p owered by the sun: r enewable e nergy m yths, d istortions and r eality
TRANSCRIPT
OUTLINES
History
Traditional Sources of Energy
Current and Projected Energy Production
Renewable Energy Resources
Discussion and Evaluation
Pearl Street station 1882HISTORY
A sketch of the exterior of the Pearl Street station. Courtesy: Photographic Services of the Consolidated Edison Company of New York, Inc.
First commercial station 1882- Built by Thomas Edison- Operated on DC current- Started with 59 customers!- Cost: 24¢/KWh- Operated on coal- Operated at night only
until 1889
THE FIRST COMMERCIAL STATION
Each “jumbo dynamo” produced 100 KW power enough to power 1200 light bulbs
6 dynamos were installed in the station to light up 1 square mile in New York City.
Edison's Jumbo dynamo. Courtesy: National Park Service, Edison National Historic Site.
27-ton “Jumbo” dynamo
POWER GENERATION
(a) A 2-pole machine has one N and one S pole on the rotor and on the stator. (b) A 4-pole machine has 4 poles on the rotor and 4 on the stator.
Renewable and efficient electric power systems / Gilbert M. Masters, 2004, John Wiley & Sons, Inc.,
FOSSIL FUEL, STEAM-ELECTRIC POWER
PLANT
Renewable and efficient electric power systems / Gilbert M. Masters, 2004 by John Wiley & Sons, Inc.,
Traditi
onal
Power s
ources
COAL POWER
Mass flows to generate 1 kWh of electricity in a 33.3% efficient, coal-firedpower plant burning bituminous coal
FOSSIL FUEL-FIRED POWER PLANTS
Burn coal heat water steam turn the turbine
500 plants currently in operation
Three types: Pulverized Coal plants: – burn coal only - most polluting, ~ 37-
38% efficiency Fluidized Bed plant: – burn coal, biomass, waste, tires, other
fuel. 40 to 50% efficiency. Integrated Gasification Combined Cycle (IGCC) plants: burn
syngas (synthetic gas, extracted from coal and other organic materials). 60% efficiency. more expensive.
There is no such thing as clean coal!
ENVIRONMENTAL COST
For each megawatt-hour from a coal plant:
2,249 lbs of carbon dioxide,
13 lbs of sulfur dioxide, and
6 lbs of nitrogen oxide
Traces of mercury (Hg)
> 140 other chemicals classified as “hazardous air pollutants” by the EPA
STOP: GREENHOUSE GASES ARE GOOD!
• The Earth average temperature is 15o while the Moon’s average temperature is -18o
• Both objects are within similar distance from the sun
• The question is how much is released?
• Are we tipping the balance
NUCLEAR POWER
Two types:
1. The Boiling Water Reactor (BWR)
2. The Pressurized Water Reactor (PWR)
Traditi
onal
Power s
ources
THE BOILING WATER REACTOR (BWR)
The Boiling Water Reactor (BWR)
BWRs actually boil the water. Water is converted to steam, and then recycled back into water by a part called the condenser, to be used again in the heat process.
Pressure =70 atmosphere
H2O boiling T= 285 oC
Operating Efficiency = 32%
Traditi
onal
Power s
ources
The Pressurized Water Reactor (PWR)Pressure =160 atmosphere
H2O boiling T= 315 oC
THE PRESSURIZED WATER REACTOR
(PWR)
NUCLEAR PLANTS
Positives
CO2 emissions are minimal
The power produced by the world's nuclear plants would normally produce 2 billon metric tons of CO2 per year if they depended on fossil fuels
Negatives
Annually generates 20 metric tons of used high-level radioactive nuclear waste. Over 2,000 metric tons produced yearly world wide.
The waste emits radiation and heat, meaning that it will eventually corrode any container and can prove lethal to nearby life forms
It takes tens of thousands of years for the waste to reach safe radioactive levels
The waste has to be maintained, monitored and guarded to prevent the materials from falling into the wrong hands. All of these services and added materials cost money -- on top of the high costs required to build a plant.
