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EnergyEnergy
The ultimate addiction of civilisationThe ultimate addiction of civilisation
Energy consumptionEnergy consumption
90% of energy consumed in developed 90% of energy consumed in developed countries is from fossil fuelscountries is from fossil fuels
10% are from hydropower, nuclear, solar, 10% are from hydropower, nuclear, solar, windwind
Renewable sources are Renewable sources are alternative sourcesalternative sources
Energy efficiency: 1Energy efficiency: 1stst law law
First law efficiencyFirst law efficiency – amount of E without – amount of E without consideration of its quality. Expressed as a %. consideration of its quality. Expressed as a %.
It is a ratio of the actual amount of energy It is a ratio of the actual amount of energy delivered where it is needed to the amount of delivered where it is needed to the amount of energy supplied to meet that needenergy supplied to meet that need
A fluorescent bulb converts 1/5 of electrical A fluorescent bulb converts 1/5 of electrical energy into light. Thus its 1energy into light. Thus its 1stst law efficiency is law efficiency is 20%20%
Energy efficiency: 2Energy efficiency: 2ndnd law law
Second law efficiencySecond law efficiency: the ratio of : the ratio of minimum available work needed to minimum available work needed to perform a particular task to the actual perform a particular task to the actual work needed to perform that taskwork needed to perform that task
A car has a 1A car has a 1stst law efficiency of 20%. law efficiency of 20%. 80% is unusable energy.80% is unusable energy.
Out of that 20% 1Out of that 20% 1stst law efficiency, 10% is law efficiency, 10% is 22ndnd law efficiency law efficiency
Energy efficiencyEnergy efficiency
11stst law efficiency may be misleading. A high law efficiency may be misleading. A high efficiency may mean no more energy saving efficiency may mean no more energy saving improvements may be done.improvements may be done.
22ndnd law efficiency takes note of work. That is law efficiency takes note of work. That is energy applied.energy applied.
A car has a low 2A car has a low 2ndnd law efficiency since high law efficiency since high quality gasoline wastes much heat that quality gasoline wastes much heat that otherwise may used to do additional work.otherwise may used to do additional work.
The solution is to use a fuel that doesn’t waste The solution is to use a fuel that doesn’t waste much heat and do more useful work.much heat and do more useful work.
REGULAR COMBUSTION REGULAR COMBUSTION ENGINEENGINE
A lot of the energy is wasted in the heat A lot of the energy is wasted in the heat of the exhaust as well as in the radiator.of the exhaust as well as in the radiator.
Pollution (NOPollution (NOxx , SO , SOxx VOC and other) VOC and other)
Has a very low efficiency, about Has a very low efficiency, about
20-25% .*20-25% .*
* Physics Today. April 2002
What is energy What is energy conservation?conservation?
This refers simply to This refers simply to getting by with more getting by with more work with less demandwork with less demand for energy for energy
This means improving 2This means improving 2ndnd law efficiency law efficiency Cogeneration: using waste heat to do Cogeneration: using waste heat to do
supplementary worksupplementary work Example: Have you heard of the guy who Example: Have you heard of the guy who
barbecues while drivingbarbecues while driving his V8 engine car? his V8 engine car?
Fossil fuelsFossil fuels
95% of Philippine energy needs95% of Philippine energy needs Relatively cheap as of now.Relatively cheap as of now. Petroleum is also made into plastics and other Petroleum is also made into plastics and other
synthetic materials including fertilizerssynthetic materials including fertilizers Only a few countries have enough supplies. Only a few countries have enough supplies.
E.g. Saudi Arabia, IraqE.g. Saudi Arabia, Iraq Some of the countries have political problemsSome of the countries have political problems
Where is the oil?Where is the oil?
Why is the price of oil Why is the price of oil going up?going up?
