Introduction to Energy Concepts. Energy Derived from Green en (in) and ergon (work) – in work...
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Transcript of Introduction to Energy Concepts. Energy Derived from Green en (in) and ergon (work) – in work...
Introduction to Energy Concepts
EnergyDerived from Green en (in) and ergon
(work) – “in work” “Forceful or vigorous language”
First definition - Aristotle “Capacity to do Work”
Modern accepted definition
“Energy is Eternal Delight” William Blake, 1757-1827
Four Basic Forms of Energy Kinetic = 0.5 x mass x speed2
Thermal – energy of vibrating molecules within a material
Electrical – force between electrical charges
Chemical – electrical energy that holds molecules together
Gravitational – also known as “potential energy” – force x distance = weight x height = m x g x h
Nuclear – forces that hold atoms together
Units of EnergyEnergy requires a force. Each form of energy
has it’s own force: gravity, strong & weak nuclear forces, electrical, and kinetic forces.
Kinetic Force = Mass x Acceleration Unit of force = 1 Newton = 1 Kilogram x 1 m/s
Energy is a measurement of work accomplished by a force
Energy = Force x Distance 1 Joule = 1 Newton x 1 Meter
Energy and PowerEnergy is a quantity, like distance.
1 kilowatt-hour = 1000 Watts x 1 hour 1 kilowatt-hour = 3.6 x 106 Joules
Power is a rate, like speed, it is the rate that energy is converted from one form to another. 1 Watt = 1 Joule / Second
Laws of Thermodynamics First Law: In any transformation of energy
from one form to another, the total quantity of energy remains unchanged. “Energy is neither created nor destroyed, it only changes forms.”
Second Law: In all energy changes, the potential energy of the final state will be less than that of the initial state – (useful energy is always lost.) “Lost” energy is usually energy that has been
converted to heat, but it could be noise (kinetic energy of air), or other forms of wasted energy.
EfficiencyThe ratio of the amount of useable
energy obtained to the amount of energy input is the efficiency of a process. This is usually expressed as a percent and
it is always less than 100%.
Energy definitionsPrimary Energy – amount of energy
contained in the initial source of energyDelivered Energy – amount of useable
energy delivered to the customerUseful Energy – amount of energy
attributed to the amount of work accomplished
Where do we get energy from and what do we use it for?
Renewable vs Non-Renewable Solar Wind Biomass Hydro Ocean
Coal Oil Gas Nuclear
Fuel is not getting any cheaper..
1000 years of CO2 Concentration
1000 Years of Temperature Changes
Edgartown, MA - today
Edgartown with 1 m sea level rise
Edgartown with 1 m sea level rise and storm surge from Cat. 2 hurricane
Every Year an Average Coal Plant Releases 3,700,000 tons of CO2 10,000 tons of SO2. 500 tons of particulates 10,200 tons NOx 720 tons of CO 220 tons of volatile organic
compounds (VOC) 170 pounds of mercury 225 pounds of arsenic 114 pounds of lead
And there are over 600 of them in the US.Source: Union of Concerned Scientists: www.ucsusa.org
Types of Pollutants CO2 – Global Warming
CO – Health problem PM –Respiratory and
heart disease, haze SOx – Acid Rain,
respiratory illness, haze NOx – Ozone
formation, acid rain, smog, nutrient loading, global warming
Mercury – Neurotoxin Lead – Neurotoxin Arsenic - Poison VOCs – Numerous
health problems Ozone – Health
problems, damage to flora & fauna
Hundreds of other toxic chemicals