Energy from Wind and Moving Water

oil in various forms such as gasoline and heating oil.
natural gas.
electrical energy generated from
- hydroelectric plants
- conventional thermoelectric plants which burn fossil fuels (natural gas or oil or coal) that produce heat to drive steam turbines linked to electrical generators.
- nuclear thermoelectric plants that use the heat produced by nuclear fission to drive steam turbines linked to electrical generators.
- wind and solar sources (minor applications in Canada).
minor sources include energy from wood burning (mostly rural home heating).

Teacher's Notes

This unit covers Energy (from wind and moving water).

Energy and force are fairly intricate physical concepts. The trick is to lay the groundwork for a more sophisticated understanding of energy and force without prejudicing the student's notions to include popular misconceptions about energy and force.

Energy

Energy is the property of an object or substance which allows it to do work . Energy is quantified using units of joules (J) . In this lesson it is important to emphasize that energy is not consumed in the sense that it is destroyed, but rather energy is absorbed (sometimes to do work or stored or released as heat) and then discarded to the environment, ultimately as heat.

Things to emphasize

Energy never gets used up. Think of energy as Mother Nature's money. Whenever something happens energy must be exchanged. Sometimes things gain energy, sometimes things lose energy, but energy is neverdestroyed.
Energy can be stored by objects (sort of like putting money in the bank). Eventually, however, this energy will be spent and passed on to some other object or objects.
Humans need energy.
All energy used on Earth comes from the Sun(unless you have nuclear or geothermal energy sources).
In general, energy cannot be seen. We can only detect its presence other ways. It's a bit like seeing a castle. We can't actually see the owner's money, but we can assume they have lots of it!

Energy from things that move

The key concepts are kinetic energy (1/2mv²) and the conservation of energy.

There are many subtle concepts related to the conversion of energy from one form to another.

Similarly, the energy pathway(s) involved from (usually) the Sun to the execution of useful work (such as pumping water or milling flour) is not usually obvious. The activities here are to illustrate one segment of the energy pathway, that is the conversion of kinetic energy to mechanical energy using windmills and waterwheels.

Even in these examples the conversion of energy is subtle. In a very real sense mechanical energy is an other manifestation of kinetic energy (in the moving parts of a machine).

Energy is transferred when moving things stop (moving)

All moving things have energy simply as a result of the fact that they are moving. In fact they gained energy when they started moving. To put it another way, energy must be put into something to get it moving, and usually, the more energy that is put into an object, the faster it moves.

The question is, where does the energy go when an object slows down or stops?

The answer is, you can get the energy back! When you slow down or stop anything that is moving, energy will be released. Often the energy is released as heat.

For example, to stop a moving car you use its brakes. To stop a moving bicycle you use its brakes (not your shoes). To stop a moving train the engineer uses its brakes. Brakes are simply devices that convert the energy of motion into heat. Unfortunately this is usually wasted energy and its only use is to heat up the air around the brakes.

But people have invented machines to use the energy released by stopping or slowing down moving things to do useful work.

Two good examples are

The Windmill: Slows down moving air and uses the energy released (by the air) to turn a shaft which can be hooked up to machinery such as a water pump.
The Waterwheel: Slows down moving water and uses the energy released (by the water) to turn a shaft which can be hooked up to machinery such as a saw for cutting timbers into boards.

Both of these machines extract energy from moving fluids (air and water) by slowing them down. The best windmill and the best waterwheel would cause the moving air and the moving water to stop completely.

Activity

Build an "Atmospheric Molecular Energy-grabber"

You can impress your friends and family by telling them that you are building (or have built) an amazing "Atmospheric Molecular Energy-grabber".

INSTRUCTIONS

Aha

Both waterwheels and windmills extract energy by slowing down the speed of the water or air which passes through them.

The Prairie Windmill

The windmill is an excellent example of using natural sources of energy to do useful work. The prairie windmill works well because there is an abundance of strong daily wind which blows across the flat prairies.

Windmill
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The Waterwheel

Waterwheels take many shapes, forms, and sizes, but they can generally be grouped into two main types. As shown below, they are known as "undershot" or "overshot", depending upon whether the water goes over or under the waterwheel.

Waterwheel
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What if

Some water powered mills had a penstock that could be moved back and forth. In one position it would allow the water to flow over the top of the wheel (overshot) and at other times it could be set up to go under the wheel (undershot). Why would the builders of the mill wish to do this? Why didn't they just decide on one setting or the other and build it permanently that way?

A "WOW" fact

The space shuttle has a speed of about 7 kilometres per second when it is in orbit. In order to land it must eventually brake to a speed of about 0.05 kilometres per second. In slowing down to this speed the shuttle must release a lot of energy; more energy in fact than if the entire shuttle and its cargo where made of high explosives!

The space shuttle must release this energy slowly. How is this done?

