1. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Background

2. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Background
What electricity is used for:
Heating, cooking, cooling, light, sound, computers, communication, entertainment…
Distribution grid:
Our focus

3. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Typical Operation
Fuel is used to produce heat energy
Water is heated and boiled to steam
High pressure steam enters and spins turbines
(Turbines convert steam into mechanical energy)
Turbines turn electrical generator (electricity is created)
Electricity is transmitted via cables through power grid 2 1 5 3 4

4. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Power Plants – Power Stations
Alternative Operation
Alternative energy source (e.g. water, wind) spins turbines
Turbines turn electrical generator
Electricity is transmitted via cables through power grid 1 3 2

5. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Non-renewable
Fossil Fuel Power Plant – Coal
Prime mover is steam turbine
Flue gas exhausted to atmosphere
Waste heat released to atmosphere – cooling towers
2nd law of thermodynamics – not all heat can be converted into mechanical form to do work, some heat will be wasted
A power plant cannot be 100% efficient

6. Power Plants – Power Stations
Types of Power Stations – Non-renewable
Fossil Fuel Power Plant – Coal (cont.)
Flue 7 5 4 1 3 6 2
Waste Heat

7. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Power Plants – Power Stations
Types of Power Stations – Non-renewable
Fossil Fuel Power Plant – Petroleum and Natural Gas
Prime mover is gas turbine

8. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Power Plants – Power Stations
Waste heat (options):
Cooling Towers: Released to atmosphere
Combined Cycle: Recycled in secondary boiler

9. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
TERTIARY LOOP
SECONDARY LOOP
PRIMARY LOOP
Cooling water from outside source; gets hot as it condenses steam
Released in cooling tower
Nuclear Power Plant
Closed-loop reactor
Control rods inserted to decrease chain reaction (control rods absorb neutrons, which slows reaction)
Heated reactor water boils secondary loop of water in boiler (steam generator)
Steam spins turbine
Electricity generated to grid

10. Containment Structure
IOT POLY ENGINEERING
3-7
Steam Turbine
Generator
Condenser
Cooling Tower
Containment Structure
Reactor
Boiler
Nuclear Power Plant (continued)

11. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Renewable Energy
Solar Power Plant
Total solar energy absorbed by earth in 1 hour is more than world uses in a year
1 year of solar energy is as much as twice the amount of energy derived from all non-renewables on Earth
All renewables (except geothermal) derive energy from the Sun (e.g., wind, biomass, hydro, wave…)
Sun’s warmth and light
Passive collection – capturing warmth and light through design
Active collection – using technology to transform solar energy into electricity

12. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Renewable Energy
Solar Power Plant – PASSIVE COLLECTION
Architecture – designing structures
Face buildings south
Solar water heating

13. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Renewable Energy
Solar Power Plant – PASSIVE COLLECTION (cont.)
Agriculture – growing food
Fruit walls (trap heat and accelerate ripening)
Timed planting cycles
Drying chicken manure
Greenhouses

14. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Renewable Energy
Solar Power Plant – PASSIVE COLLECTION (cont.)
Other Uses
Water treatment – UV filter
Cooking – focuses heat directly or creates steam

15. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Renewable Energy
Solar Power Plant – ACTIVE COLLECTION
Photovoltaics (PV)
Photovoltaic Effect – converts light into electric current
1880s – first solar cell
1958 – first significant application – Vanguard I satellite
1960s – PV established power source for satellites
Hamau Solar Park, Germany

16. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Renewable Energy
Solar Power Plant – ACTIVE COLLECTION (cont.)
Concentrating Solar Power (CSP)
Use lenses, mirrors, trackers to focus large area of sunlight into small beam
Solar troughs – most cost-effective
Parabolic reflector – most efficient

17. Power Plants – Power Stations
Types of Power Stations – Renewable Energy
Solar Power Plant – ACTIVE COLLECTION (cont.)
Concentrating Solar Power (CSP)
Solar tower – traps heat, creates steam for turbines
Solar updraft tower – combines chimney, greenhouse, wind turbine

18. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Renewable Energy
Wind Power Plant
Sun influences weather processes that create wind
Converts wind energy into electricity using turbines
History
>5,500 yrs ago – sailboats and natural ventilation
600s, Afghanistan – vertical shaft mills grind grain
1100s, Europe – horizontal shaft mills grind wheat
U.S. – used for irrigation

19. Sketch and label this diagram
Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Renewable Energy
Wind Power Plant (cont.)
Blades – propellers mounted on masts are pitched (angled)
Gear Box – connects low-speed shaft to high-speed shaft to increase rpm from ~50 to ~1200
Generator – converts mechanical energy of high-speed shaft to electrical energy
Sketch and label this diagram
Mast

20. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Renewable Energy
Hydroelectric Power Plant
Gravitational force of falling water converted into electricity using turbines
History
>2000 yrs ago, Rome and Greece – grinding wheat into flour
1700/1800s – powered textile and industrial mills
1882, Wisconsin – first hydroelectric plant

21. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Renewable Energy
Hydroelectric Power Plant (cont.)
Dam stores water in reservoir
Energy generation depends on head – height difference from top of reservoir to top of river – and volume
Spillway releases excess water
Gate releases dam water into penstock – screen prevents objects from damaging turbines
Penstock is piping – pressure of water increases

22. Power Plants – Power Stations
Types of Power Stations – Renewable Energy
Hydroelectric Power Plant (cont.)

23. Power Plants – Power Stations
Types of Power Stations – Renewable Energy
Hydroelectric Power Plant (cont.)

24. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Renewable Energy
Geothermal Power Plant
Harnessing energy generated from heat stored in Earth
History
Hot springs used for centuries for bathing and heating
1911, Italy – world’s first and only plant until 1958

25. Power Plants – Power Stations
IOT POLY ENGINEERING
3-7
Types of Power Stations – Renewable Energy
Geothermal Power Plant (cont.)
Steam or hot water pumped from underground to turn turbines
Waste steam/water returned to ground or reused

26. Power Plants – Power Stations
Types of Power Stations – Renewable Energy
Tidal Power Plants

27. Power Plants – Power Stations
Types of Power Stations – Renewable Energy
Wave Power Plants – 2 types
Linear Generator