Modular Dams for Reduced LCOE Low Head Hydropower

  • Jenna Bailey
  • 11/18/2016 12:00:00 AM
  • View Count 836
Modular Dams for Reduced LCOE Low Head Hydropower

Modular Dams for Hydropower

U.S. Department of Energy (DOE) sponsored studies show that new stream reach hydropower potential in the U.S. is about 460 TWh/yr., but most of the available sites have environmental and social sustainability challenges that can be partly addressed by run-of-river (ROR) projects, which are considered environmentally friendly because of the modest impoundment and the requirement that the flow upstream of the project is matched by the flow downstream. One of the major problems with harnessing this potential is that the levelized cost of energy (LCOE) estimates for ROR low head turbine systems are often 4-5 times the cost of conventional electricity.   While LCOE is highly site-specific, it must be significantly reduced , on average, to take advantage of this generating potential.

Capital costs are a major contributor to LCOE. Conventional low-head turbines alone hover at around $3,000/kW of nameplate capacity, and by the time earthwork, structural engineering, and other project costs are added, costs can exceed $20,000/kW. This fairly high price point hinders the development of the ROR low head hydropower industry. Another critical issue is that most low-head power installations take years to deploy and, when they are no longer needed, leave behind a lasting environmental impact.

Recognizing this problem and opportunity, Littoral Power Systems Inc. (LPS) conceived a modular low head system, scalable for head from approximately 7 to 50 feet, depending on the type of deployment. It offers the major benefit of very low initial cost due to an innovative form factor: the components of the system are mounted, transported and partially deployed in frames that are dimensioned the same as 10- to 40-foot shipping containers, with compatible corner connectors.  The pre-fabricated, standardized modules can clip together at the project site reducing installation time and minimizing down time for maintenance. This unique approach allows ease of shipment, rapid deployment, and simple construction, minimizing site-specific custom work.

Rendering of Littoral modular low head dam

One year ago, the DOE announced nearly $6.5 million dollars in funding research and development projects to advance low impact hydropower technology.  LPS was one of the successful recipients, and the funding is being used to develop and test the concept.  Working in conjunction with Alden, GZA GeoEnvironmental, the University of Massachusetts - Dartmouth, and the National Renewable Energy Laboratory, Littoral is developing a proof-of-concept design for these modules in an integrated dam section.  Alden is performing CFD and FEA analysis, as well as testing a full-size prototype for structural integrity, leak resistance and ease of installation.  Nearly halfway through the funding period, the team has completed conceptual design of modules for the dam, powerhouse, and spillway, each of which uses the same frame design for modularity.


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