The underground power plant has four generating units with a combined maximum capacity of 1,805 megawatts, and on average produces 7,202 gigawatt hours of electricity per year – enough to power about 655,000 households.

The 500-kilovolt switchgear and associated electrical equipment is needed to conduct electricity safely from Mica’s generating units – located 183 metres underground – to above-ground transmission lines.

“BC Hydro is taking important steps to secure our province’s future electricity needs by re-investing in our generating facilities to extend their lifespan,” said Chris O’Riley, BC Hydro senior vice-president of engineering, aboriginal relations and generation. “Maintaining our heritage assets is a critical component in the overall strategy to ensure the province is electricity self-sufficient by 2016, and that clean and renewable electricity generation continues to account for 90 per cent of total generation.”

In addition to maintaining the reliability of the Mica Generating Station, which was built in 1977, the new switchgear will also improve safety and reduce greenhouse gas emissions. BC Hydro awarded the switchgear contract to Mitsubishi Electric Power Products Incorporated after a rigorous two-year planning and tender review process.

The switchgear equipment replacement is a project that will involve the installation of high-voltage equipment while the generating station continues to operate. Construction will be phased to allow the generating station to continue running with only minor disruptions. Another challenge will be the installation of conductors in three narrow 183-to-305-meter long tunnels that carry power from the underground generating units to the above-ground switchgear building.

On-site work will start in the fall of 2010, following completion of the switchgear design and manufacture, and the project will be complete by 2013. All labour for the Mica switchgear project will be hired through the Columbia Hydro Constructors agreement that gives preference to local workers. The project is expected to create between 30 and 40 full-time temporary jobs.