Energyminer Optimizes Its
Micro-Hydropower Plant with SimScale

The Energyfish

This case study presents an analysis of the Energyfish, an innovative micro-hydropower system developed by Energyminer. Utilizing the latest in engineering simulation through SimScale, the Energyfish exemplifies a breakthrough in harnessing riverine hydrokinetic energy. This study explores the intricate engineering processes, simulation techniques, and environmental considerations that underpin its design and functionality.

In the quest for sustainable energy solutions, the Energyfish emerges as a pioneering system. Unlike traditional hydropower, it operates unobtrusively within river environments, harnessing the kinetic energy of flowing water to generate electricity. Engineering simulation is used to refine the technical specifics of its design, including the optimization of hydrodynamic loading, structural stresses, turbine efficiency, and environmental impact assessments.

Design Philosophy

The Energyfish design philosophy centers on minimal environmental disruption and maximal energy extraction efficiency. The unit is predominantly submerged, with a low visual profile, ensuring minimal ecological and aesthetic impact. Key features include:

• Modular design for ease of installation and maintenance.
• Robust anchoring mechanisms to withstand varying flow conditions without riverbed alteration.
• High-efficiency turbine design optimized for riverine flow dynamics.

We have used SimScale to design the Energyfish energy system from first principles. Being able to simulate broad physics including turbine design, hydrodynamic loading, and structural deformations all in one platform in the cloud is a huge advantage to our product development process and to bringing the Energyfish to market.

Chantel Niebuhr

CTO at Energyminer

Technical Specifications and Performance Metrics

• Energy Output: Each unit produces 15 MWh/year, contributing to a collective output of 1.5 GWh/year in a swarm of 100 units with a school-installed capacity of 600 KW.
• CO2 Emission Reduction: A swarm of Energyfish can offset approximately 1,300 tons of CO2 annually.
• Operational Lifespan: Engineered for a service life exceeding 10 years, ensuring long-term energy generation with minimal maintenance.
• Flood Resistance: Unique design features enable the Energyfish to operate effectively even during flood conditions, submerging without compromising functionality.

Environmental Impact and Sustainability

The Energyfish’s design incorporates several features to minimize ecological impact:

• Fish-Friendly Technology: The system is engineered to ensure the safety of aquatic life, with meticulous attention given to turbine placement and operation.
• Ecosystem Integration: The unit’s submergence and silent operation ensure minimal disruption to river ecosystems.
• Carbon Footprint Reduction: The system’s renewable energy generation produces baseload-capable electricity with no CO2 emissions.

Engineering and Simulation with SimScale

All the above features have had to be ‘designed-in’ using careful analysis to balance compromising competing performance requirements. Energyminer faced several engineering challenges including:

• Fluid-Structure Interaction (FSI): The FSI feature allowed for a comprehensive analysis of the interaction between water flow and the Energyfish structure, ensuring optimal hydrodynamic performance and structural integrity. SimScale enabled precise modeling of water flow dynamics, assessing the impact of varying flow rates and directions on the Energyfish.
  • Hydrodynamic Efficiency: Optimizing the shape and placement of the Energyfish for maximal energy extraction with minimal impact on river flow patterns.
• Material Selection: Balancing the need for lightweight yet durable materials to withstand riverine conditions without corroding or degrading.
• Structural Resilience: Designing a structure that could withstand the dynamic loads of river currents. Simulations provided insights into the stress distribution across the Energyfish structure, facilitating the design of a robust yet lightweight frame.
• Turbine Simulation: Detailed computational fluid dynamics (CFD) simulations were used to refine the turbine body design for maximum efficiency and minimal wear.

Exploring Fluid-Structure Interaction with SimScale

A simple workflow in SimScale is used for evaluating fluid-structure interaction in SimScale starting with a CFD flow analysis. The surface pressure results are then downloaded and used to create and apply a pressure 3D varying boundary condition as the input for a structural analysis using a CSV imported file.

The simulation workflow has yielded significant design insights for the structural and material properties used. The team at Energyminer wanted to include a small cut in the frame of the Energyfish to let it fill with water and improve buoyancy. It was important to predict what impact this might have on surface pressure: 

• The initial wall thickness produced areas of high stress and unacceptable levels of deformation. 
• Wall thicknesses were varied to reduce deformations by a factor of 4. 
• Including a cut to allow the Energyfish to fill with water is simulated to allow for additional water stability. 
• The design insights point to an increased wall thickness with a backcut design being an acceptable candidate and should be further validated before physical testing.
• Using SimScale the team visualized iso-volumes of von-mises stresses above a safety factor of 1 MPa to see side by side comparison of any deformations. They found at very low wall thicknesses the deformations were so large that static linear calculations were no longer relevant and had to move to non-linear analysis.

Currently the Energyfish is undergoing extensive physical testing and pilot phase deployment and monitoring. Simulation work is progressing towards predicting transient effects, and understanding the impacts of vortex shedding and the layout of the units to capture the maximum energy from a river.

Chantel Niebuhr

CTO at Energyminer