Economic developmentEconomic development China, India and Southeast Asian China, India and Southeast Asian
countries have a rising middle class who countries have a rising middle class who want carswant cars
Political troubles: Iraq, Saudi ArabiaPolitical troubles: Iraq, Saudi Arabia USA- preference for SUVsUSA- preference for SUVs New oilfields require more investmentsNew oilfields require more investments
Top 5 consumers of oilTop 5 consumers of oil
1.1. United StatesUnited States
2.2. ChinaChina
3.3. RussiaRussia
4.4. JapanJapan
5.5. United States’ AutomobilesUnited States’ Automobiles
Two major choicesTwo major choices
Change your car for Change your car for cars with new cars with new propulsion technologiespropulsion technologies (hybrids, fuel (hybrids, fuel cells or electric)cells or electric)
Change from gasoline or diesel to new Change from gasoline or diesel to new fuels but these fuels but these new fuels can run your new fuels can run your car without engine modification (car without engine modification (biodieselbiodiesel))..
Easier to Change the Car Easier to Change the Car Than to Change the Than to Change the Person!!Person!!
Sport Utility Vehicles are a Status SymbolSport Utility Vehicles are a Status Symbol Only 10-30% of people who own SUVs actually use Only 10-30% of people who own SUVs actually use
them for off-road activitiesthem for off-road activities 38% of the cars on the road are SUVs38% of the cars on the road are SUVs
With Hybrid technology, people can keep their With Hybrid technology, people can keep their “big” cars while using less fuel.“big” cars while using less fuel. Ford Escape, 2004Ford Escape, 2004 Dodge Durango SUV, uncertain release dateDodge Durango SUV, uncertain release date
How Hybrids WorkHow Hybrids Work
Electric portion of the motor gets power Electric portion of the motor gets power from nickel-metal hydride battery (next to from nickel-metal hydride battery (next to fuel tank)fuel tank)
NO PLUGGING IN NEEDED! (battery NO PLUGGING IN NEEDED! (battery maintained by regenerative braking- maintained by regenerative braking- kinetic energy captured by forward kinetic energy captured by forward momentum)momentum)
Gasoline engine made from plastic Gasoline engine made from plastic materialsmaterials
Other car technologiesOther car technologies
Electric carsElectric cars Hybrid cars- gas and electricHybrid cars- gas and electric Fuel cell cars Fuel cell cars
Why go alternative?Why go alternative?
Mileage- a hybrid car can go 20 km or Mileage- a hybrid car can go 20 km or more to a litermore to a liter
More environment friendlyMore environment friendly Celebrity appeal: Leo DiCaprio drives 4 Celebrity appeal: Leo DiCaprio drives 4
hybrid cars. Russel Crowe drives one.hybrid cars. Russel Crowe drives one.
How It Works How It Works
Two or more sources of power combinedTwo or more sources of power combined Ex:Ex:
Mo-pedMo-ped TrainsTrains BusesBuses Mining trucksMining trucks Submarines Submarines
A BATTERY-POWERED A BATTERY-POWERED CARCAR
Battery efficiency: ~90%Battery efficiency: ~90%Motor efficiency ~80%Motor efficiency ~80%TOTAL: TOTAL: 72%72%No Pollution No Pollution ??????Remember that the power had to be Remember that the power had to be
generated somewhere else, most likely a generated somewhere else, most likely a conventional coal plant! ~40%.conventional coal plant! ~40%.**
Real Efficiency ~29%Real Efficiency ~29%
* Berinstein, Paula. Alternative Energy: Facts, Statistics, and Issues. Westport, CT, Oryxpress 2001
Comparing the Battery and Comparing the Battery and Fuel Cell in automobileFuel Cell in automobile
Fuel cell slightly more efficient and Fuel cell slightly more efficient and without the conventional pollutionwithout the conventional pollution
Fuel cell design offers convenient Fuel cell design offers convenient “recharge” at a gas station“recharge” at a gas station
Fuel cell automobiles are still much more Fuel cell automobiles are still much more expensive ($80,000expensive ($80,000
80mpg/52mpg (Toyota Prius-hybrid)80mpg/52mpg (Toyota Prius-hybrid)
~300
~0
~0
~0
~6-7,000
Can perform similar analysis for a large scale power generation
ComponentsComponents
Gas engineGas engine Fuel tankFuel tank Electric motorElectric motor GeneratorGenerator BatteriesBatteries Transmission Transmission
Electric Motor Electric Motor ComponentsComponents
Armature or rotorArmature or rotor Thin wire coiled around two or more polesThin wire coiled around two or more poles
CommutatorCommutator Plate pair attached to axlePlate pair attached to axle
BrushesBrushes Provides “flipping” action with the commutator Provides “flipping” action with the commutator
AxleAxle Field magnetField magnet DC power supplyDC power supply
PolesPoles
Car motors usually have 3 poles…Car motors usually have 3 poles… Better dynamics in the car (magnet cannot Better dynamics in the car (magnet cannot
get “stuck” b/w the poles)get “stuck” b/w the poles) Avoids wasting energy and wasting the Avoids wasting energy and wasting the
batterybattery
GeneratorGenerator
Similar to electric motor, but only Similar to electric motor, but only produces electrical powerproduces electrical power
Used in series hybridsUsed in series hybrids Electric motor acts like a generator when Electric motor acts like a generator when
it slows car down to charge the batteriesit slows car down to charge the batteries
Batteries Batteries
Higher voltagesHigher voltages serial serial Higher currentsHigher currents parallel parallel Energy storage device for electric motorEnergy storage device for electric motor Electric motor: puts energy into batteries Electric motor: puts energy into batteries
and draws from themand draws from them Gives that extra “help”Gives that extra “help”
The upper arrangement is called a parallel arrangement. If you assume that each cell produces 1.5 volts, then four batteries in parallel will also produce 1.5 volts, but the current supplied will be four times that of a single cell. The lower arrangement is called a serial arrangement. The four voltages add together to produce 6 volts.
