Question

8. Provide one similarity and one difference between the Francis turbine and the Fourneyron

turbine.
9. The textbook states. "At present the only practicable and economically viable way to store
electrical potential energy in very large quantities is to use it to pump water up a mountain."
How is this viable given that pumping the water up a mountain uses energy for the pumping?
Hint: carefully read page 199 and examine Figure 5.7
10. If efficiency is the ratio of output power to input power (and usually expressed as a
percentage), which of the following is the most reasonable range of efficiency values?
a) More than 100%
b) Less than 100%.
c) Greater than or equal to 100%
d) Between 50% and 150%.

Answer 1

The Francis turbine and the Fourneyron turbine have similarities and differences. Pumped-storage hydropower is a viable method of storing electrical energy. The most reasonable range of efficiency values is less than 100%.

Step-by-step explanation:

8. One similarity between the Francis turbine and the Fourneyron turbine is that both are types of water turbines used for generating electricity from flowing water. One difference is their design. The Francis turbine has a mixed-flow design, which means that water enters the turbine radially and exits axially, while the Fourneyron turbine has a radial outflow design, where water enters and exits the turbine radially.

9. Pumped-storage hydropower is a viable method of storing electrical potential energy because it allows for efficient energy storage and retrieval. When there is excess electrical energy in the grid, it can be used to pump water from a lower reservoir to a higher reservoir. Then, when there is a demand for electricity, the water can be released back down through a turbine, generating electricity.

10. The most reasonable range of efficiency values for a power system is b) Less than 100%. Efficiency is always expressed as a percentage, and it represents the ratio of output power to input power. It is not possible for a system to have an efficiency greater than 100% as that would violate the law of conservation of energy.

Learn more about Hydropower turbine efficiency