Units of Measurement
THIS IS THE FIRST LAW OF THERMODYNAMICS.
Energy can neither be created nor destroyed, it can only be converted from one form to another.
KINETIC ENERGY is motion energy.
POTENTIAL ENERGY is energy stored in matter
ENERGY IS MEASURED IN JOULES(J)
- 1 BTU= 1,055 Joules
- 1 Calorie = 4.187 Joules
POWER IS MEASURED IN WATTS (W)
- 1 Watt= 1 Joule/second
- 746 Watts= 1 Horsepower
- 1000 Watts= 1 Kiowatt
JOHN STIVERS – WORK ENERGY POWER –
This video breaks down WORK, ENERGY and POWER into an easily understood explanation.
Well let’s start with work. Physicists define work as a force applied over a distance. If you take an object, say a toolbox and apply a force, 22 pounds of force and you move it two feet, you’ve done 44 foot pounds of work. In metric those units convert to 100 newtons of force, and let’s say we moved it 0.60 of a meter. So we’ve done 60 newton-meters of work. In the metric system that’s referred to as a joule, 1 newton-meter is 1 joule. Continue reading the transcript. http://www.energy-101.org/2011/choose-topic/energy-basics/john-stivers-work-energy-power
(video and transcript link) http://www.energy-101.org/2011/choose-topic/energy-basics/john-stivers-work-energy-power
ENERGY UNITS AND CONVERSIONS
by Dennis Silverman www.physics.uci.edu/~silverma
1 Joule (J) is the MKS unit of energy, equal to the force of one Newton acting through one meter.
1 Watt is the power of a Joule of energy per second
Power = Current x Voltage (P = I V)
1 Watt is the power from a current of 1 Ampere flowing through 1 Volt.
1 kilowatt is a thousand Watts.
1 kilowatt-hour is the energy of one kilowatt power flowing for one hour. (E = P t).
1 kilowatt-hour (kWh) = 3.6 x 106 J = 3.6 million Joules
1 calorie of heat is the amount needed to raise 1 gram of water 1 degree Centigrade.
1 calorie (cal) = 4.184 J
(The Calories in food ratings are actually kilocalories.)
A BTU (British Thermal Unit) is the amount of heat necessary to raise one pound of water by 1 degree Farenheit (F).
1 British Thermal Unit (BTU) = 1055 J (The Mechanical Equivalent of Heat Relation)
1 BTU = 252 cal = 1.055 kJ
1 Quad = 1015 BTU (World energy usage is about 300 Quads/year, US is about 100 Quads/year in 1996.)
1 therm = 100,000 BTU
1,000 kWh = 3.41 million BTU
1 horsepower (hp) = 745.7 watts
GAS VOLUME TO ENERGY CONVERSION
One thousand cubic feet of gas (Mcf) -> 1.027 million BTU = 1.083 billion J = 301 kWh
One therm = 100,000 BTU = 105.5 MJ = 29.3 kWh
1 Mcf -> 10.27 therms
ENERGY CONTENT OF FUELS
Coal 25 million BTU/ton
Crude Oil 5.6 million BTU/barrel
Oil 5.78 million BTU/barrel = 1700 kWh / barrel
Gasoline 5.6 million BTU/barrel (a barrel is 42 gallons) = 1.33 therms / gallon
Natural gas liquids 4.2 million BTU/barrel
Natural gas 1030 BTU/cubic foot
Wood 20 million BTU/cord
CO2 POLLUTION OF FOSSIL FUELS
Pounds of CO2 per billion BTU of energy::
Coal 208,000 pounds
Oil 164,000 pounds
Natural Gas 117,000 pounds
Ratios of CO2 pollution:
Oil / Natural Gas = 1.40
Coal / Natural Gas = 1.78
Pounds of CO2 per 1,000 kWh, at 100% efficiency:
Coal 709 pounds
Oil 559 pounds
Natural Gas 399 pounds
BIO FUELS – ENERGY CONTENT
COMMON BIO FUELS AND THEIR ENERGY CONTENT- See chart…http://www.engineeringtoolbox.com/biofuel-energy-content-d_1356.html
