The Geothermal Power Station · AI Generator #GEN-CC8C79E1
Physics · thermodynamics
Problem
A geothermal power station operates by extracting hot water from underground reservoirs and using it to drive a heat engine. The station pumps water from a geothermal well at temperature Th=180°C and rejects waste heat to a nearby lake at temperature Tc=15°C. The power station is designed to extract Qh=50MW of thermal energy per second from the geothermal source.
(a) What is the maximum theoretical electrical power output of this geothermal station?
(b) In practice, the actual power station achieves only ηactual=12% efficiency. How much waste heat per second does the station dump into the lake?
(c) If the lake has a volume of V=2.0×106m3 and the station operates continuously, by how much would the lake temperature rise per day if there were no other heat transfer mechanisms? (Use ρwater=1000kg/m3 and cwater=4180J/(kg⋅K).)