected population increase of more than one million people. An emerging electric vehicle market could also increase electricity demand in the future.That's why BC Hydro is building the Site C Clean Energy Project. Construction of Site C started this summer and will be completed in 2024. Once built, Site C will provide clean and renewable electricity for more than a century. It will also deliver power to customers at a lower cost than any other option.Of course, all electricity-generation resources emit some greenhouse gas emissions during construction and operations. To better understand this, the potential greenhouse gas emissions from Site C were modelled using Intergovernmental Panel on Climate Change guidelines.The modelling, which considered construction and operations, found that GHG emissions per unit of energy from Site C will be at levels comparable to other renewable sources, such as wind and run-of-river hydro, and substantially less than natural gas, diesel or coal. GHG emissions from Site C will also be among the lowest when compared to reservoirs around the world, due to the relatively small reservoir and its northern location.BC Hydro's modelling and GHG studies were reviewed as part of a federal-provincial environmental assessment process. The Joint Review Panel concluded that: “Site C, after an initial burst of expenditure, would lock in low rates for many decades, and would produce fewer greenhouse gas emissions per unit of energy than any source save nuclear.”The low-GHG profile of Site C was noted in the federal government's environmental approval of Site C, stating that, over the life of the project, Site C is expected to help mitigate the growth in greenhouse gas emissions in Canada by preventing the discharge of between 34 to 76 megatonnes of CO2 equivalent.Another advantage of Site C is that it optimizes existing resources on the Peace River. As the third hydro facility on the Peace River, it will rely on the existing Williston Reservoir for most of its water storage. This means Site C will have a comparatively smaller reservoir than BC Hydro's other major hydroelectric projects for the amount of energy it will produce. And it will enable Site C to generate approximately 35 per cent of the energy produced at the W.A.C. Bennett Dam, with a reservoir five per cent of the size.Another benefit of a new large hydro project like Site C is its ability to support additional integration of intermittent power into the BC Hydro system. Smaller renewable projects — such as wind and run-of-river hydro — are intermittent, meaning that they are not always available to produce electricity (e.g., when there is no wind or when the river is not flowing).Large hydro projects provide dependable and flexible capacity, essentially acting like a big battery. As a result, Site C will be able to increase its generation when intermittent sources are not available and decrease its generation when intermittent projects are available.Although Site C has many environmental benefits, all new electricity-generation projects have environmental impacts and Site C is no different. That's why environmental approval by the provincial and federal governments in 2014 came with stringent conditions to address a number of potentially adverse effects.At the conclusion of the environmental assessment process, however, the federal and provincial governments determined that the environmental effects of building Site C were justified under the circumstances, including producing clean and renewable energy for more than 100 years.Siobhan Jackson is BC Hydro's Environmental and Community Mitigation Manager for the Site C project.