The document discusses and compares various renewable and non-renewable energy sources, outlining their advantages and disadvantages. It provides details on different renewable technologies like solar, wind, hydro, geothermal, tidal, and biomass power as well as non-renewable sources such as fossil fuels, coal, natural gas, oil, and nuclear power. The document also discusses energy efficiency and conservation as important tools for transitioning to cleaner energy.
2. Non-Renewable vs. Renewable
• Non-renewable – resources that cannot regenerate
quickly, takes thousands or millions of years.
• Renewable – resources that regenerate quickly
within decades.
3. Energy Efficiency and Energy Conservation
Energy efficiency – the amount of useful energy produced compared to
the amount wasted as heat (2nd Law of Thermodynamics); built into
the device or system, unavoidable waste
Examples of levels of energy efficiency:
human body:
20-25%
incandescent light bulb:
5%
internal combustion engine:
20-25%
steam turbine:
45%
Energy conservation – the effort to reduce the amount of energy used,
some waste can be avoided
5. Energy conservation and energy efficiency are presently the most
powerful tools in transition to a clean energy future.
As shown in the Energy Pyramid, renewable energy is an important
piece of our future energy, but the largest opportunities are currently
in energy conservation and efficiency.
6. Where does the electricity come from?
Renewables
•Wind
•Solar
•Hydropower
•Geothermal
•Tidal
•Biomass
•Wave
9. Wind Power
Advantages
•No fossil fuels are generated
•Take up less space than the average power station. Windmills
only have to occupy a few square meters for the base, this allows
the land around the turbine to be used for many purposes, for
example agriculture.
•Extraction of wind energy is much more efficient. The wind is free
•Represents a great energy source when combined with solar
panels
•45%–55% efficiency
10. Disadvantages:
• Less electricity than the average fossil fuels
• Construction can be very expensive and costly too
Rotating blades are a danger to birds
• Wind turbines can spoil the view and the rotating blades
are noisy
• It is unreliable, since wind speed can change at any time
12. Solar Power
The four technologies employed to make use of
solar energy are:
•Daylighting
•Passive Solar Heating
•Active Solar Heating
•Concentrating Solar Thermal
•Photovoltaic(PV)
15. Passive Solar Heating: takes advantage of Sun’s
warmth and materials that absorb that warmth during the
day/release it at night when heat is needed.
16. Active Solar Heating: solar collectors
concentrate the sun’s power on dark color plates
that absorb heat. Air or liquid flows through tubes
and warmed by the plates.
Flat Plate
Collector
Evacuated Tube
Collector
16
17. Concentrating Solar Thermal: mirrors direct sunlight
on one point. Water is turned into steam with this heat.
The steam turns a turbine to create electricity.
20. Disadvantages:
•Flooding - large areas of land are flooded to
create dams and reservoirs.
•Consequent impacts on people, animals and
vegetation. When submerged vegetation
decays, it produces methane and releases
mercury.
•Impact stream flow
•Traps sediments and nutrients
•Decreases dissolved oxygen in water
21. Geothermal Power
Advantages
•Less costs
•Consumes less electricity
•More efficiency than gas and oil furnaces
•A highly acceptable solution as greenhouse gases and air
pollutants levels are less
•Cools and operates quietly
•15%–20% efficiency
23. Tidal Power
Tidal energy is hydropower which converts the
energy of tides into electricity or other forms of
power. Tides are more predictable than wind energy
and solar power.
24. Advantages
• More predictable than wind energy and solar
power
• Doesn’t depend on whether
• No pollution
• Requires no fuel
• Not expensive to maintain
• 95% efficiency
25. Disadvantages
• A barrage is expensive to build and affects a wide
area
• Environment is being affected
• Provide power for only 10 hours a day
• Cannot be installed everywhere
30. Advantages
• Ample supply for 35-84 years
• Low cost
• High net energy yield
• Easily transported within
and between countries
31. Disadvantages
• Artificially low price encourages waste and
discourages search for alternatives
• Air pollution, releases CO2 when burned
• Moderate water pollution
32. Natural Gas – another fossil fuel
Mixture of gases
• 50–90% Methane (CH4)
• Ethane (C2H6)
• Propane (C3H8)
• Butane (C4H10)
• Hydrogen sulfide (H2S)
33. The use of Natural Gas
• Produce electricity
• Heat homes - inside homes, water heater
• Industry - heat for warmth and producing
things
• Vehicles
• Cooking
34. Advantages
• High net energy yield
• Low cost
• Less air pollution than other fossil fuels
• Lower CO2 emission than other fossil fuels
• Moderate environmental impact
• Good fuel for fuel cells and gas turbines
35. Disadvantages
• Releases CO2 when burned
• Leaks of methane – GHG
• Shipped across ocean as highly explosive
• Sometimes burned off and wasted at low price
• Fractioning can cause groundwater
contamination and earthquakes
37. Coal Power
Disadvantages:
•High GHG Emissions - it produces carbon dioxide and
other gases that contribute to acid rain.
