Transcript Willow Bioenergy Crops: Locally Grown Renewable Energy

Energy Alternatives
CDAE-06
Renewable Intro
Gary Flomenhoft
http://www.uvm.edu/~gflomenh/CDAE06/
WORLD
ENERGY
Fossil Fuel: 75.9%
Nuclear: 5.7%
Renewable: 18.4%
Net Energy
DIRECT-GAIN
• Large south facing windows
that let in the sunlight.
• Thermal mass is used to
absorb the radiation.
• At night the absorbed heat is
radiated back into the living
space.
Collectors-Flat Plate
Collectors-Evacuated tube
Installation
Solar-thermal power plants-tower
MEADI BOILER
Solar trough-Barstow
Photoelectric Effect
A picture of an typical silicon PV cell
Now a short video:
http://www.eere.energy.gov/solar/multimedia.html
CZOCHRALSKI PROCESS
• This is the process of
creating an ingot.
• A small single silicon rod
(seed) is placed in an inert
gas at high temps.
• When the seed is rotated
up and out silicon adheres
to it to form an ingot.
CELLS -> MODULES
• Wafers 5 inches square and .012 inches thick are sliced from the ingot.
• They are then processed into cells and soldered together to achieve the desired
voltage.
• Cells arrayed in series are called modules.
MANUFACTURERS
• Sharp Electronics
Corporation
• Sanyo
• bp Solar
• Shell
• Sunwise
• Uni-Solar
• AstroPower
POLYCRYSTALLINE SOLAR
PANELS
“Energy of the Future”
Thin Film History
• Developed in 1980
• Applied to calculators, watches and
other portable low-watt appliances
• Expanded to larger appliances as
efficiency rate increased
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Cost by Brand
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
• Unisolar 21 watt= $153.00
• Shell 20 watt= $198.00
• Isofoton 165 watt= $650.00
-research shows that on average thin cell costs $5
per watt
CDAE 170
Solar Building Strategies
PV system design
Dec. 1, 2003
Gary Flomenhoft
BSME, MAPP, CEE
Research Associate
Gund Institute, SNR
Biomass: In Vermont
VT Energy Consumption Sources
• Nuclear 36%
• System 14%
• Hydro Quebec 35%
• Oil 2%
• Gas 1%
• Other Renewable 5%
Since 1984, Vermont has met all increase
• Small Hydro 7%
in energy demands(a total of 125 Mw) by
renewable in-state sources:
EPA Landfill
Incentive Program
http://www.epa.gov/lmop/
-40 Mw Small Hydro
-73 Mw McNeil/Rygate
(Biomass Plants)
-6 Mw Searsburg Wind Farm
Kinds of Biomasstraditional
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Trees- Wood has been used as a source of energy throughout human history and today the
most commonly used form or biomass. Today there are still many people in third world
countries using it to provide heat and energy. There are also ‘purpose grown’ tree farms
which are specifically grown to produce wood for energy in larger developed countries.
More traditional Biomass types
• Straw is used similarly too
wood, it is burned and used to
make heat and energy
• Animal Dung- Poop is often
used as a source of heat and
energy
More non-traditional Biomass
• Landfill gas- The gas
emitted from landfills is
very rich in methane, it is
collected and used to
generate power in small
scale power plants.
Gasohol
• Ethanol Alcohol
generated by fermenting
sugar cane or corn is
combined with gas and
used to power
cars…mmm…tasty
gasohol.
Biodiesel
Biodiesel is made from:
• vegetable oil
• alcohol (20-30%)
• sodium/potassium
hydroxide (2-3%)
Total: 6740MW in 2004
Installed wind energy generating capacity now
totals 6,374 MW, and is expected to generate
about 16.7 billion kWh of electricity in 2004.
However, that is still less than 1% of U.S.
electricity generation. By contrast, the total
amount of electricity that could potentially be
generated from wind in the United States has
been estimated at 10,777 billion kWh
annually—three times the electricity
generated in the U.S. today.