6 OF 55 INTERESTING FACTS ABOUT . . .
Only 10% of energy in a light bulb is used to create light. Ninety percent of a light bulb’s energy creates heat. Compact fluorescent light bulbs (CFLs), on the other hand, use about 80% less electricity than conventional bulbs and last up to 12 times as long.g
There are two basic groups of energy: renewable energy (biomass, geothermal, solar, water, and wind power) and nonrenewable (fossil fuels coal, oil, natural gas, nuclear). Three quarters of the world’s energy is generated by burning fossil fuels.h
Lighting currently accounts for about 20% of U.S. electricity consumption.h
More than 1/5 of the world’s primary energy is used for transport, followed by industry, construction, and agricultures. Much is in the form of gasoline, of which nearly 792.5 million gallons is burned every day.e
A “watt” is a unit of power that measures the rate of producing or using energy. The term was named after Scottish engineer James Watt (1736-1819), who developed an improved steam engine. Watt measured his engine’s performance in horsepower. One horsepower equaled 746 watts.e
A hurricane releases 50 trillion to 200 trillion watts of heat energy. This is as much energy as a 10-megaton nuclear bomb exploding every 20 minutes.b
Countries with World’s Most Oil Reserves e
Countries with World’s Most Natural Gas Reserves e
Countries with World’s Most Coal Reserves e
Countries with World’s Highest Oil Production d
Countries with World’s Highest Oil & Total Fuel Consumption d
Energy Use of Common Household Appliances g
Energy Use of Common Household Appliances g
Sources of Energy g
6 OF 35 CRITICAL FACTS ABOUT . . .
Without the atmosphere to create a greenhouse-type effect, the average temperature on Earth would be just 5° Fahrenheit (F).g
Natural levels of CO2 in the atmosphere have varied throughout history between 180 and 300 parts per million (ppm). Today’s CO2 levels hover around 380 ppm, representing a 25% increase over the highest recorded natural levels.b
Fossil fuel burning currently adds nearly six billion tons of CO2 to the atmosphere every year. Only half of this CO2 is removed by forests and oceans.e
Rampant deforestation currently causes 20% of the world’s global warming pollution by prohibiting the reabsorption of CO2.c
The earth’s atmosphere now contains 40% more CO2 than before the Industrial Revolution.g
The United States represents less than 5% of the world’s population, yet Americans account for 25% of the world’s commercial energy consumption and 22% of the world’s industrial emissions of CO2.e
2 OF 50 INTERESTING FACTS ABOUT . . .
Lying just under the surface of western North Dakota is about 25 billion tons of lignite, enough to supply the region’s coal needs for over 800 years.n
Temperatures drop below 0° F on average of 65 days a year near the Canadian border and 35 days a year in the southwestern part of the state, making it one of the coldest states in the nation. The western parts of both Dakotas are also the windiest area of the United States.i
6 OF 55 INTERESTING FACTS ABOUT . . .
Nuclear Power http://facts.randomhistory.com/nuclear-energy-facts.html
Today, 104 nuclear plants supply about 20% of the United State’s electricity. The oldest plants have been operating since before 1979. There have been no new sites built since the Three Mile Island disaster (1979).a
In the United States, radioactivity is often measured in rems. However, most countries currently use the sievert (Sv) to measure radioactivity. One sievert is equal to 100 rems. The nuclear waste from an entire reactor gives off about 10,000 rems per hour, even 10 years after it was first used in a nuclear plant. A human who is exposed to 500 rems at one time will die.d
Waste from the 1979 Three Mile Island accident is stored in Idaho, even though Idaho has never had a commercial reactor. Illinois has the most spent nuclear fuel of any other state in the U.S. at 9,301 tons. It is followed by Pennsylvania (6,446 tons), South Carolina (4,290), and New York and North Carolina (3,780 tons each).a
The Sun produces an enormous amount of energy from its nuclear reactions that change hydrogen into helium. In the process, the Sun loses over 4 million tons of mass—every second.h
Just removing a person’s outer clothing can remove 90% of the radioactive material after a disaster.f
Before Fukushima Daiichi nuclear disaster in 2011, the International Energy Agency predicted that nuclear plants would add 360 gigawatts of generating capacity by 2035. After Fukushima, the IEA halved those estimates.e
