Geothermal and Hydropower Flashcards
7 cards from real REP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Geothermal and Hydropower flashcards as text
Which type of hydropower turbine is most appropriate for very high head applications (above 300 m)?
Answer: Pelton turbine
Pelton turbines are impulse turbines designed for very high head, low-flow sites, using jets of water striking buckets on the runner to convert kinetic energy to mechanical energy.
What environmental mitigation measure is commonly required at hydropower dams to support fish migration?
Answer: Construction of fish ladders or bypass channels around the dam
Fish ladders (fishways) and bypass channels are required at many dams to allow migratory fish such as salmon to pass upstream past the barrier, a key condition in FERC licensing.
Geothermal gradient refers to which physical measurement?
Answer: The rate of increase in temperature with depth below the Earth's surface
Geothermal gradient is the rate of temperature increase per unit depth in the Earth's crust, typically about 25–30°C/km globally, but much higher in volcanic and tectonic regions suitable for energy extraction.
A small hydropower developer wants to avoid full FERC licensing. Which project size typically qualifies for the simplified 'exemption' process?
Answer: Projects of 5 MW or less at existing dams or natural water features
FERC offers a simplified exemption process for small hydropower projects of 5 MW or less at existing dams or natural water features, reducing regulatory burden while maintaining environmental review.
In geothermal energy, what is the function of a 'separator' in a flash steam plant?
Answer: It separates steam from liquid brine after pressure reduction so steam can drive the turbine
In flash steam plants, the separator uses centrifugal force to separate steam from two-phase geothermal fluid after pressure is reduced, directing steam to the turbine and brine to reinjection or further flashing.
What is the primary advantage of underground (cavern) pumped-storage hydropower over conventional surface reservoir pumped storage?
Answer: Reduced land use and surface environmental impact
Underground pumped-storage systems use excavated caverns as the lower reservoir, dramatically reducing surface land use, visual impact, and siting constraints in areas without suitable natural topography.
Which geophysical survey method is most commonly used to locate subsurface geothermal reservoirs before drilling?
Answer: Magnetotelluric (MT) resistivity surveying
Magnetotelluric surveying measures natural electromagnetic fields to map subsurface electrical resistivity, helping identify conductive hydrothermal fluids and reservoir boundaries before expensive drilling.