REDi Island: Hydro Heights (Text Version)

This is the text version of the video REDi Island: Hydro Heights. It shows NREL’s virtual REDi Island, and a pumped storage hydropower at work.

[Music plays with animated REDi logo]

Hydro Heights

[Flyover of illustrated mountains with water bodies, trees, and a hydropower facility]

This closed loop pumped storage system provides utility-scale energy storage and generates electricity during periods of peak demand when energy prices are high.

[Aerial view of reservoir and pipes]

Water stored in high elevation reservoir is collected to a lower elevation reservoir by a series of straight pipes.

[Map of upper reservoir, recreational path, turbine feed pipes, turbine station, and lower reservoir]

[Shot of illustrated turbine station shows the step-up transformer, frequency converter, generator/motor, control valve, and turbine/pump]

When power demand rises above the grid’s supply capacity, the control valves are activated, allowing water to flow down the pipes and through a series of turbines.

[Animation of water flowing through pipes and creating energy]

[Shot of upper reservoir]

As water in the upper reservoir is released, it flows through the turbines, creating rotational motion that is converted into electricity by a group of generators.

[Animation of water flowing through pipes and creating energy]

Electricity produced by the generators is transmitted through a transformer and then onto the main grid where it can meet temporary excess power requirements.

Once power demand returns to normal levels, the control valves are shut. This stops water flow to the turbines and electricity production by the generators.

[Animation of control valves shutting down]

[Night view of animation of water flowing through pipes and creating energy]

During periods of reduced power demand when energy prices are low, excess electricity created by other renewable energy sources is used to refill the upper reservoir.

[Shot of upper reservoir]

In this situation, the generators supply reverse rotational motion to the turbines, allowing water from the lower reservoir to be pumped back uphill to the upper reservoir.

[Aerial view of upper and lower reservoirs]

Pumped storage hydropower is the most common type of grid-level energy storage system based on megawatts installed today.

Funded by U.S. Department of Energy, Energy Efficiency and Renewable Energy, Water Power Technologies Office, and NREL. Learn more at #REDiIsland

[Music stops]