•Harmful extraction process
•High water demand
•Thermal discharge - the process is only 30 percent
efficient. That is, about 70 percent of the energy
produced is lost as heat before it reaches the
consumer
•Waste created
38. Acid Mine Drainage
Acid mine drainage comes mainly from abandoned
coal mines and active mining.
39. Nuclear Power - Uranium
Advantages
•There are no greenhouse gas emissions.
•A small amount of nuclear fuel
will produce a great amount of
energy
•20%–50% efficiency
40. Nuclear power meets more than 50 per cent of
Ontario's electricity needs.
Energy Output by 2008
41. Ontario Power Generation owns and operates the Pickering
and Darlington Nuclear Power Stations. The two stations have
a combined generating capacity of about 6,600 megawatts.
Pickering Nuclear Power Stations is one
of the world's largest nuclear generating
facilities.
Capacity: 3,100 MW
42. Darlington Nuclear Power Stations sits on the shores of Lake Ontario,
roughly 60-kilometres east of Toronto.
Capacity: 3,500 MW
43. Disadvantages
• Thermal Discharge - when cooling water is
discharged into the lake, the temperature of water
rises.
• Radioactive Waste - power plants are very
expensive and radioactive waste must be properly
stored.
44. Three Mile Island
• March 29, 1979, a reactor near Harrisburg, plant in Pennsylvania,
lost coolant water because of mechanical and human errors and
suffered a partial meltdown
• 50,000 people evacuated & another 50,000 fled area
• Unknown amounts of radioactive materials released
• Partial cleanup & damages cost $1.2 billion
• Released radiation increased cancer rates.
45. Chernobyl
• April 26, 1986, reactor explosion, Ukraine
flung radioactive debris into atmosphere
• Health ministry reported 3,576 deaths
• Green Peace estimates 32,000 deaths
• About 400,000 people were forced to leave their homes
• ~160,000 Km2 contaminated
• > Half million people exposed to dangerous levels of
radioactivity, causing cancer, tumors, eye cataract, and
genetic mutations
• Cost of incident > $358 billion
47. Fukushima disaster – Japan, March 2011
before
Earthquake, followed by tsunami –
subsequent loss of power to cool reactors,
plus fire at plant
48. Dec 14
Classroom Electricity Audit
- 5 appliances
- plug in
a Wattmeter to measure the amount of energy it uses
Notas do Editor
The four technologies employed to make use of solar energy are: Daylighting- the use of natural sunlight to brighten the building’s interior. Passive Solar Heating- takes advantage of Sun’s warmth and materials that absorb that warmth during the day/release it at night when heat is needed. Active Solar Heating- solar collectors concentrate the sun’s power on dark color plates that absorb heat. Air or liquid flows through tubes and warmed by the plates. Concentrating Solar Thermal- mirrors direct sunlight on one point. Water is turned into steam with this heat. The steam turns a turbine to create electricity. Photovoltaic(PV)- converts sunlight directly to electricity.
Langston High School in Arlington, VA and Caywood Elementary in Kentucky use daylighting to keep energy costs down.
These homes in Montana and California with a passive solar design heats the home in the winter and cools the home in the winter.
Indirect Water Heater : The most common collector is called a flat-plate collector . Mounted on the roof, it consists of a thin, flat, rectangular box with a transparent cover that faces the sun. Small tubes run through the box and carry the fluid — either water or other fluid, such as an antifreeze solution — to be heated. The tubes are attached to an absorber plate, which is painted black to absorb the heat. As heat builds up in the collector, it heats the fluid passing through the tubes. Evacuated-tube collectors can achieve extremely high temperatures (170°F to 350°F), making them more appropriate for commercial and industrial application. However, evacuated-tube collectors are more expensive than flat-plate collectors, with unit area costs about twice that of flat-plate collectors. Evacuated tube collectors are usually made of parallel rows of transparent glass tubes. Each tube contains a glass outer tube and metal absorber tube attached to a fin. The fin is covered with a coating that absorbs solar energy well, but which inhibits radiative heat loss. Air is removed, or evacuated, from the space between the two glass tubes to form a vacuum, which eliminates conductive and convective heat loss. The storage tank then holds the hot liquid. It can be just a modified water heater, but it is usually larger and very well-insulated. Systems that use fluids other than water usually heat the water by passing it through a coil of tubing in the tank, which is full of hot fluid. Solar water heating systems can be either active or passive, but the most common are active systems. Active systems rely on pumps to move the liquid between the collector and the storage tank, while passive systems rely on gravity and the tendency for water to naturally circulate as it is heated. More information available at http://www1.eere.energy.gov/solar/sh_basics_water.html
A clean, large-scale solar thermal technology known as concentrating solar power is used in special power plants (Concentrating Solar Power or CSP plants) that use different kinds of mirror configurations to convert the sun's energy into high-temperature heat. The heat energy is then used to generate electricity in a steam generator.
Photovoltaic systems convert sunlight directly into electricity, and are potentially one of the most useful of the renewable energy technologies. Also known as solar cells, PV systems are already an important part of our lives. The simplest systems power many of the small calculators and wrist watches we use everyday.