Preparatory construction work for the new unit is scheduled to start later this year for commissioning by 2010. A call for tenders for the penstocks has already been issued, the company said. Once in operation, the extra unit will bring the total capacity of the plant to 2480MW.

The commencement of work follows BC Hydro receiving approval for the project from the British Columbia Utilities Commission (BCUC) via a Certificate of Public Convenience and Necessity. In June, the project received an Environmental Assessment Certificate and earlier this month it cleared the screening report under the Canadian Environmental Assessment Act.

Approvals for the project set the baseline for future project commissions, BC Hydro said last week. When Revelstoke was built with four units, BC Hydro provided space for an additional two units. IWP&DC understands that BC Hydro is planning for the future addition of the sixth, and final, unit at the plant.

BC Hydro added in a statement that the additional capacity provided by the fifth unit will enable more clean, but intermittent, energy sources to be brought into the province’s electricity grid, such as wind and run-of-river hydro.

A number of run-of-river hydro developments are being pushed in British Columbia, such as by Plutonic Power Corp, which is about to start construction of its East Toba/Montrose Creek schemes.