Hydroelectric Power Calculator

Hydroelectric Power Calculator

Estimate the power output and revenue of a hydroelectric installation from basic flow characteristics. This calculator supports three turbine types — dam, run-of-river, and tidal — and uses standard hydropower formulas with water density ρ = 998 kg/m³ and gravitational acceleration g = 9.81 m/s².

Dam turbine formula

Dams convert the potential energy of falling water into mechanical energy. The power output is:

$$P = \eta \times \rho \times g \times h \times Q$$

Where η is turbine efficiency, h is the head (usable fall height in meters), and Q is the flow discharge calculated as cross-sectional area A times flow velocity v.

Run-of-river and tidal turbine formula

Installations without a significant head use the kinetic energy of flowing water:

$$P = 0.5 \times \eta \times \rho \times Q \times v^2$$

Run-of-river systems need a steady inflow, while tidal turbines harness the rise and fall of ocean tides.

Revenue estimation

Annual revenue is calculated from the power output in kilowatts, your electricity tariff, and operating days:

$$\text{Revenue} = \text{tariff} \times P_{\text{kW}} \times 24 \times \text{operating days}$$

Example calculation

A dam with cross-section 150 m², flow velocity 2 m/s, head 15 m, and 80% efficiency:

$$Q = 150 \times 2 = 300 \text{ m}^3/\text{s}$$

$$P = 0.8 \times 998 \times 9.81 \times 15 \times 300 \approx 35{,}245 \text{ kW}$$

At $0.08/kWh over 150 operating days, annual revenue would be about $10.1 million. For related renewable energy tools, see the Rainwater Collection Calculator or the Carrying Capacity Calculator.