Global Ozone Project Curriculum
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Transcript of Global Ozone Project Curriculum
Global Ozone Project Curriculum
Lesson:Renewable Energy
Rev 10ABrian Carpenter, Jessa Ellenburg and John Birks
Learning Objectives
At the end of this lesson students should be able to:
• Identify Non-Renewable Energy Sources.
• Identify the top five Renewable Energy Sources.
• Identify Pros and Cons for each Renewable Energy Source.
Global Ozone Project Curriculum
Part 1:Introduction to Energy Use
Energy Introduction
• Heat Engine: a device that can convert heat energy to mechanical energy.– Fancy name for a car engine, a power plant, your
refrigerator, air conditioner, etc.
• Efficiency of a heat engine is expressed in terms of the temperature difference between the hot side and the cold side. Efficiency = (Thot – Tcold)/Thot
• Cars are only about 20 to 30% efficient. Coal fired power plants are around 35% efficient.
Electricity Introduction
Generating Electricity– To get electricity, we convert
mechanical energy to electrical energy
– Converting mechanical energy to electricity is done by electromagnetic induction discovered by Michael Faraday in 1831.
Michael Faraday
Electricity
Generating Electricity
• Spinning conductive wires inside a magnetic field causes electrons to move inside the wires, and moving electrons are electricity.
• We can use both renewable and nonrenewable energy sources (fossil fuels) to do this.
Energy Sources
Major Renewable Sources • Solar• Hydropower• Wind• Biomass• Geothermal
Major Non-Renewable Sources• Oil • Coal• Natural gas• Nuclear• Fuelwood
From Energy Sources to Electricity
US vs. Global Energy Use
US Energy Use Global Energy Use
Energy Production by State
Global Ozone Project Curriculum
Part 2:Renewable Energy Technologies
Renewables
Major Renewable Energy Sources • Hydropower• Biomass• Geothermal• Wind• Solar
Active SolarWe utilize two types of Solar Energy:
Active Solar & Passive Solar
Active Solar:Technologies like Solar Panels (Photovoltaics) are used to convert solar energy into electrical energy.
Passive Solar - Heating and Cooling
Passive Solar: Direct use of sun’s heat energy for home heating.
Passive Solar – Water Heating
Another use of passive solar – to heat water for household use.
Solar Potential for the US
Costs of Solar Electricity (Active Solar)
Costs of PV electricity:• Industrial system (500 kilowatt system, about $2.5M).• Sunny day: 15-20 cents/kWhr, 35-55 cents on a
cloudy day.• Home system (2 kilowatt system, about $18,000).• Sunny day: 35 cents/kWhr, 80 cents on a cloudy day.
Compare this with electricity from coal:• Peak cost: 15 cents/kilowatt-hour.• Off-peak cost: 10 cents/kilowatt-hour or less.
Pros and Cons of Active Solar (Solar Panels)Pros:• Solar panels give off no pollution, the only pollution produced as a result of solar panels is the
manufacturing of these devices in factories, transportation of the goods, and installation.• Solar energy produces electricity very quietly.• The ability to harness electricity in remote locations that are not linked to a national grid. • The installation of solar panels in remote locations is usually much more cost effective than laying the
required high voltage wires.• Solar energy can be very efficient in a large area of the globe, and new technologies allow for a more
efficient energy production on overcast/dull days.• Space is not an issue because solar panels can be installed on top of many rooftops.• Solar is cost-effective. Although the initial investment cost of solar cells may be high, once installed, they
provide a free source of electricity, which will pay off over the coming years.• Utilizing solar energy decreases dependence on fossil fuels.
Cons:• The major con of solar energy is the initial cost of solar cells. Currently, prices of highly
efficient solar cells can be above $1000, and some households may need more than one. • Solar energy is only able to generate electricity during daylight hours. • The weather can affect the efficiency of solar cells.• Pollution can affect a solar cell’s efficiency.
Pros and Cons of Passive Solar Heating/CoolingPros:• Renewable. No fuels required.• Non-polluting. Carbon free except for
production and transportation.• Simple, low maintenance.• Hot water provides some storage capacity.• Operating costs are near-zero.• Quiet. Few or no moving parts.• Mature technology.• Good return on investment.• High efficiency.• Can be combined with photovoltaics in
highly efficient cogeneration schemes.
Cons:• Intermittent.• Low energy density.• Does not produce electricity.• Supplemental energy source or storage
required for long sunless stretches.• Expensive compared to conventional water
heaters.• Construction/installation costs can be high.• Hard to compete against very cheap natural
gas.• Some people find them visually unattractive.• Manufacturing processes can create
pollution.• Installers not available everywhere.• Generally not practical to store or sell excess
heat.• Produce low grade energy (heat vs.
electricity).• Dependent on home location and orientation.
Future of Solar PowerWays to improve:1. Concentrators: these are mirrors that
concentrate the sun’s energy to improve efficiency.
2. Hybrid Solar Systems: combine solar with other forms of energy production to make cheaper and more reliable. For example, solar-wind, and solar-hydro.
3. Consider Cost of Pollution: Cost of coal-based electricity is cheaper in part because pollution is not factored into the cost. Cost of pollution from solar (in manufacturing process) would be much less.
Hydropower
Basics:• Form of solar energy, as the
sun drives water evaporation from the ocean and winds carry the moisture overland.