Assessment Rubric

R	Level 1	Level 2	Level 3	Level 4
significantly below the standard	approaches the standard		the standard	exceeds the standard
(below 50%)	(50-59%)	(60-69%)	(70-79%)	(80-100%)
Understanding of Basic Concepts
produces insufficient evidence to demonstrate learning demonstrates significant misconceptions requires additional learning activities and remediation	demonstrates limited understanding of Newton's Laws of Motion	demonstrates some understanding of Newton's Laws of Motion	demonstrates general understanding of Newton's Laws of Motion	demonstrates thorough understanding of Newton's Laws of Motion
	by providing partial explanations of how energy is transformed, stored and released	by providing partial explanations of how energy is transformed, stored and released	by providing complete explanations of how energy is transformed, stored and released	by providing complete explanations of how energy is transformed, stored and released
	with significant misconceptions / inaccuracies	with minor misconceptions / inaccuracies	with no significant misconceptions / inaccuracies	with no misconceptions / inaccuracies
Application of Critical and Creative Thinking Skills and/or Processes
produces insufficient evidence to demonstrate learning requires additional learning activities and remediation	with limited effectiveness, applies appropriate skills/strategies to: -construct a basic wind turbine and; -modify the structure to create a simple machine capable of performing work	with some effectiveness, applies appropriate skills/strategies to: -construct a basic wind turbine and; -modify the structure to create a simple machine capable of performing work	with considerable effectiveness, applies appropriate skills/strategies to: -construct a basic wind turbine and; -modify the structure to create a simple machine capable of performing work	with a high degree of effectiveness, applies appropriate skills/strategies to: -construct a basic wind turbine and; -modify the structure to create a simple machine capable of performing work
Communication of Required Knowledge
produces insufficient evidence to demonstrate learning requires additional learning activities and remediation	communicates unclearly or imprecisely	communicates with some clarity and precision	communicates with general clarity and precision	communicates clearly and precisely
	rarely using appropriate scientific conventions, vocabulary, and terminology	sometimes using appropriate scientific conventions, vocabulary, and terminology	usually using appropriate scientific conventions, vocabulary, and terminology	always using appropriate scientific conventions, vocabulary, and terminology
Application of Required Knowledge
produces insufficient evidence to demonstrate learning demonstrates significant misconceptions requires additional learning activities and remediation	makes very simple connections between science concepts related to energy transfer and their practical applications in everyday life	makes simple connections between science concepts related to energy transfer and their practical applications in everyday life	makes connections of some complexity between science concepts related to energy transfer and their practical applications in everyday life	makes complex connections between science concepts related to energy transfer and their practical applications in everyday life

Curriculum Expectations

Quebec Curriculum Expectations:

The Physical Science (Physical Environment) course is designed to help the students :

gain knowledge of certain physical phenomena in the environment, and consequently, learn about the properties of matter;
develop certain skills necessary for scientific experiments;
develop certain attitudes regarding the scientific method, such as a critical sense and a taste for research. This will help the students increase their awareness of the impact of modern technology on the physical environment.

Pan-Canadian Curriculum Expectations:

Grade 11/12

Curriculum Strand - Energy and Momentum

Knowledge Expectations

analyse quantitatively the relationships among mass, height, speed, and heat energy using the law of conservation of energy.
apply quantitatively Newton's laws of motion to impulse and momentum.
describe quantitatively mechanical energy as the sum of kinetic and potential energies.
analyse quantitatively problems related to kinematics and dynamics using the mechanical energy concept.
analyse common energy transformation situations using the work-energy theorem.
determine the per cent efficiency of energy transformations.

Skills Expectations

compile and display evidence and information, by hand or computer, in a variety of formats, including diagrams, flow charts, tables, graphs, and scatter plots.
provide a statement that addresses the problem or answers the question investigated in light of the link between data and the conclusion.
construct and test a prototype of a device or system and troubleshoot problems as they arise.
evaluate a personally designed and constructed device on the basis of criteria they have developed themselves.
identify questions to investigate that arise from practical problems and issues.
design an experiment identifying and controlling major variables.
evaluate and select appropriate instruments for collecting evidence and appropriate processes for problem solving, inquiring, and decision making.
carry out procedures controlling the major variables and adapting or extending procedures where required.
select and use appropriate numeric, symbolic, graphical, and linguistic modes of representation to communicate ideas, plans, and results.
identify multiple perspectives that influence a science-related decision or issue.

Science, Technology, Society and the Environment Expectations

analyse and describe examples where technologies were developed based on scientific understanding.
describe and evaluate the design of technological solutions and the way they function, using scientific principles.
analyse why scientific and technological activities take place in a variety of individual and group settings.
identify various constraints that result in tradeoffs during the development and improvement of technologies.
explain the importance of communicating the results of a scientific or technological endeavour, using appropriate language and conventions.
distinguish between scientific questions and technological problems.
analyse why and how a particular technology was developed and improved over time.
distinguish between questions that can be answered by science and those that cannot.
propose courses of action on social issues related to science and technology, taking into account an array of perspectives, including that of sustainability.
Webliography

Canadian Renewable Energy Network
Link to information on renewable energy. Discover how to reduce energy costs in the home and learn about technologies such as hydroelectric and solar energy.
Natural Resources Canada

Earth and Geothermal Energy
Read about Eco-Industrial Parks, synergistic projects that are cost-effective, reduce most pollutants simultaneously, provide benefits to health and the ecosystem and create investment and value-added jobs.
Natural Resources Canada

Electric Power: A Canadian Speciality
Learn how electricity has become a cornerstone of the Canadian economy and Canadian life.
Government of Canada

Energy Consumption
View several charts that graph Canada's energy consumption over time and read about the factors that influence the statistics, such as climate and standard of living.
Environment Canada

Energy in Canada
Link to information on climate change, energy efficiency and renewable energy. Read about energy policies and learn about international priorities.
Natural Resources Canada

Hydroelectric Energy
Learn about hydroelectric energy, a renewable energy source dependent upon the hydrologic cycle of water, which involves evaporation, precipitation and the flow of water due to gravity.
Natural Resources Canada

Promoting Renewable Energy
Find out how renewable energy sources, which produce electricity or thermal energy without depleting resources, are promoted in Canada.
Natural Resources Canada

Prepared by the YES I Can! Science team
www.yesican-science.ca