Energy AlternativesCDAE-06Renewable Intro

Gary Flomenhofthttp://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

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Cost by Brand

• 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

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CDAE 170 Solar Building StrategiesPV system design Dec. 1, 2003

Gary FlomenhoftBSME, MAPP, CEEResearch AssociateGund Institute, SNR

Biomass: In VermontVT Energy Consumption Sources• Nuclear 36%• System 14%• Hydro Quebec 35%• Oil 2%• Gas 1%• Other Renewable 5%• Small Hydro 7% Since 1984, Vermont has met all increase

in energy demands(a total of 125 Mw) by renewable in-state sources:

-40 Mw Small Hydro

-73 Mw McNeil/Rygate (Biomass Plants)

-6 Mw Searsburg Wind Farm

EPA Landfill Incentive Programhttp://www.epa.gov/lmop/

Kinds of Biomass-traditional

• 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.

BiodieselBiodiesel 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

• 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

• 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• 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

• 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 EarthGeo (Earth) Thermal (Heat)

Tectonic Plates

• 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• 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

• 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)

• Pulls high pressure hot water into low pressure cool water tanks, resulting in “flash steam” used to power turbines.

• Geothermal wells tap wet steam fields deep in the earth’s surface.

• 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.

Binary Cycle

• 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• 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

• 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• Hot water near the earth’s surface

can be pumped directly to ground-level 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.