ENERGY CLASSIFICATION, SOURCES, UTILIZATION, ECONOMICS, AND TERMINOLOGY

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1 FACOLTA DI INGEGNERIA - CLASSE INDUSTRIALE LAUREA SPECIALISTICA IN INGEGNERIA GESTIONALE PIANIFICAZIONE E GESTIONE DELLE INFRASTRUTTURE ENERGETICHE ENERGY CLASSIFICATION, SOURCES, UTILIZATION, ECONOMICS, AND TERMINOLOGY Prof. Ing. Antonio Ficarella antonio.ficarella@unile.it 1

2 ENERGY major advance in civilization have been accompanied by increase in the rate of energy consumption directly related to the level of living (per capita gross national product) the availability of low-cost energy has led to the inefficient utilization of energy disastrous ecological effects 2

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4 some of the countries that have large supplies of low-cost energy are using those supplies as a potential political and economic weapon 4

5 MASS-ENERGY DEPENDENCE energy must be conserved in any process mass and energy must be conserved a kWe power plant 220 tons of coal/h ( tons/year) 1 tons of uranium/year transitional energy: energy can move across system boundaries stored energy 5

6 mechanical, electrical, electromagnetic, chemical, nuclear, thermal energy transitional form of mechanical energy: work potential energy: position in a force field gravitational or inertial force field, compressed fluid, elastic-strain field, magnetic field electrical energy: flow or accumulation of electrons transferred over long distances electrostatic-field energy associated with accumulation of charge inductive-field energy (electromagnetic) associated with the magnetic field established by the flow of electrons 6

7 electromagnetic radiation 7

8 chemical energy exothermic/endothermic nuclear energy radioactive decay fission fusion annihilation: all reactant mass is converted into energy (subatomic particles) 8

9 thermal energy conversion severely limited by 2nd law of thermodynamics sensible-heat storage (increase of temperature) latent-heat storage (isothermal process) 9

10 ENERGY SOURCES income energy from outer space direct solar energy - nondepetable wind thermal gradients in ocean clouds (hydroelectric) ocean waves biomass gravitational energy of the moon (TIDAL) capital energy that already exist on the earth fossil fuels, geothermal, nuclear 10

11 OCEAN THERMAL ENERGY CONVERSION 11

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13 TIDAL POWER total potential: MWe (10% of total) nondepletable relatively pollution-free concern that could effect the tides in surrounding basins the tide has a cycle of about 12.5 h 13

14 GEOTHERMAL POWER there are tremendous reserves 14

15 ENERGY RESERVES renewable or nondepletable sources fossil fuels fissionable and fertile materials fusionable isotopes the amount of energy reserves is strongly dependent on the price of raw energy 15

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20 GROWTH RATES if power increases at the same annual fraction rate: time required to increase by a factor 2: if annual rate 7%, electrical capacity doubled every 0.693/0.07=9.9 years total energy consumed: 20

21 if (t2-t1)=td, E1=E0: in any given doubling period, the total energy consumed in that period is equal to the total energy consumption in all the time prior to the doubling period if new fuel discoveries extend our present known fuel reserves by an order of magnitude of 10, the new fuel reserves will last only 3.31 doubling times unless the annual growth rate is reduiced 21

22 ENERGY ECONOMICS the general public is supportive of systems that protect the environment as long as a system does not have significant costs COSTS: capital (construction, equipment, investment) operational (fuel) 22

23 CAPITAL COSTS future value of an investment Fnt (compounded n times a year) final future value Fmt of periodic payments (power) which are escalated at an annual percentage rate e BREAKEVEN 23

24 large electrical generating stations have a construction period of 3 to 5 years p construction payments of Rpt: i: long-term interest rate j: short term interest rate < i 24

25 OPERATING COSTS unit fuel cost: f=cent/mbtu, HR=heat rate=btu/kwh unit labor cost: AS annul salary, N of workers, Pmax rated power output, CF capacity factor 25

26 combustion-turbine power plant low capital costs high fuel and maintenance costs PEAK POWER DEMAND nuclear and coal fired power plants high capital costs - low fuel costss BASE LOADED: they operate as close to rated capacity to reduce the unit capital cost 26

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28 CAPITAL RECOVERY FACTOR 28

29 POWER SYSTEMS PERFORMANCE FACTORS thermal efficiency and heat rate capacity factor (load factor) availability factor SPINNING RESERVE at least equal to the power of the largest unit if the largest unit trips, the spinning can quickly pick up the load RESERVE CAPACITY of a power grid: total rated capacity of all the units/expected peak load 29

30 TYPES OF POWER SYSTEM base-load power plants 5000 full-power hours/year (capacity factor>57%) intermediate-load power plants peaking units (<2000 hours, <23%) combustion turbines, Diesel engines, pumpedstorage units 30

31 POWER ECONOMIC TERMINOLOGY depreciation the amount of plant investment that can be written off as part of the annual operating costs rate base the sum of all the capital and operating assets of the utility 31