• Largest form of alternative energy used today.
• Industrialized countries have already tapped much of their potential.
• Non-industrialized countries have the most untapped potential.
Hydropower - DamsDams• Height of dam and mass
of water determine useful energy.
• Efficiency is very good to excellent, generally 80 to 90% efficient in converting potential energy to electrical energy.
• Potential Energy = mass*gravity*height
Hydropower Generation
Hydroelectric power production costs less than half of fossil fuel derived electricity (does not include construction costs).
Future of Hydropower
Tidal Power: Propeller Systems
Tidal Power: Wave Systems
Tidal Power:Enclosures
Pros and Cons of Hydropower
Pros:• Very clean.• Cheap.• Flood control (primary reason for dams).• Multiple crops per year possible.
Cons:• Potential is limited globally to about 5 to 10% of energy needs.• Dependability is an issue; prolonged droughts can cut electrical production in half or more.• Dams have drawbacks, including:
Environmental impactsLoss of nutrient flow down riverLoss of sediment flow down riverSedimentation behind the dam limits lifetime of the damFlooding of scenic areas and archaeological sitesEcosystem below the dam is usually changed by having colder, nutrient poor waterAestheticsLoss of wild rivers
Wind Power
Basics• Use dates back
thousands of years in the form of windmills, sailing ships, etc.
• Typical efficiency is about 30%. Maximum theoretical efficiency is thought to be about 60%.
Windmills
US Wind Power Potential
Midwest has more than 90% of US potential
Wind Power Pros/Cons
ProsCost is very competitive, production costs are about 5 cents per kilowatt-hour (coal electricity is around 15 cents). This is down from 7 to 10 cents per kilowatt-hour in 1995 and 15 cents per kilowatt-hour in the 1980's.• In this case subsidies helped to create a viable market.• It is estimated that the costs could be lowered to 3-4 cents per kilowatt-hour as wind
technology improves. Improvements in technology may also open less windy areas up for economically useful and viable wind power.
Cons• Reliability is a key issue, as the wind does not always blow. Requires a storage
mechanism that compensates for reliability.• Recently, aesthetics has become a significant issue.• Killing of birds and bats from high blade tip speeds.• Disruption of natural wind patterns.
Biomass
Basics• Energy from the sun, via photosynthesis in
plants.• This is the same energy we use as food.• This is the same energy that made fossil
fuels; fossil fuels are concentrated over time by the heat and pressure within the Earth.
• The oldest form of energy used by humans: wood fire, a form of biomass.
Biomass
What is biomass?
• Any plant tissue can be used for energy, but the faster the plant grows, the more useful it is.
Biomass
How does it work? How do we convert biomass energy to useful forms of energy?• Direct burning• Gasification• Cofiring• Fermentation
Future of Biomass
• GMO “Energy Crops” - like Poplar and Willow trees which have been genetically engineered and bred for rapid growth
• Algae - also grows rapidly• Biodiesel - Canola and Sorghum, etc.• Cellulosic Ethanol
Developing ideas
Biomass Pros and ConsPros:• Truly a renewable fuel• Widely available• Generally low cost inputs• Abundant supply• Can be domestically produced
for energy independence• Low carbon, cleaner than
fossil fuels• Can convert waste into energy,
helping to deal with waste
Cons:• Energy intensive to produce• Land utilization can be considerable • Requires water to grow• Not totally clean when burned (NOx, soot, ash,
CO, CO2)• May compete directly with food production (e.g.
corn, soy)• Some fuels are seasonal• Energy required to transport• Overall process can be expensive• Some methane and CO2 are emitted during
production• Not easily scalable
Geothermal Power
Geothermal Electricity
Geothermal in the Home
Geothermal Potential in the US
Future of Geothermal
Ocean Thermal Energy Conversion (OTEC):• This is a special case of geothermal energy, as the source of the energy is
the sun, warming the surface waters of the ocean.• Uses the temperature difference between cooler deep and warmer shallow
or surface ocean waters to run a heat engine and produce useful work, usually in the form of electricity.
• The cold water typically comes from about 1000 meters.
Attractions of OTEC are:• Steady source of energy (all day, all year).• Potential large in warm areas (Florida, Hawaii) requiring air conditioning.• Could use this energy to create hydrogen gas from seawater.• Could be used to desalinize water.• Mariculture (seafood farming)
Geothermal Pros and ConsPros:• Almost entirely emission free.• The process can scrub out sulfur that might
have otherwise been released.• No fuel required (no mining or
transportation).• Not subject to the same fluctuations as
solar or wind.• Smallest land footprint of any major power
source.• Virtually limitless supply.• Inherently simple and reliable.• Can provide base load or peak power.• Already cost competitive in some areas.• Could be built underground.• New technologies show promise to utilize
lower temperatures.
Cons:• Prime sites are very location-specific.• Prime sites are often far from
population centers.• Losses due to long distance
transmission of electricity.• Water usage.• Sulfur dioxide and silica emissions.• High construction costs.• Drilling into heated rock is very
difficult.• Minimum temperature of 350F+
generally required.
Emerging Technologies
There are many interesting emerging renewable technologies. A few examples are:Soccer Ball ChargerSpray-on Solar PanelsGreen Gasoline
What will you come up with??