In the spring of 2019, Business Elite Canada profiled BC Hydro’s massive dam and hydroelectric generating stating project known as Site C.
Started in July 2015, Site C will be on-line by 2024, and will deliver British Columbia with 1,100 megawatts of dependable capacity and generate about 5,100 gigawatt hours of energy each year. That is an additional eight percent capacity—enough to power the equivalent of 450,000 homes.
Two years—and one pandemic—later, we followed up with on the project’s progress with David Conway, Community Relations Manager, Site C Clean Energy Project
Q: Since 2019, there has been a great deal of progress. First things first, how did the Covid Pandemic impact construction, and how did you overcome these challenges?
A: COVID-19 has had significant impacts on the Site C project. BC Hydro’s top priority is the safety of its employees, workers and members of the public. In March 2020, we had to scale back the workforce in camp by about 50 per cent. This was done to reduce the number of people staying in our worker accommodation and limit the number of people travelling to and from the Peace region.
The project focused its attention on the activities to achieve river diversion, along with other essential work such as keeping the site safe and meeting our regulatory commitments.
BC Hydro also stopped work for several months in a number of areas including the dam and core buttress, earthfill dam, and generating station.
Prior to COVID-19, Site C remained on schedule to go into service in 2024. Due to the reduction in workers in the camp accommodation lodge resulting from the pandemic, the project missed about 60 per cent of the 2020 summer construction season for the dam and core buttress, earthfill dam, and generating station and spillways.
As a result, the project’s expected in-service date has been delayed a year and the project budget increased to $16 billion. The largest cost increase is the estimated costs related to the COVID-19 pandemic, which includes an extra year to complete the project and other COVID-19 related costs.
Q: Please tell me about the River Diversion. Why is this a major project milestone?
A: One of the most important steps in building Site C is to reroute a short section of the Peace River during construction. Diverting the river allows us to build the earthfill dam on dry land across the main river channel, while keeping the river flowing.
Preparations began in 2018 when we started excavating two diversion tunnels on the north bank of the Peace River. Measuring approximately 750 m long and 11 m wide, the tunnels are able to pass 3,000 m3 of water a second. We completed the diversion tunnels in early 2020.
Due to fluctuating river flows and the changing needs of our upstream generating facilities throughout the year, diverting the Peace River could only occur in late summer / early fall. Diversion took place in September 2020 over a period of several weeks and was successfully completed on October 3, 2020. This allowed us to focus on building up the upstream and downstream cofferdams – which measure about six stories high -– across the main channel. We then pumped the remaining water out of the area between the cofferdams, creating a dry area to build the centre of the Site C dam.
Q: What remains to be done for the completion of the Project?
A: The Site C Project is about 50% complete. Major components of the project that remain to be completed include the earthfill dam, the powerhouse with the six turbines and generators, the spillways, the second 500 kV transmission and the highway 29 realignments. All of these components are in varying stages of construction.
Q: What will the completion mean for BC Hydro and the people of BC?
A: Site C will provide 1,100 megawatts of capacity, and produce about 5,100 gigawatt hours of electricity each year — enough energy to power the equivalent of about 450,000 homes per year in B.C.
BC Hydro is building Site C to meet the long-term electricity needs of our customers. Once built, Site C will be a source of clean, renewable and affordable electricity in B.C. for more than 100 years. BC Hydro’s clean, renewable energy is key to reaching CleanBC’s targets and gives the province an advantage over jurisdictions that rely heavily on fossil fuel generation.
Q: What is the economic impact of the project?
A: Construction is providing significant opportunities for employment and for businesses of all sizes. The latest employment statistics show that there were 5,046 total workers on the Site C project in June 2021. Of the total workers, 3,573 were from British Columbia, or 71%. Almost all of the remaining workers, approximately 30% are coming from other locations in Canada.
Construction will contribute $3.2 billion to provincial gross domestic product (GDP), including approximately $130 million to the regional GDP. During construction, Site C will result in a total of $40 million in tax revenues to local governments and, once in operation, $2 million in revenue from grants-in-lieu and school taxes.
Q: When will the 4 remaining turbines arrive from Brazil? Please talk about the logistics of shipping such large entities.
A: The four remaining runners for the Site C generating station are being manufactured in Sao Paulo, Brazil, by Voith Hydro, who was awarded the turbines and generators contract in March 2016.
Voith Hydro is forecasting delivery of all four remaining turbine runners to Prince Rupert, BC about October 2021. They are expected to arrive at site around the end Feb 2022.
The turbine runner is the rotating part of a turbine (like a fan or a windmill) that converts the gravitational energy of falling water into mechanical energy, which then spins a generator to produce clean hydroelectric power. The runners are the heaviest unassembled single project components. Each runner weighs approx. 170 tonnes and measures approx. 26 feet (8 m) wide and 17 (5 m) feet tall.
The runners will leave by ship from the Port of Santos, Brazil and it will take about six weeks for them to arrive at the Port of Prince Rupert. The turbine runners are off loaded in Prince Rupert and trucked one at a time by road using a special truck and trailer unit that can handle the weight of the turbine. The trailer is 81 metres long x 7.98 metres wide (267’ L x 26’ W). A convoy is made up of one truck in front of the trailer and two push trucks in the rear. In addition, there are three traffic control cars, three pilot cars and two supervisor cars accompanying the shipment. It takes about a week for the turbine runner to travel the approximately 1,150 kilometres from Prince Rupert to the project site southwest of Fort St. John.
Q: Are there any other things you would like to highlight at this time?
A: The Site C substation was placed into service and the first of two transmission lines was energized in October 2020; these transmission lines connect Site C to the rest of the BC Hydro system through the Peace Canyon generating station.
The Site C Project continues to face significant challenges that have materially impacted the project cost and schedule. In February 2021, the Government of British Columbia (B.C.) announced a revised cost estimate to complete the Project of $16 billion, along with a new expected in-service date of 2025, as a result of the delays and impacts of the pandemic.
The need for foundation enhancements on the right bank, along with other cost pressures prior to COVID-19, have also contributed to the increase. In June 2020, the B.C. Treasury Board approved the new budget of $16 billion and the new in-service date of 2025.
There are significant challenges relate to geotechnical issues on the right bank. By early 2020, BC Hydro had determined that significant foundation enhancements were required to increase the stability under the structures on the right bank, including the powerhouse, spillways and future dam core area.
BC Hydro has identified a two-part solution to improve the stability of the right bank structures: extend the foundation deeper into the rock; and reduce the amount of groundwater that could accumulate within the bedrock foundation. Independent dam experts have confirmed BC Hydro’s proposed foundation enhancements solution is appropriate and sound, and will make the right bank structures safe and serviceable over the long operating life of Site C.
www.bchydro.com/energy-in-bc/projects/site_c.html
