Power from the Sun: Solar, Hydro and Wind - PowerPoint PPT Presentation

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Power from the Sun: Solar, Hydro and Wind


Solar Power. Most of all energy we use comes or has come from the sun. ... SB1 (Senate Bill 1) to provide rebates to equip solar power installations ... – PowerPoint PPT presentation

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Title: Power from the Sun: Solar, Hydro and Wind

Power from the SunSolar, Hydro and Wind
  • Dennis Silverman
  • U. C. Irvine
  • Physics and Astronomy

Solar Power
  • Most of all energy we use comes or has come from
    the sun.
  • Fossil fuels arise from fossil plants and animals
    converted to carbon (coal), or hydrocarbons
    (methane and petroleum).
  • We are 1/3 to 1/2 through the process of burning
    hundreds of millions of years of fossil fuel
    accumulations in two centuries.

Free Solar
  • The sun would heat the planet to 0 Fahrenheit
    without the atmosphere.
  • The sun runs the greenhouse that keeps the earth
    warmed up to an average of 58 F with the
    greenhouse gas atmosphere.
  • It evaporates the oceans to provide the rain and
    fresh water for crops and drinking water and
  • It powers the weather to provide winds.
  • It grows our crops and forests through
  • Solar energy provides our daylight and moonlight.
  • It heats our buildings in the daytime, and the
    sea and land hold heat for the night.

Pharoah Akhenaten and Queen NefertitiMonotheism
of Aten, the Sun, 1353-1336 BC Possible father of
Tutankhamen (King Tut)
Solar Manipulation
  • The next best way to use solar is to modify its
  • Reflective roofs to keep buildings cool
  • Reflective windows to keep out direct sunlight
    during the summer, and keep heat in during the
  • Windows and skylights for indoor daytime lighting

Paint Your House White? Santorini
Direct Solar Energy
  • Mediterranean climates now using rooftop or
    nearby solar water heating Greece, Israel,
    Japan. It is 80 efficient.
  • Solar clothes drying

Solar Photovoltaic Electricity
  • Silicon wafers doped to form photovoltaic cells
  • Power is free, but
  • Large wafers still thick and crystal grown as
    chips, so still expensive
  • Cost still 3 to 10 times as expensive as fossil
    fuel power
  • Efficiency only 10 to 15, so large areas needed
  • Daily and yearly average only 1/5 of maximum
    power capacity installed
  • Dont need storage if send excess power back over
    the grid
  • Storage could be in charging car batteries or in
    hydrogen fuel, or
  • Concentrate on using more energy during the
  • Silicon valley investigating thin film disk
    technology to make cheaper

Unelectrified Areas
  • Two billion people do not have electricity
  • To save on kerosene lanterns, solar cells with
    batteries and lcd lights have been developed for
    nighttime lighting
  • Also used to charge freeway phones

Californias Million Solar Roofs
  • California SB1 (Senate Bill 1) to provide rebates
    to equip solar power installations
  • Goal is 3 gigawatts solar by 2017
  • This could be 3 kw/household, at 9/watt is
  • Companies rebated per kwh generated
  • New homes must offer solar option by 2011
  • 500,000 more homes can be added to generating
    electricity into the power network
  • 2.8 billion CA cost, 30 Federal rebate, up to
    18 billion total cost, but for less average
    electricity than a nuclear plant at 2-3 billion.
  • Could only nearly pay if it brings down costs
    through economies of scale,
  • or if it leads to technological breakthrough
    through research and competition
  • Only 100 million for solar water heating

U. S. Solar Resources
U. S. Tracking Mirror Solar
Solar Trough Mirrors
  • Suitable For Large Systems
  • Grid-connected Power
  • 30-200 MW size
  • Heats mineral oil to hundreds of degrees
  • Then vaporizes a fluid to drive a turbine

Dish with Sterling Engine
  • Modular
  • Remote Applications
  • Demonstration Installations
  • High Efficiency
  • Conventional Construction
  • Heat expands gas and drives piston

Solar Tea? Tibet, Dreprung Monastery
Solar Tower
  • Suitable For Large Systems
  • Grid-connected Power
  • 30-200 MW size
  • Potentially Lower Cost
  • Potentially Efficient Thermal Storage
  • Molten Salt heated, averages out solar input
  • Can store heat overnight

Cost Of Energy(Max Lechtman)
  • Trough Dish/Engine Tower
  • 2000 11.8 17.9 13.6
  • 2010 7.6 6.1 5.2
  • 2020 7.2 5.5 4.2
  • 2030 6.8 5.2 4.2
  • Cents/kWh in 1997

  • Of the renewable energy sources that generate
    electricity, hydropower is the most often used.
    It accounted for 7 percent of total U.S.
    electricity generation and 75 percent of
    generation from renewables in 2004
  • Over one-half of the total U.S. hydroelectric
    capacity for electricity generation is
    concentrated in three States (Washington,
    California and Oregon) with approximately 27
    percent in Washington, the location of the
    Nations largest hydroelectric facility the
    Grand Coulee Dam

How Hydropower Works
(No Transcript)
World-wide, about 20 of all electricity is
generated by hydropower.
Glen Canyon Dam and Power Station
Aswan Dam on the Nile River
Wind Power - Mykonos
Clipper Ship
World Wind Capacity. Total now 74 Gigawatts
worldwide, with 65 in Europe. Market growing at
32 a year. 3.3 of European electricity now
from wind. 1 of U.S. electricity.
Wind Generation Physics
  • Power proportional to the cube of the wind
  • (v² from Bernoulli pressure for force on
    wingshaped propeller, times a distance per second
    of rotating propeller, which is proportional to
  • Most of energy from small bursts.
  • ½ of energy comes in 15 of the time.
  • Average capacity factor is 35 of the maximum.
  • Wind turbines best spaced 3-5 times the rotor
    diameter perpendicular to the wind, and 5-10
    times the diameter parallel to the wind.

Virginias Switzerland Wind Power Proposal
  • 39 towers of 400 feet height
  • 2 million per tower at 1 megawatt
  • So about a 40 megawatt peak project
  • Enough power for 15,000 homes x
  • 12,000 kwh/yr / 9,000 hours/year
  • 20 million watts average
  • Implies a 50 duty cycle
  • To compare to a 1 gigawatt nuclear plant, would
    require 50 such projects, or about 2,000 wind
    towers and 2 billion.

England, Germany, Netherlands10 Gigawatt
Foundation Project
  • Proposal for 2,000 wind turbines of 5 megawatts
    each to make 10 gigawatts
  • Could power more than 8 million homes
  • Would cover 3,000 square kilometers
  • In the southern North Sea

Here Comes The Sun (by George Harrison)
  • All renewable energy is local Adapt to locally
    available sources of renewable energy
  • Energy conservation is still the cheapest form of
    making energy available
  • In California, solar water heating is the next
    cheapest source of energy
  • Hydro should be maintained
  • Solar arrays are efficient and should be
  • Wind power is about the cost of nuclear. Have to
    find the right location. Siting a problem with
    views, noise, birds.
  • Nuclear power is omitted from renewable, but
    should be included as it also is non-polluting
    for greenhouse gases.
  • Solar photovoltaic needs more research and
    improvement, and is currently a wasteful
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