Run of River hydroelectric technology uses the natural flow of water from a river to produce electricity. It has no associated large dam or reservoir. Run of River hydroelectric projects are dramatically different in design, appearance and impact from conventional hydroelectric projects. There are two main differences. First, there is no water storage other than the limited amount required to submerge the intake pipe. Second, there is no alteration of downstream flows, since all diverted water is returned to the stream below the powerhouse.
In Run of River hydroelectric, a portion of the river's flow is diverted to a powerhouse before the water is returned to its natural watercourse. The water reaches the powerhouse through a tunnel or penstock, which drops from the intake. Once the water reaches the powerhouse, it is at a very high pressure and is directed into a turbine before it is fed back into the river. The power generated is connected to a local power grid through a high voltage transmission line.
The environmental "footprint" of Run of River facilities is typically considered lower-impact when compared to large scale hydroelectric facilities that have large water storage reservoirs. With no large dam to alter the river's flow, the design attempts to mitigate the environmental concerns traditionally associated with commercial dam-based hydroelectric projects.
The following illustration demonstrates large scale Run of River hydroelectric technology:
Dasque Middle
The Dasque Cluster is a 20 MW project located approximately 20 km west of Terrace. The cluster consists of two creeks, Dasque Creek and Middle Creek. The site was selected because of the high precipitation regime, and the hydrology has been characterized using a combination of site-collected data and a 42 year continuous flow record from two proximal Water Survey of Canada stream gauges. The hydrology is very good for hydroelectric generation, with pluvial (rainfall), nival (snowmelt) and glacial runoff combining to generate a sustained annual hydrograph. Year-to-year flow variations are generally not substantial.
Environmental field investigations for the Dasque Cluster have confirmed that these creeks are appropriate sites for green power generation. Fish barriers have been identified, mapped, and incorporated into the engineering design, and the projects are not expected to disrupt any valuable salmon habitat. The watersheds have already been impacted by logging, and have existing road access, including access to the intake locations and penstock route alignments.
The proposed point of interconnection is the Skeena Substation, located 19 km to the east along a gently undulating route alignment adjacent to existing roads and a high voltage BCTC transmission line. An existing 69 KV feeder at the substation allows for a very straightforward interconnection.
We expect Dasque-Middle to be completed and in-service in the first half of 2013.
Culliton Creek
Culliton Creek is a 15MW run-of-river hydroelectric project. Veresen is currently advancing this project through the permitting process.
The Glen Park Hydroelectric facility, locatedon the Black River in upstate New York, has a nominal installed capacity of 33MW. This facility operates under a 50-year license issued by the Federal Energy Regulatory Commission, which is scheduled to expire in 2032.
