Power generation

Question 1

What are the main types of power generation technologies?

Answer 1

Fossil fuels (coal, natural gas), nuclear, hydropower, wind, solar, biomass, and geothermal.

Question 2

What is the Rankine Cycle?

Answer 2

A thermodynamic cycle used in steam power plants where water is heated to steam, spins a turbine, and is then condensed.

Question 3

How does a combined cycle power plant improve efficiency?

Answer 3

By using both a gas turbine and a steam turbine, capturing waste heat to generate additional power.

Question 4

What is a gas turbine?

Answer 4

A turbine where air and fuel are mixed, ignited, and expanded to produce rotational power.

Question 5

How does nuclear fission generate power?

Answer 5

Energy is released by splitting uranium atoms, heating water into steam to drive turbines.

Question 6

What is the thermal efficiency of a coal-fired power plant?

Answer 6

Typically around 33-40%, limited by heat loss in the Rankine cycle.

Question 7

What is a capacity factor?

Answer 7

Ratio of actual energy produced to the maximum possible energy over a period.

Question 8

How does a solar photovoltaic (PV) panel generate electricity?

Answer 8

Converts sunlight into direct current (DC) electricity through the photovoltaic effect.

Question 9

What is the Betz limit for wind turbines?

Answer 9

The theoretical maximum efficiency for wind energy capture, 59.3%.

Question 10

How does a geothermal power plant work?

Answer 10

Uses heat from the Earth’s crust to generate steam and drive turbines.

Question 11

What is cogeneration (CHP)?

Answer 11

Combined Heat and Power generates electricity and captures waste heat for other uses.

Question 12

What is the difference between base load and peaking power plants?

Answer 12

Base load plants run continuously (e.g., nuclear), while peaking plants operate during high demand (e.g., gas turbines).

Question 13

How do tidal power plants generate electricity?

Answer 13

Captures energy from tidal movements using turbines.

Question 14

What is the typical efficiency of a wind turbine?

Answer 14

Around 35-45%, limited by Betz’s law and mechanical losses.

Question 15

What is the heat rate in power generation?

Answer 15

The amount of fuel energy required to generate 1 kWh of electricity, often measured in BTU/kWh.

Question 16

How does a hydroelectric dam generate power?

Answer 16

Water stored in a reservoir flows through turbines, converting gravitational potential energy into electricity.

Question 17

What is a peaking power plant?

Answer 17

A power plant designed to operate during periods of high electricity demand.

Question 18

How does a Stirling engine generate power?

Answer 18

Converts heat into mechanical work through the cyclic compression and expansion of a gas.

Question 19

What is an open-cycle gas turbine (OCGT)?

Answer 19

A gas turbine where exhaust gases are not reused, commonly used for peak power demand.

Question 20

What is the principle of operation for a biomass power plant?

Answer 20

Organic materials are burned to produce heat, generating steam to drive turbines.

Question 21

How does the efficiency of a nuclear plant compare to a gas plant?

Answer 21

Nuclear plants have lower thermal efficiency (~33%) but operate at a high capacity factor.

Question 22

What is the principle of ocean thermal energy conversion (OTEC)?

Answer 22

Uses the temperature difference between surface and deep ocean water to generate electricity.

Question 23

What is the efficiency range for a combined cycle gas turbine (CCGT)?

Answer 23

Typically 50-60%, among the most efficient fossil fuel systems.

Question 24

What limits the efficiency of coal-fired plants?

Answer 24

Heat losses, incomplete combustion, and the Rankine cycle’s thermodynamic limitations.

Question 25

How does a wave energy converter work?

Answer 25

Captures kinetic and potential energy from ocean waves and converts it to electricity.