Pros of the Project
•Replaces 113 million tons of oil per
year
• “Zero-emissions”
•Boost to Cape Cod’s economy
-600-1,000 new jobs for Cape
Codders
•Does not require land
•May help with navigation and rescue
The Alliance’s Simulation from Cotuit
HYDRO
• 1/10 of electricity, US.
• 20% World electricity
Large Hydro-systems
• Defined as greater than 30
megawatts by Department of
Energy
• Hoover dam- (1300 MW)
• Grand Coulee (6480 MW
• Largest:
• Venezuela (10 GW)
• Itaipu-Brazil (12.6 GW
• China- 18.6 GW (2009)
Three Gorges Dam
• Over one mile long
• 575 feet tall.
• 25-75 billion dollars.
• 20 years of construction
• 18,600 MW
• Completion in 2009
Small Hydro-systems
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DOE 100kw – 30mw
Industries, towns
Thailand (9mw)
Winooski (5MW)
Essex (7MW)
Micro-hydro system
• DOE 0-100 kw
• Farm, home, village
• Increasing in #’s
Today
Impoundment Type or “Run-of-the-River
w/o impoundment
Diversion Type
Diversion (Brazil)
Turbines: Reaction or Impulse
Turbines: Reaction or Impulse
Reaction-type Turbine-Propellor
• Low-head situations (high
flow/ low PSI)
Reaction-type Turbine-Kaplan
• Low-head situations (high flow/ low
PSI)
Inside of Micro Turbine
• 4 inch diameter impulse
turbine
• Creates 200 watts of
power
• Cost $1440
OCEAN THERMAL ENERGY
Ocean Energy
Energy from the moon
• Tides generated by the combination of the moon and
sun’s gravitational forces
• Greatest affect in spring when moon and sun
combine forces
• Bays and inlets amplify the height of the tide
• In order to be practical for energy production, the
height difference needs to be at least 5 meters
• Only 40 sites around the world of this magnitude
• Overall potential of 3000 gigawatts from movement
of tides
How it works
• First generation, barrage-style tidal power plants
• Works by building Barrage to contain water after high tide, then
water has to pass through a turbine to return to low tide
• Sites in France (La Rance), Canada (Annapolis), and Russia
• Future sites possibly on Severn River in England, San Francisco
bay, Passamaquoddy
Second-generation tidal power plants
• Barrage not need, limiting total costs
• Two types- vertical axis and horizontal axis
• Davis Hydro turbine….. Successfully tested in St.
Lawrence Seaway
• Harness the energy of tidal streams
• More efficient because they allow for energy production
on both the ebbing and surging tides
• One site has potential to equal the generating power of 3
nuclear power plants
Wave Power
World Wave Power Resources
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World Energy Council 2001 Survey stated the "potential exploitable wave energy" resources worldwide to be 2 TW.
For European waters the resource was estimated to be able to cover more than 50% of the total power consumption.
The wave market is estimated at $32 billion in the United Kingdom and $800 billion worldwide.
The United States has exhibited weak effort compared to overseas projects in Norway, Denmark, Japan and the United
Kingdom.
As of 1995, 685 kilowatts (kW) of grid-connected wave generating capacity was operating worldwide. This capacity
comes from eight demonstration plants ranging in size from 350 kW to 20 kW.
Until recently the commercial use of wave power has been limited to small systems of tens to hundreds of watts aboard
generate power
Oscillating Water Columns
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The Nearshore OWC rests directly on the seabed and is designed to operate in
the near-shore environment in a nominal mean water depth of 15m.
Nearshore OWC units also act like artificial reefs, improving environments for
fishing while calming the water for a harbor.
OWC designs typically require high maintenance, costly, taut moorings or
foundations for operation while only using the extreme upper strata of an
ocean site for energy conversion. While focusing devices are less susceptible
to storm damage, massive structuring renders them most costly among wave
power plant types.
Since 1965, Japan has installed hundreds of OWC-powered navigational buoys
and is currently operating two small demonstration OWC power plants. China
constructed a 3 kW OWC and India has a 150 kW OWC caisson breakwater
device.
