Title: Explain how micro-hydro turbines/generators work.
Course: Renewable Energy (17105) > Section: Understanding Hydrokinetic Energy

Explanation should include

- Pelton wheel
  - uses jet force to create energy
  - water is funneled into a pressurized pipeline with a narrow nozzle at one end
  - water sprays out of the nozzle in a jet, striking the double-cupped buckets attached to the wheel
  - the impact of the jet spray on the curved buckets creates a force that rotates the wheel at high efficiency rates of 70–90 percent
  - available in various sizes and operates best under low-flow and high-head conditions

- Turgo impulse wheel
  - upgraded version of the Pelton
  - uses the same jet spray concept, but the Turgo jet, which is half the size of the Pelton, is angled so that the spray hits three buckets at once--as a result, the Turgo wheel moves twice as fast
  - less bulky, needs few or no gears, and has a good reputation for trouble-free operations
  - can operate under low-flow conditions but requires a medium or high head

- Jack Rabbit turbine
  - a drop-in-the-creek turbine that can generate power from a stream with as little as 13 inches of water and no head
  - output is a maximum of 100 watts, so daily output averages 1.5–2.4 kilowatt-hours, depending on the site
  - sometimes referred to as the Aquair UW Submersible Hydro Generator.

Teacher Resource:

- Microhydropower Systems, U.S. Department of Energy (https://www.energy.gov/energysaver/buying-and-making-electricity/microhydropower-systems)

Process/Skill Questions:

- Which type of generator is most applicable to agriculture usages?
- When is it appropriate to use each type of micro-hydro turbine/generator?
- Which type of turbine/generator is most efficient?