Geothermal & Hydroelectric Energy - Vocabulary Flashcards

Vocabulary flashcards covering key terms related to geothermal and hydroelectric energy from the notes.

Geothermal energy

Thermal energy derived from the Earth’s interior; heat trapped inside the core and conducted to the surface; a renewable resource.

Etymology of geothermal

Geo = earth; thermal = heat.

Renewable resource

A natural resource that can be replenished on a human time scale, such as geothermal, hydro, wind, solar, and biomass.

Hydroelectric energy

Electricity generated from moving water, typically using dams, turbines, and generators; also called hydroelectric power.

Hydropower

Energy derived from water moving under gravity, converted into electricity.

Peaking plant

A power plant designed to respond quickly to peak electricity demand, delivering power in minutes.

Magat Dam

Major hydroelectric dam between Isabela and Ifugao, Philippines; reservoir, dam, intake gates; owned by NIA; mainly for irrigation but also provides power.

Agus Hydropower

Hydropower facilities on Mindanao (Agus River) providing electricity.

Reservoir

A large artificial or natural lake used to store water for energy production and irrigation.

Dam

A barrier built to hold back water and create a reservoir.

Spillway

Structure in a dam that safely releases excess water.

Intake

The point where water enters the turbine system from the reservoir.

Penstock

A conduit carrying water from the reservoir to the turbines.

Turbine

A machine that converts kinetic energy of moving water or steam into mechanical energy.

Generator

A device that converts mechanical energy into electrical energy.

Transformer

A device that changes electrical voltage for transmission.

Transmission lines

Wires that carry electricity from power plants to consumers.

Power house

Building housing turbines and generators in a hydroelectric plant.

Fishway

Passage that allows fish to migrate around a dam.

Palinpinon-1

Geothermal power plant in Valencia, Negros Oriental; part of Negros Island geothermal facility.

Negros Oriental Geothermal Powerplant

Geothermal facility in Negros Oriental; contributes to Visayas renewable energy capacity.

Direct heat conduction

Heat transfer from hot rock to circulating fluid by direct contact.

Bubble-like magma buoying

Magma rising toward the surface, transferring heat to near-surface rocks.

Rapid magma injection into deep natural rifts

Process delivering heat to the surface by injecting magma into deep fractures.

Production well

Well that extracts hot geothermal fluid from underground.

Injection well

Well that re-injects cooled geothermal fluid back into the reservoir.

Heat exchanger

Device transferring heat from geothermal fluids to another fluid or circuit.

Cap rock

Impermeable rock layer above a geothermal reservoir that traps fluids.

Two-phase flow

Simultaneous flow of steam and liquid water in a geothermal system.

Steam turbine

Turbine driven by high-pressure steam to rotate a generator.

Condenser

Device that cools steam back to water after it exits the turbine.

Cooling tower

Structure where excess heat is rejected and steam is condensed.

kWh (kilowatt-hour)

Unit of energy equal to using 1000 watts for one hour.

CO2 per kWh (emissions factor)

Approx. 1.5 pounds of CO2 emitted per kilowatt-hour for coal-fired electricity.

Geothermal energy advantages

Renewable; no harmful gases emitted; abundant heat source.

Geothermal energy disadvantages

Availability limited to regions with accessible magma or heat; relatively low electrical efficiency (around 10–12%).