January 2025
Project Overview
The Pumped Hydro Storage project was a conceptual design study aimed at exploring how excess solar
energy could be stored and reused by pumping water to a higher elevation and later releasing it through a turbine
to generate electricity. The focus was on applying theoretical engineering principles to model system behavior,
evaluate feasibility, and understand the practical considerations of implementing pumped hydro storage on a
residential scale. To support the conceptual work, the team also built a simple physical prototype to illustrate the
core operating principles of the system. This small-scale model served as a visual demonstration of how potential
energy can be stored and converted back into electricity, complementing the analytical and design-focused aspects
of the project.
- Explore the feasibility of using pumped hydro storage as an alternative to traditional battery systems for residential solar energy.
- Apply theoretical engineering principles to design a complete energy storage system without building a physical prototype.
- Model and analyze energy demand, storage capacity, and system efficiency for a typical two-storey home.
- Design key system components — including reservoirs, piping, pump, and turbine — to meet calculated performance requirements.
- Evaluate economic, environmental, and spatial feasibility for residential-scale implementation.
- Gain practical experience in integrating mechanical, electrical, and environmental considerations into a conceptual design.
The design process for the Pumped Hydro Storage project followed a structured engineering approach focused on
applying theoretical knowledge to a realistic renewable energy scenario. The project began with a thorough
analysis of residential energy demand, determining the daily power requirements of a typical two-storey home
and estimating how much solar energy could be stored and reused through a pumped hydro system.
Once the energy requirements were defined, the team developed and evaluated multiple conceptual system layouts.
Each design considered the relative elevation between the water source and the storage reservoir, flow rates,
and the volume of water required to achieve the desired energy output. The design was broken into key subsystems
including the upper and lower reservoirs, piping infrastructure, pump, turbine, and control systems, each of
which was analyzed individually before being integrated into the overall system model.
Engineering calculations were used to size the reservoirs, select an appropriate pump and turbine, and
determine the potential energy storage capacity of the system. Site conditions, such as elevation, available
land area, and freeze prevention requirements, were factored into the design to ensure realistic performance.
To complement the theoretical work, the team also built a simple physical prototype to visually
demonstrate the basic working principles of pumped hydro storage. This model allowed the team to present the
concept more clearly and connect theoretical calculations to a tangible demonstration.
Although the project remained primarily conceptual, the process simulated the real-world steps of designing
a large-scale renewable energy system — from defining objectives and modeling system behavior to evaluating
feasibility and proposing potential improvements. This iterative and analytical approach, combined with a
hands-on prototype demonstration, helped illustrate the practical challenges of scaling pumped hydro technology
for residential use.
After defining the project objectives and developing preliminary system concepts, the team conducted an in-depth
research phase to evaluate the feasibility and effectiveness of different design approaches. This research included
analyzing existing pumped hydro installations, reviewing technical literature on small-scale energy storage systems,
and studying commercial components such as pumps, turbines, and reservoir configurations. Environmental, spatial,
and cost-related factors were also investigated to ensure the proposed solution aligned with real-world constraints.
Insights from this research were then organized into a design evaluation matrix, a decision-making tool
used to objectively compare multiple design alternatives. Each potential solution was evaluated against key criteria
such as energy storage capacity, efficiency, system reliability, environmental impact, spatial requirements,
and overall cost. Each category was assigned a weight based on its importance to the project goals, and designs
were scored according to how well they met those criteria.
The matrix helped the team clearly identify trade-offs between competing design choices and guided the selection of
the most viable system configuration. This structured evaluation process ensured that the final conceptual design
was grounded in research, quantitatively justified, and optimized to balance technical performance with
practical feasibility.
The calculation process involved evaluating key performance metrics for the Pumped Hydro Storage system. This included
determining the energy requirements, component specifications, and the optimal number of solar panels. Below are the
key findings and calculations that guided the design process:
Energy Requirements
| Calculation |
Value |
| Average daily energy usage |
67 kWh per day |
| Solar panel output |
350 W per panel, 4.398 kWh per day |
| Number of solar panels required |
9 panels |
Energy Production and Storage
| Calculation |
Value |
| Total energy production per day |
157.01 kWh (after considering energy loss and turbine efficiency) |
| Total energy required for the system |
104.36 kWh per day (accounting for system efficiency and excess energy to pump water) |
| Total minimum number of solar panels |
14 panels (considering energy needed for pumping water) |
Component Requirement Calculations
| Calculation |
Value |
| Required turbine power |
3.19 kW |
| Required pump horsepower |
22 hp |
| Required flow rate through the system |
31.04 L/s |
| Water needed (for operation) |
177,095 gallons |
These calculations were crucial in determining the overall efficiency and energy production capabilities of the system,
guiding decisions on the sizing of components and the number of solar panels required for sustainable operation.
To ensure the conceptual design was both realistic and technically feasible, the team selected specific components
based on detailed research and performance requirements identified during the design process. Each component was
chosen to meet the calculated energy storage capacity, flow rates, and operational demands of the pumped hydro
system while maintaining compatibility with residential-scale constraints.