Top Uranium Producers in the World (2006) h
Number of Nuclear Warheads (2007) h
Nuclear Timeline a
6 OF 65 STARTLING FACTS ABOUT . . .
Americans buy over 29 million bottles of water every year. Making all those bottles uses 17 million barrels of crude oil annually, which would be enough fuel to keep 1 million cars on the road for one year. Only 13% of those bottles are recycled. Plastic bottles take centuries to decompose—and if they are burned, they release toxic byproducts such as chlorine gas and ash containing heavy metals.g
More oil is seeped into the ocean each year as a result of leaking cars and other non-point sources than was spilled by the Exxon Valdez.d
Each person in the U.S. produces about 4 pounds (2 kg) of garbage a day.x
A car from 1985 emits approximately 38 times more carbon monoxide than a 2001 model. BMWs were the most environmentally friendly, while Chrysler and Mitsubishi were the worst polluters. Additionally, cars that get better gas mileage also pollute less.t
For every 1 million tons of oil that is shipped, about 1 ton is spilled.d
Los Angeles International Airport emits approximately 19,000 tons of carbon dioxide—a month. The roughly 33,000 planes that fly in and out of the airport each month release about 800,000 tons of carbon dioxide.p
Carbon Dioxide Emissions by Country (2009): Change 2008 to 2009 y
5 OF 22 INTERESTING FACTS ABOUT . . .
Burying coffins also means that 90,272 tons of steel, 2,700 tons of copper and bronze, and over 30 million feet of hard wood covered in toxic laminates are also buried per year. However, a British company called “Ecopod” offers coffins made from 100% recycled paper.b
The United States makes up only 4% of the world’s population, yet it is the number one producer of garbage. In 2006, Americans generated more than 250 million tons of garbage.g Canada produces 31 million tons of garbage per year.
The economic downturn in 2008 was devastating for the recycling industry. Cardboard that sold for $135 a ton in September now sells for $35 a ton, and plastic bottles fell from 25 cents a pound to 2 cents a pound. What once was a multi-million dollar revenue is now turning into a liability for many cities.a Many industries and manufacturers’ demand for scrap, paper and other recyclables, dropped as consumer demand for new cars, houses, and appliances also dropped.
Each year, Americans throw out enough soda pop cans bottles to reach to the moon and back—twenty times.h
Cigarette butts and filters take 12 years to biodegrade. An aluminum can takes between 200 to 500 years to biodegrade. Plastic diapers and sanitary pads take between 500-800 years. Styrofoam takes more than 5,000 years. And it would take a glass bottle 1 million years to biodegrade.h
A single 20-watt compact fluorescent bulb, compared to a 75-watt incandescent light bulb, saves about 550kWh of electricity over its lifetime. If the electricity is produced from a coal-fired power plant, that savings represents about 500 pounds of coal. If every household in Wisconsin replaced one 75-watt incandescent light bulb with a 20-watt compact fluorescent bulb, enough electricity would be saved that a 500-megawatt coal-fired plant could be retired.
How Efficient Is Your Home?
To find out, visit: Home Energy Saver™ (HES).
Btu Content of Common Energy Units
- 1 barrel (42 gallons) of crude oil = 5,800,000 Btu
- 1 gallon of gasoline = 124,238 Btu (based on U.S. consumption, 2008)
- 1 gallon of diesel fuel = 138,690 Btu
- 1 gallon of heating oil = 138,690 Btu
- 1 barrel of residual fuel oil = 6,287,000 Btu
- 1 cubic foot of natural gas = 1,027 Btu (based on U.S. consumption, 2008)
- 1 gallon of propane = 91,033 Btu
- 1 short ton of coal = 19,977,000 Btu (based on U.S. consumption, 2008)
- 1 kilowatthour of electricity = 3,412 Btu
Examples of Converting Different Energy Sources to Btu
You have a natural gas furnace in your home that used 81,300 cubic feet of natural gas for heating last winter. Your neighbor has an oil furnace that used 584 gallons of heating oil last winter. To determine which home used more energy for heating, you can convert the natural gas and heating oil consumption figures into Btu, as follows:
|Natural Gas:||81,300 cubic feet (your house)||x||1,027 Btu per cubic foot||= 83,495,100 Btu|
|Heating Oil:||584 gallons (neighbor’s house)||x||139,000 Btu per gallon||= 80,999,960 Btu|
Answer: You used more energy to heat your house!
You work for an electric power company. Your company’s power generators can run on one of two fuels: natural gas or residual fuel oil. Your job is to switch fuels when the cost of the fuel you are currently using becomes more expensive than the other fuel. This will keep costs down for you and your electricity customers. Your company’s generators are currently using residual fuel oil, but fuel oil prices have been going up much faster than natural gas prices. Based on the fuel costs below, you need to decide if it is time to switch to natural gas:
|Natural Gas:||$7.30 per thousand cubic feet||÷||1.027 million Btu per thousand cubic feet||= $7.11 per million Btu|
|Residual fuel oil:||$57.75 per barrel||÷||6.287 million Btu per barrel||= $9.19 per million Btu|
Answer: When you convert the fuels into the same units, you see that residual fuel oil now costs more than natural gas. You decide to switch to natural gas to save money.