Types of HybridsTypes of Hybrids
Parallel hybridParallel hybrid Fuel tank provides gasoline to engineFuel tank provides gasoline to engine Batteries supply power to electric motorBatteries supply power to electric motor Engine and electric motor work together to Engine and electric motor work together to
turn transmission simultaneouslyturn transmission simultaneously Transmission turns the wheelsTransmission turns the wheels
Parallel HybridParallel Hybrid
Fuel tank and gas engine connect to Fuel tank and gas engine connect to transmissiontransmission
Batteries and electric motor connect to Batteries and electric motor connect to transmission independently transmission independently
Thus, electric motor and gas engine Thus, electric motor and gas engine propel autopropel auto
Civic Hybrid StatsCivic Hybrid Stats
48 mpg city/47 mpg highway (ULEV)48 mpg city/47 mpg highway (ULEV) Actual: 43 mpg city / 52 mpg highway Actual: 43 mpg city / 52 mpg highway City fuel efficiency decreases in winter when temps City fuel efficiency decreases in winter when temps
are below freezing; closer to 35 mpg in city; highway are below freezing; closer to 35 mpg in city; highway stays the samestays the same
47 mpg city/48 mpg highway (SULEV)47 mpg city/48 mpg highway (SULEV) 1/03: SULEV marketed in California1/03: SULEV marketed in California
650 miles per tank of gasoline650 miles per tank of gasoline IMA technology; 1.3 L VTEC 4-cylinder engineIMA technology; 1.3 L VTEC 4-cylinder engine 10 year battery life10 year battery life
Toyota PriusToyota Prius
Parallel hybridParallel hybrid Electric motor starts the carElectric motor starts the car Power Split DevicePower Split Device
Series hybridSeries hybrid
Only Available in a Continuously Variable Only Available in a Continuously Variable Transmission (CVT)Transmission (CVT)
How to make the most of How to make the most of your hybridyour hybrid
Don’t speedDon’t speed Keep speed constantKeep speed constant Don’t stop abruptlyDon’t stop abruptly Manual transmissions: let the Manual transmissions: let the
regenerative braking work before putting regenerative braking work before putting in the clutchin the clutch
WHAT IS A FUEL CELLWHAT IS A FUEL CELL
Reversed Electrolysis Reversed Electrolysis DeviceDevice
Pt coated electrodesPt coated electrodes
Use air as a source of Use air as a source of OO22
How Does it WorkHow Does it Work
Electrolyte- proton-Electrolyte- proton-exchange-membrane exchange-membrane (PEM), Phosphoric Acid(PEM), Phosphoric Acid
Combines Fuel and Combines Fuel and OxygenOxygen
Produces HProduces H220 (l), heat, 0 (l), heat, COCO22
www.howstuffworks.com
Still a little fuzzy? DOE’s website:http://fossil.energy.gov/coal_power/fuelcells/fuelcells_howitworks.shtml
ADVANTAGES OF FUEL ADVANTAGES OF FUEL CELLSCELLS EFFICIENCYEFFICIENCY
Fuel cells can convert as much as 80% of the Fuel cells can convert as much as 80% of the energy stored in the fuel energy stored in the fuel **
QUIETQUIET
NO MOVING PARTSNO MOVING PARTS
EXTRA HEAT CAN BE USEDEXTRA HEAT CAN BE USED
* Berinstein, Paula. Alternative Energy: Facts, Statistics, and Issues. Westport, CT, Oryxpress 2001
Graph Courtesy of Mercedes-Benz
MORE ADVANTAGESMORE ADVANTAGES
Low Pollution- Fuel cells produce only Low Pollution- Fuel cells produce only water and COwater and CO22 depending upon the fuel depending upon the fuel usedused
Low Maintenance/Operating costLow Maintenance/Operating cost
Can use conventional fuels - gasoline, Can use conventional fuels - gasoline, methane, propanemethane, propane
Small or large scale usesSmall or large scale uses
DISADVANTAGESDISADVANTAGES
Still produce COStill produce CO22 although with more although with more usable energy.usable energy.
