Oscar G. Torres

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Energy Conversion

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oscargt

I researched and wrote a few energy conversion with all my spare time. My goal was to shed some light on the difference between energy and power…
Hope they help in some way. And please comment if any of my math puzzling:
About Energy
Energy is the amount of work that can be performed by a force.
Types of energy include elastic, kinetic, and gravitational.
About Power
Power is the rate at which energy is consumed over time.
What is a Watt?
A Watt is a unit of POWER, NOT ENERGY which is what confuses most people =) so:

  • Watt = Power (Energy over Time)
  • Energy = Joules
  • Energy = calorie
  • Energy = Amp hour

    • A Watt is equal to the consumption of one joule of energy per second.
    It is best to use Joules as a unit when working with Energy: http://en.wikipedia.org/wiki/Joule
    Energy Storage
    List of different types of storage:

  • http://en.wikipedia.org/wiki/Energy_storage
  • Storage example: 12V, 7Amp Hour battery = 302,400 joules total storage This means:
  • you can use 12 volts at 1 amp for 7 hours
  • you can use 12 volts at 7 amps for 1 hour
  • you can use 6 volts at 7 amps for 2 hours
  • you can use 12 volts at 0.5 amps for 14 hours

    • See more about batteries below (under Batteries)
    Capacitors
    The energy stored on a cap: E = ½(C*V²)
    E= Joules C= Farads V= Volts

  • e.g.
    one 22F capacitor at 2.7V contains 80.19 Joules
    80.19 joule = 80.19 wattseconds = 0.022 275 watthour
    1 watthour = 3 600 joules
    1 wattsecond = 1 joules

    • Ambient Energy
    Solar:
    “The total solar energy absorbed by Earth’s atmosphere, oceans and land masses is approximately 3,850,000 exajoules (EJ 10^18) per year.[11] In 2002, this was more energy in one hour than the world used in one year.

  • http://en.wikipedia.org/wiki/Solar_energy

    • Wind:
    An estimated 72 TW of wind power on the Earth potentially can be commercially viable.

  • Betz’ law
    is a theory about the maximum possible energy to be derived from a wind turbine. It was developed in :1919 by German physicist Albert Betz. According to the rule, no turbine can capture more than 59.3 :percent of the potential energy in wind.
  • http://en.wikipedia.org/wiki/Betz%27_law
  • http://en.wikipedia.org/wiki/Wind_energy

    • Thermal:
    Global terrestrial heat flow is about 45 TW (1 TW = 1012 watts). This is approximately 1/10 watt/square meter (which is about 1/10,000 of solar irradiation).

  • http://en.wikipedia.org/wiki/Geothermal_heat_pump
  • http://en.wikipedia.org/wiki/Geothermal_(geology)

    • Hydro:

  • http://en.wikipedia.org/wiki/Hydroelectricity

    • Tidal:

  • http://en.wikipedia.org/wiki/Tidal_power

    • Wave:

  • http://en.wikipedia.org/wiki/Wave_power

    • Biomass:

  • http://en.wikipedia.org/wiki/Biomass

    • Energy Conversions

  • Bicycle shown to be the most efficient mode of transportation:
  • Bicycle: 0.052 KWh per mile
  • Walking: 0.098 KWh per mile
  • Motorcycle: 0.808 KWh per mile
  • Airplane (747): 0.606 KHh per person per mile
  • Airplane (cessna): 0.57 KWh per person per mile
  • Car: 0.3 KWh per person per mile
  • Subway: 1.02 KWh per passenger per mile
  • Moped: TBD
  • Running: TBD
  • Ship/Freight: TBD
  • Skateboard: TBD
  • Helicopter: TBD
  • Horse: TBD
  • Rollerblades: TBD
  • Conversions: TBD

    • Power Conversion:

  • http://www.numberfactory.com/nf%20power.htm

    • Energy Conversion:

  • http://www.onlineconversion.com/energy.htm
  • 1calorie=1.163 mW h (milliWatt hour)
  • 1 calorie = 4.184 Joules (1 J = 0.23901 cal) (Thermochemical calorie)
  • 1.163 mW h = 4.1868 J exactly

    • Walking:

    A 160 lb person walking at 3.0 mph burns 85 Cal every mile (85,000 kilocalories) or 98.855 watt-hour ( Convert Calories to W/h in MAC Widget)

