Page 4 of 7

4. Hydroelectric Power & Geothermal Energy

Both hydroelectric and geothermal energy systems provide dense, highly reliable, and dispatchable energy baseloads. While solar and wind are non-dispatchable variable renewables, hydro and geothermal offer key system grid balancing services.

4.1 Hydroelectric Generation Infrastructure

Hydroelectric facilities convert the gravitational potential energy of elevated water bodies into electrical energy through hydraulic turbines (Francis, Kaplan, or Pelton designs). Hydropower setups are classified into three primary operational topologies: Impoundment Systems: Large-scale reservoir dams controlling stored water release to meet dispatch energy demands.

Run-of-River Systems: Flow-through facilities diverting river flows through turbines, minimizing flooded upstream footprints.

Pumped Storage Hydropower (PSH): Closed-loop grid storage setups that pump water up to elevated reservoirs during off-peak hours and release it during high demand.

Grid-Scale Storage Dominance: Pumped Hydro

Pumped Storage Hydropower (PSH) accounts for over 90% of total installed global utility grid energy storage capacity worldwide. PSH delivers long-duration storage, system inertia, fast ramping capabilities, and grid frequency regulation support.

4.2 Geothermal Energy Harnessing

Geothermal power extracts natural thermal energy stored in the Earth's subterranean crust. Steam or hightemperature fluids are accessed via deep production wells (1 to 5 kilometers deep) to drive power generation equipment.

Dry Steam Power Plants

Flash Steam Plants

Directly draws underground steam reservoirs through

Pumps deep high-pressure hot water into low-pressure

turbines. The simplest, most direct geothermal power

surface tanks, causing fluid to flash into steam that

generation architecture.

drives generation hardware.

Binary Cycle Plants

Enhanced Geothermal (EGS)

Passes moderate-temperature geothermal fluid through

Injects high-pressure fluid into deep dry rock formations

a heat exchanger to boil a secondary organic fluid with a

to

lower boiling point.

geographic access.

Renewable Energy Technologies: Comprehensive Overview

manufacture

artificial

permeability,

expanding

Page 4 of 7