U-235 halflife = 700 million years U-238 halflife = 4.5 billion years
NUCLEAR PLANTS
Investment $2.5 to 4 Billion
Investment recovery time: 25 to 40 years
~ One decade to plan
Federal new nuclear generation tax credit: $1 billion per first Gegawatt of power
WORLD TOTAL ELECTRICITY NET GENERATION
(TERAWATTHOURS)
Elect
rical
Gen
erat
ion
Energy Information Administration (EIA)-US Government
WORLD GENERATION PERCENTAGE
Elect
rical
Gen
erat
ion
Energy Information Administration (EIA)-US Government
THE ROLE OF RENEWABLE ENERGY CONSUMPTION IN THE NATION’S ENERGY
SUPPLY, 2007
Total
Energy
Consum
ption
Energy Information Administration (EIA)-US Government
Marland, G., T.A. Boden, and R. J. Andres. 2003. "Global, Regional, and National CO2 Emissions." In Trends: A Compendium of Data on Global Change. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., U.S.A. http://cdiac.esd.ornl.gov/trends/emis/tre_glob.htm]
Note the start of coal contributionand petroleum contribution (cars)
Carbon Dioxide Information Analysis Center (CDIAC)
Note the change in Europe’s contributionMostly due environmental policies
OBSESSION WITH FOSSIL
CNN News Feb. 1, 2009:
Exxon shatters profit records
Oil giant makes corporate history by booking $11.7 billion in quarterly profit; earns $1,300 a second in 2007.
This is during recession!!!
Sources:
1. Hydroelectric
2. Geothermal
3. Ocean/Tides
4. Wind
5. Biomass
6. Solar
RENEWABLE SOURCES
COMPARISON
Renewable Traditional, fossil based
Examples Wind, solar, tidal, hydro, geothermal Coal, biomass, oil, gas, radioactive ore
Source Natural local environment Concentrated stock
Normal state A current or flow of energy Static store of energy, Capital
Initial average intensity
Low intensity, dispersed: ≤300Wm−2 Released at ≥100kWm−2
Lifetime of supply Infinite Finite
Cost at source Free Increasingly expensive
Location for use Site- and society-specific General and invariant use
COMPARISONRenewable Traditional, fossil based
Scale Small and moderate, self-sufficient
Large scale often economic, depends on outside input
Pollution andenvironmental damage
Usually little or no environmental harm,
Large hydro reservoirs disruptive
Compatible with natural ecology
Environmental pollution intrinsic and common, especially of air and water
Soil erosion from excessive biofuel usePermanent damage common from mining and radioactive
elements entering water table.
Deforestation and ecological sterilization from excessive air pollution
Climate change emissions
HYDROELECTRICOLDEST RENEWABLE
SOURCE No fuel combustion
Minimal air pollution compared to fossil fuel plants
limited thermal pollution compared with nuclear plants
Like other energy sources, the use of water for generation has limitations, including environmental impacts caused by damming rivers and streams, which affects the habitats of the local plant, fish, and animal life.
HYDROELECTRIC
Photo courtesy U.S. Bureau of ReclamationThe giant generators at Hoover Dam produce more than 2,000 megawatts.
http://ga.water.usgs.gov/edu/hyhowworks.html
Photo courtesy U.S. Bureau of ReclamationThe shaft that connects the turbine and generator
HYDROELECTRIC FUN
Photo courtesy U.S. Patent and Trademark OfficeImage from patent No. 6,239,501:
Footwear with hydroelectric generator assembly
GEOTHERMAL
- The center of the earth is approximately 4000 degrees Celsius
- Geothermal energy is contained in underground reservoirs of steam, hot water, and hot dry rocks
~10000 ft
BIOMASS
Three Main Sources:
Wood
- Direct use of wood
- Wood waste:
Waste:
- Municipal solid waste,
- recycling, composting, landfilling, and waste-to-energy via incineration
- manufacturing waste
- landfill gas
Alcohol fuels Mostly from Corn
SOLARTHERMAL
Solar thermal:
- from heating swimming pools to creating steam for electricity generation
Stirling Energy Systems, Inc. (SES)/Boeing, 25 kW Dish Stirling system at sunset
Heating only
SOLAR THERMAL
Ausra claims that a land footprint of 9,600 square miles, about 1% of US deserts is needed to power the whole USA.
HOW MUCH AREA FOR THERMAL SOLAR
how much land would be needed to power the world, Europe or Germany with solar-thermal power Spiegel Online
RENEWABLE SOURCES
Source Theoretical limit
Feasible
Hydroelectric 4.6 TW 1.5 TWGeothermal 11.6 TW (land) 200 oC @ 10Km- cost $$$
Ocean/Tides 2.7 TWWind 300 TW 2 TWBiomass 20 TW Require 31% of the planet’s land
Solar 1.2x105 TW 600 TW 50 to 1500 TW depending on land fraction, 10% efficiency,
Needs by 2010: ~ 17 TW
WHERE TO SPEND YOUR TAXES
Federal new nuclear generation tax credit: $1 billion per first Gegawatt of power incentives to 3 nuclear reactors
Capacity 3 – 4.5 GW Payback period 25-40 yrs
OR
Renewable energy (tax credit) 3 GW of clean solar power Payback period 5-10 yrs
ETHICAL ISSUES
Is it Ok to litter in your neighborhood, smoke in a classroom?
Why then litter the whole globe?