  • Reference:
    http://walking.about.com/cs/howtoloseweight/a/howcalburn.htm
  • Online Calculator for Calories:
    http://walking.about.com/library/cal/uccalc2.htm

    • Jogging:
    Jogging (5 miles per hour) for a mile @ 155lb weight= 563 Calories
    Skateboarding:
    Person 155lbs= 352 Calories per hour
    Rollerblading:
    Person 155lbs= 800 Calories per hour
    Canoeing:
    160lb person= 256 Calories per hour
    Biking:
    A 150lb person Biking at a Moderate level (12mph) will burn 45 Calories (45,000 kilocalories)
    or 52.335 Watt-Hours each mile they travel.
    Calories Burned in 30 min . . . . . . . . . . 150-lb person . . . 250-lb person
    Bicycling, light effort (10 to 11.9 mph) . . . . . 200 . . . . . . . 340
    Bicycling, moderate effort (12 to 13.9 mph) . 270 . . . . . . . 450
    Bicycling, vigorous effort (14 to 15.9 mph) . . 340 . . . . . . . 570
    Reference:

  • http://www.bikeforums.net/archive/index.php/t-122791.html
  • http://www.nutristrategy.com/activitylist.htm

    • Motorcycle:
    Average Fuel economy is 40-50 mpg.
    energy in fuel(Regular Gasoline), 34.6 megajoules per litre (MJ/l) or 131.134 MJ/gallon.
    One mile (@ 45mpg fuel economy)= 2.91MJ per mile = 808.3334 watthours per mile
    or 695 Calories(kilocalories) or 1 super size serving of McDonald’s french fries.
    Average horse power is 90HP @12,000rpm for a medium size motorbike (500cc)
    1HP= 746W @ 100% efficiency.

  • http://en.wikipedia.org/wiki/Horsepower#Electrical_horsepower
  • http://en.wikipedia.org/wiki/Motorcycles

    • Mopeds
    Average horse power is 3HP @7500rpm and 80mpg fuel economy.

  • http://en.wikipedia.org/wiki/Moped

    • Car

  • 30mpg 4 person sedan.
  • gasoline=131.134 MJ/gallon.
  • 1.09MJ per mile per person

    • Subway

  • 3492 BTU/passenger mile
  • 3 681 791 Joules= 1.02 kilowatt hour
  • Motors Subway cars have a nominal capacity of 200 h. p. each
  • 1 horsepower = 0.746 kilowatts
  • 200 hp = 149.2 Kw

    • Cessna 172R Small Airplane

  • Fuel Capacity – 56 gal, 10.34mpg
  • Range (80% power, 8,000 ft.) – 580 naut. mi.
  • (60% power, 10,000 ft.) – 687 naut. mi.
  • Capacity: 6 w/ pilot
  • 12.68 MJ/ mile
  • 2.11 MJ per mile per person.

    • 747-8I Jet Airplane

  • Speed= Mach 0.855, 570 mph,
  • range= 8,000 nmi,
  • Max. fuel capacity= 64,225US gal
  • efficiency = 8 MPG (0.018 mpg per person)
  • jet fuel= 33.5 MJ/lit, 127MJ/Gal = 1016 MJ per mile, 2.18 MJ per mile per person
  • seats 467
  • 283.333 KWh per mile
  • 0.606 KHh per person per mile

    • How much energy is in a piece of paper?
    1 sheet of paper = 4.5 grams
    1 tons of dry wood= 18-22 GJ/t (7,600-9,600 Btu/lb)
    1 Ton = 1,000,000 Grams
    1.0 gigajoule (GJ) = 1,000,000,000 joules
    1 gram of wood (paper)= 1,000 joules
    1 gram of wood= 0.277777778 watt-hours
    A piece of paper has approximately 4500 jules or 1.25 watt hours; enough to power a 100 watt light bulb for around 45 seconds.
    If you compare a paper towel (4500 joules or 1.25 watt-hours) and a hand dryer (1500 watts) the we can see that the energy of one paper towel accounts for 3 seconds of hand dryer operation.
    http://bioenergy.ornl.gov/papers/misc/energy_conv.html
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    http://batteryuniversity.com/
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