A 75 kW shore-based demonstration plant by Queens University, Belfast,
using the OWC process described above has operated on the Scottish island of
Islay for 10 years
Floating Devices
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The Salter Duck, Clam, Archimedes wave swing, and other
floating wave energy devices generate electricity through
the harmonic motion of the floating part of the device. In
these systems, the devices rise and fall according to the
motion of the wave and electricity is generated through their
motion.
The Salter Duck is able to produce energy very efficiently,
however its development was stalled during the 1980s due
to a miscalculation in the cost of energy production by a
factor of 10 and it has only been in recent years when the
technology was reassessed and the error identified.
Tapered Channel Wave Power
These shoreline systems consist of a tapered channel which feeds into a reservoir constructed on a cliff. The
narrowing of the channel causes the waves to increase their amplitude (wave height) as they move towards
the cliff face which eventually spills over the walls of the channel and into the reservoir which is positioned
several meters above mean sea level. The kinetic energy of the moving wave is converted into potential
energy as the water is stored in the reservoir. The water then passes through hydroelectric turbines on the
way back to sea level thus generating electricity.
Geothermal Energy:
Natural heat energy produced
by the Earth
Geo (Earth) Thermal (Heat)
Tectonic Plates
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Plates are in constant motion (several
centimeters/yr).
When collision or grinding occurs, it can
create mountains, volcanoes, geysers and
earthquakes.
Near the junctions of these plates are where
heat travels rapidly from interior.
Layers of the Earth
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Heat flows outward from the center as a
result of radioactive decay.
The crust (about 30 and 60 km thick),
insulates us from the interior heat
A solid inner core followed by liquid outer
core, with the mantle by semi-molten
Temp at base of crust about 1000o C,
increasing slowly into the core.
Hot spots located 2 to 3 km form the surface
Types of Geothermal Energy
• Dry Steam Systems
• Wet Steam Systems
• Binary Cycle Systems
Dry Steam Systems
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Uses direct steam that shoots up through a well and
rock catcher, directly into the turbine.
Dry steam fields are rare.
Water boils underground and generates steam at
temps of 165oC and pressure of about 100 psi. Most
conventional fossil-fuel power plants run at 550o C
and 1000 psi.
Dry steam field of The Geysers were discovered in
1847 by a hunter looking for grizzly bear. At first,
he thought he had discovered the gates of hell. Used
for therapeutic hot springs and later for electric
power in 1920.
Wet Steam Systems
(AKA Flash Steam)
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Pulls high pressure hot water into low
pressure cool water tanks, resulting in
“flash steam” used to power turbines.
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Geothermal wells tap wet steam fields
deep in the earth’s surface.
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Taking a look at Yellowstone’s Old
Faithful,” allows us to see the principles
behind periodic geysers.
Temperatures in a wet steam system can
reach up to 370o C with boiling.
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Binary Cycle
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High temperature water brought from
geothermal reservoirs, is passed through heat
exchanger, containing pipe w/ secondary
fluids (Iso-butane) with a lower boiling
point.
The resulting flash steam power turbines,
creating an electrical current.
The geothermal water is never exposed to the
air and is injected back into the periphery of
the reservoir.
Geothermal Heat Pumps
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A geothermal heat pump system consists of
pipes buried in the shallow ground near the
building, a heat exchanger, and ductwork into
the building. In winter, heat from the
relatively warmer ground goes through the
heat exchanger into the house.
In summer, hot air from the house is pulled
through the heat exchanger into the relatively
cooler ground. Heat removed during the
summer can be used as no-cost energy to heat
water.
Seasonal GHP’s
Geysers
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Water at bottom of container is under
great pressure and will not boil until
temperature is above 100oC
When boiling begins, a great amount of
pressure is released, causing the water to
boil rapidly.
Steam-driven water, under great
pressure, rushes up to the neck, and
sprays steam into the air
Direct Use
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Hot water near the earth’s surface
can be pumped directly to groundlevel facilities.
This hot water can be used to heat
buildings, grow plants in a green
house, heat water for fish farms,
and pasteurize milk.
Much like hot water floor heating
in a house, this mass amount of
hot water can be pumped under
road to keep them from freezing.