Selected System Components
| Component |
Specification |
Function |
| Pump – Franklin Electric 450STS100D8X-0684 Submersible Turbine Pump |
450 GPM, 100 hp, 8-inch diameter |
Absorbs energy from solar panels and transports water from the lower reservoir to the elevated upper reservoir during charging cycles. |
| Turbine – XJ28-6.0DCT4/6-Z Hydro Turbine |
6 kW, 28–40 m pump head, 30–38 L/s flow rate |
Converts the potential energy of falling water into electricity to power the home. |
| Upper Water Tower Reservoir – Concrete, Welded Steel, and Segmented Plates |
170,000 gallons, 35 m above lake surface |
Stores water at an elevated height to provide the gravitational potential energy required for power generation during discharge. |
| Piping – 8" × 20' Plain End Schedule 80 CPVC Pipe |
8-inch diameter, total length of 71.176 m |
Allows water to flow efficiently between reservoirs, the pump, and the turbine, enabling smooth energy transfer throughout the system. |
Together, these components represent a system-level solution optimized for energy storage efficiency and
performance. While chosen primarily for conceptual modeling, their specifications are representative of
commercially available equipment that could be used in a real-world pumped hydro storage installation.
PSH Simple Prototype Overview
The Pump Storage Hydropower (PSH) simple prototype was designed to test the submersible pump's performance under varying duty cycles and different head heights. The primary objective of the prototype was to generate a pump curve that illustrates the relationship between flow rate and pump head at various conditions. This curve is essential for optimizing the pump's efficiency and determining the ideal operational parameters for a fully functioning PSH system.
Prototype Design and Testing Methodology
The prototype utilized a submersible pump powered by a 6V DC supply, with control managed via an Arduino IDE-based circuit using a ULN2003A power relay chip. Testing was conducted across three duty cycles: 80%, 90%, and 100%, with each cycle measured at four different elevations (0.00m, 0.05m, 0.10m, and 0.15m). The flow rate was measured using a 500mL graduated cylinder and a stopwatch to time how long it took the pump to transfer water between two reservoirs. The pump's performance was evaluated based on its ability to move water efficiently under various head conditions.
Data Analysis
The data collected during testing provided important insights into the submersible pump's behavior under different operating conditions. Here's a more detailed breakdown of the analysis:
Impact of Duty Cycle on Flow Rate
One of the primary factors analyzed was the relationship between duty cycle and flow rate. The results showed that as the duty cycle increased, the time taken to fill the 500mL graduated cylinder decreased. This means that the pump delivered more water in a shorter amount of time at higher duty cycles. Specifically:
- At 80% duty cycle, the pump took longer to move the same volume of water compared to the 100% duty cycle.
- At 100% duty cycle, the pump delivered the highest flow rate, making it the most efficient mode for faster fluid movement.
Effect of Head Height on Flow Rate
The head height, or the elevation difference between the pump outlet and the receiving reservoir, was varied across the trials. The analysis revealed that as head height increased, the flow rate decreased. This can be attributed to the increase in gravitational resistance and head loss at higher elevations. As the pump has to work against the gravitational pull to move water to a greater height, the energy required increases, which in turn reduces the flow rate. Key observations include:
- At lower head heights (e.g., 0.00m), the pump was able to deliver water more efficiently.
- At higher head heights (e.g., 0.15m), the flow rate decreased significantly, as expected due to the increased gravitational force.
Reynolds Number and Flow Behavior
Reynolds number is a critical factor in understanding fluid flow behavior. It indicates whether the flow is laminar or turbulent, which can affect the efficiency of the pump. The Reynolds number was calculated at each duty cycle and head height to better understand the pump's performance. The analysis showed:
- At lower duty cycles and lower head heights, the flow tended to be more laminar, resulting in higher efficiency but slower flow rates.
- At higher duty cycles and higher head heights, the flow became more turbulent, increasing friction losses and reducing efficiency.
This suggests that for optimal pump performance, there needs to be a balance between duty cycle and head height, ensuring that the flow remains in the ideal range to avoid excessive turbulence or resistance.
Friction Factor and Pump Efficiency
The friction factor was calculated using a Moody chart, which is based on the flow conditions and the characteristics of the tubing used in the prototype. The friction head (ℎ𝑓) was calculated for each test condition. It was observed that:
- As the elevation increased, the friction factor also increased, contributing to higher head losses.
- Increased friction losses were associated with longer tube lengths and higher flow velocities, which can significantly impact pump efficiency.
Minimizing friction losses by optimizing tubing design and material selection will be crucial in the next iterations of the prototype.
Implications for Prototype Design
The results from these analyses suggest several key design considerations for the next iteration of the prototype:
- Increasing the duty cycle improves flow rate but increases energy consumption. Future designs should balance efficiency with energy costs.
- The tubing path needs to be optimized to minimize elevation-related head losses. Keeping the tubing as straight as possible and reducing excessive height differences will help maintain better flow rates.
- More detailed tests across a broader range of duty cycles and head heights are necessary to complete the pump curve and refine the prototype's performance.
The pumped hydro storage project demonstrated that small-scale energy storage systems can effectively complement residential solar power by converting excess energy into stored potential energy and later regenerating it as electricity. Our findings showed that the system could meet daily household energy demands with an optimized design that balances efficiency, storage capacity, and cost. Engineering analysis confirmed that with the proper selection of pumps, turbines, and reservoir dimensions, sufficient power output can be achieved while maintaining manageable flow rates and minimizing energy losses. Prototype testing further validated key performance trends, including the influence of duty cycle, head height, and friction on system efficiency. Overall, the results highlight pumped hydro storage as a technically feasible and sustainable alternative to conventional battery systems, offering strong potential for integration into future residential energy solutions.