Connecting the dots: The biogenic carbon footprint of power transmission across forested lands

点击翻译按钮获取中文摘要

Hydropower is one off the largest sources of renewable energy. The province of Quebec, in eastern Canada, is an important hydropower producer : over the next years, it intends to reduce its use of imported fossil fuels by accelerating the electrification of its economy and contribute to the decarbonisation of jurisdictions of northeastern United States through increased hydropower exports, which will require significant efforts to increase electricity transmission capacity across the Quebec territory and into the neighbouring markets. Greenhouse gas (GHG) emissions from hydropower are thought to be significantly lower than emissions from fossil energy sources. Although the most recent global and national estimates of the GHG footprint of hydropower takes into account emissions from reservoirs, they usually ignore the biogenic impacts of the transmission system on the land. In Quebec, the transmission network covers 170 000 hectares, including several different types of mostly upland forested ecosystems from boreal forests where most hydroelectric power is produced, to northern hardwoods forests close to demand centres. We propose to quantify the biogenic carbon impact of power-lines on forest land and vegetation. For doing so, we will study carbon stocks and cycling in the soil and vegetation within existing power-line corridors and their bordering forests, and will make projections for areas on which future power-lines are planned in Quebec and across the American border in New England states. This project will provide an important step forward for improving the life-cycle analysis of hydropower, Refining the estimates for the carbon footprint of hydropower will also feed into life-cycle analyses of all processes and products that consume hydro-electricity, thus directly improving the accuracy of GHG quantification assessments, and ultimately climate policies of Quebec and its export markets. Moreover, it will provide empirical evidence for refining both provincial, national and international GHG inventory methodologies related to forest conversion to utility corridors and other types of settlements.