INNOVATION July-August 2016

Culliton Run-of-River Hydroelectric Project The 15-megaWatt Culliton Hydroelectric Project is a run-of-river development located 20 kilometres north of Squamish, BC. Engineering design and project management was by Canadian Projects Limited, with TetraTech EBA (geotechnical) and Prime Engineering (electrical). The project includes several distinctive design components: the headworks feature a three-stage sediment exclusion system to manage high-sediment load and extreme flow events using a steel sheet-pile sediment basin (R ight ) and weir spillway structures. Other major project improvements resulted in significantly reduced earthworks and concrete volumes over the previous design, a singular safe access point from the busy Sea to Sky Highway, averted weather-related construction impacts, improved energy yield, and higher flood passage capability—at substantial cost savings. The project was constructed in just 16 months, with completion in December 2015, ahead of schedule.

Automation Upgrade at Atlantic Power Bio-Energy Facility Atlantic Power Corporation is a co-generation power plant in Williams Lake, BC, that converts forest waste biomass to electrical power. Reliability challenges and risk from equipment obsolescence and associated power-supply uncertainty prompted the company to replace its legacy distributed control system (DCS). By working with Spartan Control, Atlantic Power reduced the upgrade’s complexity and replaced the entire DCS in three phases within short- scheduled maintenance windows over a two-year span, with minimal disruption to power generation. Repurposing of existing healthy equipment and upfront audits by site personnel reduced upgrade costs, yet ensured the new technology improved maintenance, reliability, and performance.The team also tested and accepted all implementation aspects prior to deployment to ensure rapid project completion. Overall, the plant realised a savings of $850,000 from the original cost estimate, is now able to easily expand the existing system by 20 percent, and has improved access to plant-process diagnostics to ensure availability and reliability of power delivery.

McLymont Creek Run-of-River Hydroelectric Project The McLymont Creek Hydroelectric Project, located on a tributary of the Iskut River, is a 66-megaWatt run-of-river scheme owned by AltaGas Ltd. Project components include an intake for diverting a maximum of 30 cubic metres per second of power water from

the creek, a 2.8-kilometre-long conveyance tunnel, a powerhouse with three Francis turbines, a substation, and 9.5 kilometres of transmission line. Gygax Engineering Associates (GEA) led the multi-disciplinary team that provided engineering design and construction-phase technical support for the project. GEA’s team included Struthers Technical Solutions, Northwest Hydraulic Consultants, CM Rock Engineering, Wyllie & Norrish Rock Engineers, BGC Engineering, and Golder Associates. The innovative intake arrangement provides the required power flow diversion and flood and sediment passage, while accommodating site-access constraints. The tunnel has rock overburden of up to 780 metres. The project was completed on budget. Power generation began October 2015, nine months ahead of schedule.

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