Today

1. Today Electric Power Lecture Carbon Trading Game Assignment 2 posted Thursday Electric Power Distribution and Storage Lecture Homework 3 (Conservation) due at start of class Group homework using eQUEST One homework/group Discuss Homework 3 Present an example problem to help with Homework 4 At 6 pm, reading quiz for Electric Power due

2. Country Name Sustainable Energy Problem ## Problem Statement and schematic: In the college of engineering many hallway lights are on when sunlight is available to light the hallways. There are lighting systems which turn lights on when the ambient light level drops below a given value, and turn them off when ambient light levels exceed the given value. Estimate the amount of energy (in kW-hr) that could be saved next month if the mechanical engineering wing used one of these lighting systems. Figure 1: Map of the engineering center1

4. Week 4 Electricity Generation, Transmission, and Storage

5. 37 % 38 % 25 % 11 % 13 % Why Care?

6. 16.3% 0.83% 39.9% 0.37% 15.7% 19.3% 0.0033% 6.9% 0.0033% 0.40% International energy agency, 2003 water turbine steam turbine steam turbine gas and steam turbines steam turbine Includes wind Where is this electricity coming from? How is it created?

7. So, what are we going to talk about most of the day?

8. Salt Lake holds 16 km3 of water Steam Trivia: How much water do we (earthlings) change to steam every year in the name of electricity demands? A. 10 km3 B. 55 km3 C. 6,000,000 m3 D. 190,000,000 m3

10. 1306 1712 1890 Running out of accessible supply. Coal mines had to stop at the water table. mine water table coal 1500s 1603 1661 1700 1776 1880 1900 1200 Britain producing 5x more coal than rest of the world. 1948 1963 1942 1969 1940 1950 1960 1967 1970 1911 1920 2002 2004 1976 1988-92 1978 1982 1987 2001 2003 future 1973 1996-97

11. 1306 1712 1890 1500s 1603 1661 1700 1776 1880 1900 1200 1st Newcomen engine (steam engine) was installed at a mine, to pump water out so they could dig deeper. 1948 1963 1942 1969 1940 1950 1960 1967 1970 1911 1920 2002 2004 1976 1988-92 1978 1982 1987 2001 2003 future 1973 1996-97 And, humans crossed the threshold.

12. control volume zero (on average) electrical energy chemical potential energy of coal 33% 67% 1st Law of Thermodynamics: How do we analyze? Energyin – Energyout = ∆Energycv & heat

13. Closed Cycle Reversible Heat Engine workout turbine generator boiler heatin electricity fuel air condenser workin pump heatout Tpond Most efficient type? Carnot no heat constant s no work constant P Tboiler no heat constant s no work constant P Steam Engine External Combustion Engine

14. Ambient water (or air), Tpond = 10 °C For coal-fired power plants, maximum Tboiler = 600 °C For nuclear power plants, maximum Tboiler = 300 °C We keep reading that steam power plants are closer to 33 % efficient. Why the discrepancy? What is the Carnot efficiency? Reversible closed cycle involving a two-phase substance cannot realize the Carnot efficiency.

15. workout 3 turbine heatin boiler 4 2 workin condenser pump 1 critical point 3 heatout qboiler,in constant pressure lines wturb,out 2 wpump,in 4 1 qcond,out What is this plot describing? Saturation Dome for Water/Steam T Rankine Cycle compressed liquid superheated vapor saturated liquid & vapor s

16. workout 3 turbine heatin boiler 4 2 workin condenser pump 1 3 heatout 2’ 1’ 4’ How do we improve efficiency? Increase area of shape 1234 T Problems: Pmin lower condenser pressure 2 4 1 s

17. workout 3 turbine heatin boiler 4 2 workin condenser pump 1 3’ heatout 4’ How do we improve efficiency? Increase area of shape 1234 T superheat steam to higher T 3 Problems: Tmax Qin limits 2 4 1 s

18. workout 3 turbine heatin boiler 4 2 workin condenser pump 1 heatout 3’ 2’ 4’ How do we improve efficiency? Increase area of shape 1234 T increase boiler pressure 3 2 Add Reheat 1 4 s Can we fix this?

19. workout 3 turbine heatin boiler 4 2 workin condenser pump 1 heatout How do we improve efficiency? Increase area of shape 1234 T 5 Preheat feedwater 4 6 3 2 Regeneration 7 1 s

21. workout turbine generator boiler heatin electricity fuel Tboiler air condenser workin pump heatout Tpond

22. (O2 + N2) CO2 + H2O + NO + SO2 + N2 coal + air products + heat CH0.67O0.043N0.010S0.003 heating value of coal = 24 – 35 MJ/kg Combustion

23. CH0.67O0.043N0.010S0.003 1.152 (O2 + 3.7 N2) complete combustion Toxic & PM friend Moles of O2 per mole of C = ½ (2 + 0.33 + 0.010 + 0.006 – 0.043) = 1.1515 Toxic & ozone friend Greenhouse gas No worries incomplete combustion More (1-x) CO2 + x CO + 0.33 H2O + (0.010+y) NO + 0.003 SO2 + (4.261-y) N2 + PM Toxic Toxic coal + air products + heat + No worries CO2 + 0.33 H2O + 0.010 NO + 0.003 SO2 + N2 4.261 + mercury

24. If we were to use the numbers from that study, along with western air pollution values … (50) (100) (310) (110) (860) (450) (200) (1560) Total = 3500 deaths/year (1200-6200 – 95% confidence)

25. Heat Heat Heat Exchangers You tell me – how efficient can you make a heat exchanger? How do you get this efficiency?

26. Internal Kinetic Turbines You tell me – how efficient can you make a turbine? How do you get this efficiency? Design

27. Turbine picture

28. Valmont Power Station !91 MW from coal-fired steam Boiler operates at 21 MPa and 534 °C The condenser is at