Expensive: (Pt) It costs about $40,000 to Expensive: (Pt) It costs about $40,000 to make a fuel cell system for a car.make a fuel cell system for a car.** (Power plant estimated costs 1999: $800-1200/kWh (The first one in (Power plant estimated costs 1999: $800-1200/kWh (The first one in
Austin cost about $4000/kW)Austin cost about $4000/kW)****))
Hydrogen/Reformer ProblemHydrogen/Reformer ProblemClean FuelClean Fuel
* Berinstein, Paula. Alternative Energy: Facts, Statistics, and Issues. Westport, CT, Oryxpress 2001** Daily Texan 17.7. 2002
FUEL CELL IN FUEL CELL IN AUTOMOBILESAUTOMOBILES
Fuel Cell efficiency~40% (depends on fuel)-Fuel Cell efficiency~40% (depends on fuel)-recall reformer, up to 80% if heat regeneratedrecall reformer, up to 80% if heat regenerated
Motor efficiency ~80%Motor efficiency ~80%
Can be combined with recharging while brakingCan be combined with recharging while braking
Overall Efficiency: ~32%Overall Efficiency: ~32%
What about other What about other alternatives?alternatives?
Solar energy- perfect for heating but has Solar energy- perfect for heating but has low 1low 1stst law efficiency (electricity) law efficiency (electricity)
Biofuels –low efficiency: renewableBiofuels –low efficiency: renewable Nuclear – efficient but has waste disposal Nuclear – efficient but has waste disposal
problemproblem Garbage – low efficiencyGarbage – low efficiency
The major disadvantage The major disadvantage of alternativesof alternatives
EXPENSIVE!!! A hybrid car is double or EXPENSIVE!!! A hybrid car is double or triple the price of a standard cartriple the price of a standard car
That’s why only the likes of Russel That’s why only the likes of Russel Crowe and Leo Dicaprio can afford one!Crowe and Leo Dicaprio can afford one!
However some alternatives are cheapHowever some alternatives are cheap.. A pair of walking shoes is much cheaper A pair of walking shoes is much cheaper
than an SUV.than an SUV. And so is a bicycle!And so is a bicycle!
How can we conserve How can we conserve energy?energy?
Increase your 2Increase your 2ndnd law efficiency: walk (walking law efficiency: walk (walking is good for the heart!)is good for the heart!)
Properly maintain your carProperly maintain your car Take public transport. This increases 2Take public transport. This increases 2ndnd law law
efficiencyefficiency Turn off the lights when not in use. Use natural Turn off the lights when not in use. Use natural
lightinglighting Use airconditioning when absolutely needed.Use airconditioning when absolutely needed.
What kind of energy What kind of energy efficiency are you efficiency are you improving?improving?
I jog to my next class in Palma Hall.I jog to my next class in Palma Hall. I car poolI car pool Instead of taking Ikot or Toki, I bike to my Instead of taking Ikot or Toki, I bike to my
next classnext class I use low wattage fluorescent bulbsI use low wattage fluorescent bulbs I use a solar powered calculatorI use a solar powered calculator
More on alternative More on alternative energy sourcesenergy sources
Alternative energyAlternative energy BiodieselBiodiesel