CRITICAL THINKING OF SCORCH-EARTH
GEEKS! Communists and socialists ideas
A: Aren’t we making communists look good? When did communists were green? They destroyed the environment of every country they ruled.
CRITICAL THINKING OF SCORCH-EARTH
GEEKS! Efficiency is not high!
How much are we paying for the sun light to ask about efficiency?
Commercial single crystalline solar cell > 20%
Poly crystalline cells > 15%
CRITICAL THINKING OF SCORCH-EARTH
GEEKS! Solar farms require large areas
A: It might be true that actual foot print of a coal or a nuclear plant is small, but the waste backyard is much larger, from poisoning whole lakes to atmospheric impact. The large area has a positive impact. It utilizes deserts and wastelands.
Example of lands needed for 1 MW solar plant:- 1 MWp panels produces ~ 5.5 MWh each day (North
Carolina)- Efficiency: 13.4%, Area:7992 m2 = 1.975 Acre (based on commercial panels)- Average house consume ~10 KWh/day 550 houses- There are 271,790 houses in charlotte* (2.4 household size)- Power plant area for charlotte: 495*1.975= 973 Acre.- 1 GWp plant 1975 Acres = 7.99 km2 = 3 miles2
Not bad!!*http://realestate.aol.com/Charlotte-NC-real-estate
HOW MUCH AREA
the world's current demand (assuming efficiency of 8%).
- current solar panels have an efficiency higher than 16%
The colors in the map show the local solar irradiance averaged over three years from 1991 to 1993 (24 hours a day) taking into account the cloud coverage available from weather satellites
HOW MUCH AREA
Location / Desert Desert Size km2 [1]
Irradiation W m-2
Area required km2
Africa, Sahara 9,064,960 260 144,231Australia, Great Sandy 388,500 265 141,509China, Takla Makan 271,950 210 178,571Middle-East, Arabian 2,589,910 270 138,889South America, Atacama 139,860 275 136,364U.S.A., Great Basin 492,100 220 170,455
References
1) Map of World Deserts. http://www.mapsofworld.com/world-desert-map.htm
CRITICAL THINKING OF SCORCH-EARTH
GEEKS! You can not drive a car with it!
Is this is an energy criteria? Do we drive cars with nuclear power?
The “green car” of today’s technology is driven by electricity.
Solar power can charge the battery while parking during work
Google Headquarter –CaliforniaSolar Powered: 50 megawatts of electricity by 2012
car port with solar panels as a roof for charging up plug-in hybrids.
Google officials: investment will pay for itself in seven and a half years
Radiation power is too low, only 200 W/m2 What can you do with 200 W/m2 ?
A: misconception; ~ 1 KWh/m2 for 5 to 6 hrs 5 to 6 KWh/m2.day an effective average of ~ 210 to 250 W/m2 at any time
CRITICAL THINKING OF SCORCH-EARTH
GEEKS!
YES, WE CAN HAVE ZERO EMISSION
Source Theoretical limit Feasible
Hydroelectric 4.6 TW 1.5 TW
Geothermal 11.6 TW (land) 200 oC @ 10Km- cost $$$
Ocean/Tides 2.7 TW
Wind 300 TW 2 TW
Biomass 20 TW Require 31% of the planet’s land
Solar 1.2x105 TW 600 TW 50 to 1500 TW depending on land fraction, 10% efficiency,
Needs by 2010: ~ 17 TW
From: Nathan Lewis, Cal tech
Solar PV prices
6% Compound annual growth
4% Compound annual growth
Grid electricity prices
Convergence zone
Projected conversion time frame
Price range
MARKET OVERVIEW: PRICE CONVERGENCE
Price convergence between the Grid and solar energy is expected between ~ 2011 and 2016
SUMMARY
Nature provide ample of resources to use
Our energy need is growing
Solar in 1 hour > Fossil in one year, but we spend in 1 hour $$$ gasoline > solar R&D in 6 years
The case for CO2 reduction is clear
Incentives must be employed now in order to achieve CO2 reduction by the middle of the century
Is failure an option?
Approximate location of Voyager 1 while taking the photograph
Sun
PALE BLUE DOT!
From: NASA and Wikipedia
Light from Earth travels 5.5 hrs for the signal to reach Voyager 1.
Earth seen from 6.4 billion kilometers away, Earth is a dot obscured in a beam of scattered sunlight. Earth was a crescent only 0.12 pixel in size!
Mercury, Venus, Earth, and Mars orbits are small to show
Earth
Carl Sagan on Commencement speech on May 11, 1996:Consider again that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every …… every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar," every "supreme leader," every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam .…..
Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner, how frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds.
Our posturing, our imagined self-importance, the delusion that we have some privileged position in the Universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves.