The Standard Modular Hydropower (SMH) project is rooted in a belief that new hydropower facilities and technologies must sustain the important functions of a stream while generating energy at competitive prices.
Click on the boxes below or visit the Publications page to learn more about SMH research.
Environmentally compatible, cost-optimized hydropower
The SMH project contemplates the need for future energy demand to be met with holistic hydropower technologies that provide both energy and environmental benefits. SMH is not an individual technology or a specific facility design – it is a framework for developing new small hydropower projects.
Within the SMH paradigm, small hydropower development begins with the conceptualization of a facility as an integrated system of standardized modules. Both the facility and the modules operate with dedicated functionalities which together maintain the natural function of streams and watersheds. Modularity enables scalability in two ways – at a single site, by combining multiple modules of the same type, and across multiple sites, by using the same module in different locations. This scalability of standard module designs is hypothesized to lower design, manufacturing, development, and operational costs throughout the development lifecycle.
To achieve significant cost reductions, enhanced environmental performance, and greater acceptance, SMH research and development is guided several core principles:
Stream groupings with similar characteristics
Premise: Site classification seeks to assess and define commonalities among stream-reaches to guide the need for and design of modular technologies. It builds upon the concept that module design should be informed by and maintain natural stream functionalities.
Approach: Site classification used multivariate statistical techniques, specifically K Means Clustering, to group stream reaches into clusters defined by commonality among their physical and biological characteristics (Figure 1). Classification of over 300,000 National Hydrography Dataset (NHD) stream reaches was carried out for each module type: generation, water quality, foundation, sediment, fish passage, and recreation. The set of stream reaches was limited only to those with a mean annual flow between 50 and 25,000 cubic feet per second. Clustering variables included local in-stream attributes (ex: mean annual flow, gradient, species present, etc.), landscape features (ex: land use, soil type, impervious surfaces, agricultural practices, etc.), and other local or regional characteristics (ex: population density, existing dam presence, etc.).
Figure 2. A national map shows how site classification was used to define ten clusters that illustrate the variability in sediment characteristics across the country (Figure 2). Sediment clustering variables included % agricultural land in the watershed, stream flow, runoff, impervious surfaces, % sand in the watershed, % clay in the watershed, forested coverage, stream slope, mean water velocity, and erosion potential. These clusters can be used to inform the need and design requirements of different types of sediment transport modules.
Figure 3. A regional view of the predominant clusters for fish passage in the northeastern US reveals three distinct classes of stream reaches based on which migratory species are present and physical stream characteristics. This information should be valuable in reducing the number of different fish passage designs.
Standardized module and facility design
Premise: The Exemplary Design Envelope Specification (EDES) is a flexible, technology neutral framework for creating state-of-the-art modules and SMH facilities. It describes what functionalities must be accomplished by advanced technologies without stating how those functionalities should be accomplished. By focusing on functionality rather than specific design features, the EDES intends to invite competition and innovation within private industry to design within the envelope of acceptable technical, economic, and environmental outcomes.
Approach: An Exemplary Design Envelope Specification document has been created to guide module innovators through the technology neutral design framework. The framework offers design specifications for six modules: generation, fish passage, sediment passage, recreation passage, water passage, and foundation. Each specification defines the objectives, requirements, constraints, and performance measures modules must achieve, with supporting rationale developed from an extensive literature review of academic and industry documents. In addition, the specifications define important functional relationships that quantify the variability and dependencies between hydropower infrastructure systems and natural stream processes. Ongoing work is focused on refining specifications to align with Site Classification outputs and cluster results. In addition, we are engaging in collaborative research and development with small hydropower stakeholders to test and improve the module and facility specifications.
The figure below conceptually illustrates the hierarchical order of watersheds and power systems. The organizing principle of EDES is to acknowledge this hierarchy and align module functionality with stream functionality at a site to achieve energy and non-energy objectives.
Example: An upstream fish passage module may be required to minimize the barrier to migratory fish movement posed by hydraulic infrastructure. The objective of a fish passage module is thus to allow the unimpeded and safe passage of fish across a facility. To achieve this objective, design requirements include the attraction of fish to the inlet, safe and timely passage of fish through the module, and allowance for safe exit of fish back into the river. As with all modules, an interface that allows modules to structurally integrate together is also a requirement. Constraints and measures of performance reflect quantifiable technical, economic, and environmental metrics as indicators of module success. They are technology agnostic and flexible to allow stakeholders, project developers, and technology innovators to move the dial and set specific metrics based on a species of interest with distinct biological limitations.
For more information on the SMH Exemplary Design Envelope Specification, please see ORNL’s technical report on the Publications page.
Exploring standard modularity
Stimulate innovative designs for small, low-head hydropower facilities capable of lowering the capital costs and reducing the environmental impacts of development at new stream-reaches (DE-FOA_0001836)
Develop new, innovative, transformative, modular hydropower technologies that balance performance, economics, and environmental sustainability. Proposed technologies must leverage advanced manufacturing techniques to lower the cost, increase performance, and/or facilitate rapid deployment of these technologies. (DE-FOA_0002080)
flexible taxonomy framework
ORNL is also exploring the 90,000 documented dams in the United States do not generate electricity, that could be attractive targets for hydropower development. Each dam is unique, with a wide range of characteristics including those related to its design, operation, environment, and socio-economic features. ORNL, we are working to develop a framework for breaking the diverse population of dams into smaller, more manageable groups which will facilitate easier evaluation of development opportunities and enable further research.
Given the diversity of NPDs and development opportunities, we propose a flexible framework for classifying NPDs that:
For more information, please review the factsheet.
Prior SMH-funded research also investigated hydraulic testing and validation needs for small hydropower, the results of which are being leveraged to support ongoing scoping of technology testing needs applicable to hydropower, more broadly. In addition, SMH research findings prompted further DOE investigation into geotechnical foundations, resulting in a recently published ORNL Technical Report and the development of the Groundbreaking Hydro Prize.
Design evaluation and optimization
Premise: The development of standardized modeling approaches and simulation techniques for SMH will pave the way for reliable, cost-effective methods for technology evaluation, optimization, and verification. A suite of modeling capabilities for evaluating, predicting, and optimizing the safety, performance, reliability, and cost of SMH facilities, individual SMH modules, and module combinations will enable rapid and comprehensive development of unproven yet high value technologies.
Approach: A Simulation and Modeling Capability report has been developed to identify use cases, capabilities, gaps, challenges and needs related to modeling and simulating SMH technologies. Current modeling capabilities have been identified in terms of the physical processes which occur in natural stream environments, the interactions and responses of SMH structures, and the salient socio-economic features that determine project feasibility. The current gaps and challenges associated with simulating critical SMH processes highlight opportunities to improve the state of hydropower modeling with a goal of increasing small hydropower development while maintaining the power and function of the natural stream. Ongoing work is focused on developing use cases to assess advanced modular designs and develop widely applicable modeling tools.
The diagram below reflects the structure of how simulation use cases, modeling capabilities, and gaps and challenges inform SMH Simulation and Modeling research.
Example: A generation module simulation use case is being formulated to “optimize composite turbine hydraulic efficiency and manufacturing cost trade-offs with respect to turbine blade material and design.” Modeling capabilities in computational fluid dynamics, finite element analysis, and fluid-structure interactions are being leveraged to resolve the hydraulic and structural processes relevant to the use case. Modeling results will be used to develop a design optimization tool for composite turbines.
The figure below illustrates some early-phase computational fluid dynamics modeling of a turbine blade under different operating conditions.
For more information on the SMH Simulation and Modeling Capability, please see ORNL’s technical report on the Publications page.
Safety, performance, and reliability verification
SMH Testing and Validation Capability research is also evaluating the capabilities needed to certify the safety, performance, and reliability of SMH modules. These capabilities will enable validation of design effectiveness at partial or full scale. The SMH Exemplary Design Envelope Specification is used to inform the testing needs and the physical and technical requirements for establishing an SMH hydraulic testing facility. Engagement with federal facility owners will enable identification of test facility candidate sites, and further discussion among the U.S. Department of Energy, federal hydropower agencies, and regulatory agencies may be needed to aid decision making.
In addition, collaboration with industry partners will lead to prototype testing which may leverage ORNL expertise across a wide range of lab capabilities, including application of additive manufacturing (3D printing), composite manufacturing, high-performance computing, power electronics, electric machinery, embedded sensors, and more.
Stay tuned for more information on SMH Testing and Validation.