Hydropower Simulation — Class Notes
What it shows
A micro-hydro scheme where water stored in a mountain reservoir flows down a penstock pipe, strikes a turbine inside the powerhouse, spins a generator, and delivers electricity to a house downstream. The house windows light up as power increases. The simulation uses the real hydropower equation: P = ρgQhη (water density × gravity × flow rate × head × efficiency).
The three controls
- Reservoir Head — the vertical drop from water surface to turbine (2–30 m). This is the gravitational potential energy store.
- Flow Rate — volume of water through the turbine per second (0.05–2 m³/s).
- Turbine Efficiency — how much of the water’s kinetic energy is converted to electrical energy (40–95%).
Suggested classroom activity
Predict → Explore → Explain
- Predict first. Before touching the sliders, ask students: “If you double the head, what happens to the power output — does it double, more than double, or less than double?” Repeat for flow rate. Students write down predictions.
- Explore. Students test one variable at a time, keeping the others fixed. They record head, flow rate, and electrical output in a table.
- Explain. From their data, students should notice that doubling head doubles output (linear), and doubling flow rate also doubles output (also linear) — but combining both quadruples it. This directly illustrates how the equation works multiplicatively.
- Discussion question. “Why does the house only partially light up at low flow rates, even with maximum head?” Leads into discussion of efficiency limits and energy transfer chains.
- Higher tier extension. Students calculate efficiency manually: divide electrical output (kW) by the theoretical maximum (ρ × g × Q × h ÷ 1000) and compare to the slider setting. Reinforces the efficiency equation: η = useful output ÷ total input.
Curriculum links (AQA Physics)
- Energy stores and transfers (Topic 1) — gravitational potential → kinetic → electrical
- Efficiency equation (Topic 1)
- Electricity generation and the National Grid (Topic 4)