At a glance
The SediCon Gravel Excluder is a gravity-powered system for removing sediment from intakes. By keeping intakes clear, it can help to extend the life cycle of hydropower plants.
Hydropower is the largest source of renewable energy in the world, accounting for roughly 16 per cent of the world’s power supply, and capacity is expected to grow. One of the major challenges facing hydropower is reservoir sedimentation, which reduces storage volume, energy output and discharge capacity, while increasing wear and tear on equipment and load on the dam.
There are several methods of sedimentation management, including sediment excluders that route sediment along the river, bypassing the intake. However, gravel is not normally transported in suspension and gradually accumulates upstream, eventually blocking the intake. The blockage can be prevented by flushing gravel periodically from the intake area. When flushing, power can be lost due to the high level of flushing water consumption.
The SediCon Gravel Excluder is a fixed system that uses gravity as the driving force to maintain clean intakes. The design of the suction head enables it to remove sediments and stones up to the size of the pipe, while at the same time preventing the pipe from being blocked.
The SediCon Gravel Excluder is made of high-density polyethylene (HDPE), a durable, non-corrosive and abrasion-resistant material.
In its basic form the gravel excluder has no moving parts. The open siphon outlet starts operating automatically once the water level rises. No remote control or monitoring is required, and maintenance is minimal. The gravel excluder may also have an additional valve or gated outlet to start operations.
The SediCon Gravel Excluder removes sediments during floods, while there is natural sediment transport in the river, maintaining a biological and morphological balance in the water system. Because gravity is the driving force for the system, it is virtually emission free.
The SediCon Gravel Excluder is highly reliable and very easy to operate. Because the system only uses surplus water, power production is uninterrupted.
The system can be easily adapted to existing structures and is custom designed for each project. The largest system thus far allows stones larger than 1 metre to pass, but larger diameters can be manufactured upon request.
Hydropower produced from reservoirs is the only renewable power source that can balance and support new renewables such as wind and solar.
Global power demand is projected to increase by 60 per cent by 2040. Overall hydropower capacity is expected to increase by 125 GW by 2023. Rough estimates indicate that there is 10 000 TWh/year of available unutilised hydropower potential worldwide.
Established in 1999, SediCon has designed and installed its patented solutions for sedimentation management in 20 countries. The company also offers the SediCon Dredge, SediCon Desander Dredge and SediCon Sluicer.
Tom Jacobsen
Technical director