Electricity Generation Methods and Power Plants

Understanding Power Generation Systems

Dams and Hydroelectric Power

A dam is a concrete structure typically sited on the riverbed, perpendicular to its direction, designed to retain water to elevate its level and form an artificial lake or reservoir.

Types of Dams:

• Gravity Dams: The force of the stored water is countered by the dam's own weight.
• Arch Dams: These dams, shaped like an arc, are fundamentally anchored into the river's side walls, transmitting the forces of water containment.

Dams are equipped with gates and overflows, which serve as damping elements. In the deeper part of the dam are the drainage outlets.

Hydroelectric Power Generation:

The engine room houses turbo-alternators with various turbine types:

• Pelton Turbines: Used for high altitude and regulated flow.
• Francis Turbines: Suitable for medium flow and variable flow.
• Kaplan Turbines: Ideal for very low heads and high, variable flow.

Pumped-Storage Power Plants:

These facilities are designed to optimize electricity production based on demand. They consume surplus energy during off-peak hours (valley hours) by pumping water uphill and supply energy to the system during peak hours.

• Pure Pumping: Dedicated to pumping.
• Mixed Pumping: Combines pumping with conventional generation.

Thermal Power Plants

Conventional thermal power plants generate electricity through the combustion of coal, fuel oil, or natural gas. Power plants designed to use different fuels, such as coal and natural gas, are called mixed thermoelectric plants.

Key Components of Thermal Power Plants:

• Boiler
• Turbine
• Condenser
• Cooling Tower
• Chimney
• Main Electrical Equipment Room
• Feedwater Treatment

Some thermal power plants also produce electricity while harnessing waste heat to obtain hot water for heating or steam for other industrial needs, depending on the area's requirements. These often use gas turbine or diesel engine modules.

Nuclear Power Plants

A nuclear thermoelectric plant uses the energy from the fission of uranium and plutonium atoms as its primary source.

The Nuclear Reactor:

The nuclear reactor is the most important component, constituting the core of the plant. It is the system that allows for the production and control of sustained chain reactions, utilizing the thermal energy generated to obtain steam that drives the turbine, which in turn powers the electric generator.

Parts of a Nuclear Reactor:

• Reactor Vessel
• Moderator
• Control Rods
• Coolant

Types of Nuclear Reactors:

• Pressurized Water Reactor (PWR): These reactors use enriched uranium as fuel and water as both coolant and moderator. The heat produced in the core is transferred through a primary cooling circuit to a secondary circuit to produce steam.
• Boiling Water Reactor (BWR): Also using enriched uranium, BWRs differ from PWRs by using only one cooling circuit. Steam is generated directly inside the reactor as the water boils under pressure. This design is simpler.
• Fast Neutron Reactors: These reactors do not use a moderator because the fission neutrons produced by the nuclear reaction are fast. To maintain the reaction, the amount of fuel per unit volume is much higher than in thermal reactors.

Other critical components include the containment building, the turbine, and fuel control systems.