Plutonic Power Corporation and GE Energy Financial Services have signed a memorandum of understanding to partner on a bid to develop approximately 1,000 megawatts (MW) of clean, run-of-river hydroelectric capacity in the Toba and Bute Inlets along the southwest coast of British Columbia. With approximate capital costs of US $4 billion, the joint investment would be the largest single private sector investment in hydroelectric generation in Canada.
Plutonic Power and GE Energy Financial Services intend to jointly bid the Upper Toba Valley and Bute Inlet Projects into the 2008 BC Hydro Clean Power Call Request for Proposals in November. Based on current assumptions, if the two entities’ joint bid is accepted, GE Energy Financial Services intends to make an equity contribution of US $70 million for a 50% interest in the Upper Toba Valley Project and either by itself, or with other partners, an equity contribution of US $650 million for a 60% interest in the Bute Inlet Project.
The Upper Toba Valley Project, a series of three sites with a capacity of approximately 120 MW and the Bute Inlet Project, a series of 18 sites with an approximate capacity of 900 MW, are currently in the permitting and review stages of the Environmental Assessment Process.
Run-of-the-river hydroelectricity is a type of hydroelectric generation whereby the natural flow and elevation drop of a river are used to generate electricity. Power stations of this type are built on rivers with a consistent and steady flow, either natural or through the use of a large reservoir at the head of the river which then can provide a regulated steady flow for stations down-river
Power stations on rivers with great seasonal fluctuations require a large reservoir in order to operate during the dry season, resulting in the necessity to impound and flood large tracts of land. In contrast, run of river projects do not require a large impoundment of water. Instead, some of the water is diverted from a river, and sent into a pipe called a penstock. The penstock feeds the water downhill to the power station’s turbines. Because of the difference in altitude, potential energy from the water up river is transformed into kinetic energy while it flows downriver through the penstock, giving it the speed required to spin the turbines that in turn transform this kinetic energy into electrical energy. The water leaves the generating station and is returned to the river without altering the existing flow or water levels.
Most run-of-river power plants will have a dam across the full width of the river to utilize all the river’s water for electricity generation. Such installations will have a reservoir behind the dam but since flooding is minimal, they can be considered “run-of-river”.
Flooding the upper part of the river is not required as it doesn’t need a reservoir. As a result, people living at or near the river don’t need to be relocated and natural habitats are preserved, reducing the environmental impact as compared to reservoirs.
– from Renewableenergyworld