some basic concepts of energy kenneth m. klemow, ph.d. wilkes university prepared for fyf 101j -...
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Some Basic Conceptsof Energy
Kenneth M. Klemow, Ph.D.Wilkes University
Prepared for FYF 101J - Alternative Energy
Overview of topics
Basic energy conceptsHistoric phases of energy production
and supplyTerminology pertaining to energy
Basic energy concepts
What is energy?
Ability to do work Physicists distinguish between kinetic and
potential energy Energy comes in different forms
Radiation Mechanical energy Chemical energy Atomic energy Electromagnetic energy Electrical energy Heat energy
How do we measure energy?
Force: Newton (N = kg x m / s²)Energy: Joule (J = N x m)Power: Watt (J / s)
www.sommarskog.se
Is a Joule a lot or a little?
The energy released when an apple falls one meter to the ground.
The energy released as heat by a person at rest, every hundredth of a second.
# one hundredth of the energy a person can receive by drinking a drop of beer.
Some conversion factors
1 calorie = 4.187 J 1 BTU = 1054 J 1 kilowatt hour = 3.60 x 106 J 1 barrel oil equivalent = 6.119 x 109 J 1 ton wood equivalent = 9.83 x 109 J 1 ton coal equivalent = 29.31 x 109 J 1 ton oil equivalent = 41.87 x 109 J 1 quad (PBtu) = 1.055 x 1018 J 1 horsepower = 735.49 W
Laws of Thermodyamics
First law: Energy cannot be created nor destroyed, can only be converted (conservation of energy)
Second law: No energy conversion is perfect; always get some loss as heat.
Energy and power
Power = energy / time 1 watt - 1 Joule / second
Energy = power x time
www.belmont.k12.ca.us
Why is living matter a source of energy?
CO2H2O C6H12O6
Carbon reduction
Energy
Energy
Carbon oxidation
Energy needs
Biblical times Move people and their possessions Agriculture and food processing Build cities Produce clothing Simple chemical transformations (e.g.
metallurgy) Heating
www.uncp.edu
Where did this energy come from?
Animate sources Humans Animals
Low head hydropowerBiomass (woody tissue)
www.uncp.edu
Energy needs
Industrial revolution times Mechanized food production /
consumption Centralized heating Transportation Lighting Textile manufacturing More complex chemical
processes (e.g., glass manufacturing)
mhslibrary.org/
Where did this energy come from?
Animate sources (mainly animals)Low head hydropowerBiomass (woody tissue)CoalPetroleumLow capacity wind
mhslibrary.org/
Why we need energyModern
Transportation (personal vehicles, commercial vehicles, aviation)
Automated production of goods Transport of goods Centralized heating and air
conditioning Lighting Highly complex chemical
processes
content.answers.com
Where does this energy come from?
Coal Petroleum Natural gas Nuclear fission High and low head hydropower Biomass (woody and
herbaceous tissue) Animate sources (mainly
animals) Low capacity and industrial wind Geothermal Solar collection
content.answers.com
Terminology pertaining to modern energy
Renewable vs nonrenewableTraditional vs new energyCommercialized vs non-
commercializedCentralized vs distributed generationOn-grid vs off-grid
Stages of energy flowfrom http://www.fao.org/docrep/u2246e/u2246e02.htm
Primary energy is the energy as it is available in the natural environment, i.e. the primary source of energy.
Secondary energy is the energy ready for transport or transmission.
Final energy is the energy which the consumer buys or receives.
Useful energy is the energy which is an input in an end-use application.
Stages of energy flowfrom http://www.fao.org/docrep/u2246e/u2246e02.htm
energy technology examples
Primary coal, wood, hydro, dung, oil
Conversion power plant, kiln, refinery, digester
Secondary refined oil, electricity, biogas
Transport/transmission
trucks, pipes, wires
Final diesel oil, charcoal, electricity, biogas
Conversion motors, heaters, stoves
Useful shaft power, heat
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