Physical Science Lab

Wind Power

2008 Summer Institute

DESCRIPTION

Teams will build a rotor blade assembly (similar to a propeller) attached to a compact disc (CD). They will also participate in an activity testing their knowledge about wind and power generation. The team whose device score combined with the activity score is the highest wins.

EVENT PARAMETERS/CONSTRUCTION

a. Each team will bring two pre-constructed rotor blade assemblies attached to a standard CD in a box.

b. Resource materials may be used. Materials such as pencils, pens, protractors, rulers, nonprogrammable calculators, and any other similar tools may also be used during the activity.

c. Prior to the competition, the event supervisor will announce which kind and size of multispeed fan will be used at the competition. (A box fan is recommended)

d. Impact goggles must be worn during the event.

e. The CD must fit on the mount found in a standard CD player. Modification of the CD IS allowed. When mounted, the assembly must fit within a 30 cm diameter circle. The blade may be made of any nonmetallic substance. No commercially available blades either modified or unmodified are permitted.

f. Blade assemblies must be placed in a box and labeled with the team number for impound.

THE COMPETITION

a. Two mounting areas (High and Low speed) will be prepared by the event supervisor. The areas will consist of a fan and generator (from a portable CD player. Consult www.soinc.org for setup) with a voltmeter/multi-meter. The motor from the CD player can be mounted with a ring clamp.

b. For each fan speed, when the students are ready they will tell the event supervisor to start recording the average voltage during a one-minute interval. Students may use either blade assembly in front of either fan. However, once mounted, they cannot be switched.

c. The fan used must have a fixed position whose bottom is at least 15 cm above the table. Students may orient their blade assembly in any direction or position in space; however, the position of the blade assembly may be no closer than 5 cm measured from the front grill of the fan to the closest part of the blade assembly.

d. Teams will have 10 minutes to set up and complete the device testing.

e. Teams will also engage in activities that can include questions, data analysis, or experiments. Teams will have up to 40 minutes to complete this part.

SAMPLE

STATIONS/QUESTION TOPICS:Though stations are encouraged supervisors may

choose to use questions in test format to evaluate student knowledge on such topics such as: wind power, solar power, geothermal energy and other alternative energy forms; advantages and disadvantages of these forms of energy to society; environmental concerns regarding current use and practices regarding energy; and interpretation of data regarding energy usage and availability

SCORING

The final score will be determined adding both the device scores and the activity score. To calculate the final score determine your activity score on a 300-point base and equate one millivolt to one point for the device score.

Device Score = Low speed voltage (mV) + High speed voltage (mV)

Final score = Device Score + Activity Score (300 point base)

If the device fails during a run the score at that speed will be zero.

Ties will be broken by the best high-speed performance.

Wind WisdomThere are probably two main reasons for the increasing

interest in wind power. First, most electricity generated today uses non-renewable fuels such as coal, oil and gas. These contribute vast quantities of carbon dioxide to the atmosphere, which many scientists think cause an enhanced greenhouse effect, leading to a warming of the Earth's atmosphere.

The second reason is that advances in wind power science and technology are reducing the cost of wind power to a point at which it is becoming competitive with many other energy sources (at about 8 cents per kilowatt hour). The world has long been searching for a non-polluting, renewable source of energy that is as cheap as coal and oil.

A doubling of wind speed results in as much as an eight-fold increase in power.

The length of the rotor blades is also important – doubling the diameter of the circle made by the blades produces a four-fold increase in power

Since the wind is slowed by friction with the land surface. Modern wind turbines are mounted on towers 40-60 metres high to expose the blades to a higher wind speed.

Infrasound decibel levels are about 15 to 45 db. Scientists continue to work to “cancel out” unwanted sound.

How would increased use of windfarms affect birds, and bats?

Would these farms further disrupt routes of bees?

Resources

http://www.auswea.com.au/WIDP/factsheets.htm (Australian energy association)

http://www.abc.net.au/rn/talks/bbing/stories/s1083409.htm

http://windpower.fleettrikes.com/lessons.htm (Windpower Lessons Learned)

http://www.kidwind.org/lessons/BBwindpowerbasics.html (lesson plans - friendly)

PHYSICAL SCIENCE LAB

SOLAR POWER

DESCRIPTION

In this event students will demonstrate knowledge and process skills needed to solve problems and answer questions regarding all areas of alternative energy sources. In addition they will design a solar collector in such as way as to derive the greatest efficiency of the energy provided by a single light source. They must keep a log of design modifications and data collected which will be submitted during part 2 of the competition. There will be no impound for this event.

EVENT PARAMETERS

Students may bring a pencil and use a non-programmable calculator. All reference materials to be used during part two of the competition must be secured in a 3-ring binder, must be 3-hole punched and inserted in the binder so that regardless of orientation none can fall out. Students will also prepare data tables and a log that must be submitted to the supervisor during part 1

THE COMPETITION

The competition will consist of two parts. During the first part of the competition (that may be run concurrently with the second part) students will demonstrate the efficiency of their solar collector constructed prior to the competition.

a) Students will be given 5 minutes to set up their solar collector. The solar collector may be constructed using cardboard, aluminum foil, reflective fabric or material, glue, tape, mirrors, tiles, etc. It must be able to fit into an imaginary 35 cm cube when set up for testing and must be made in such a way as to allow easy access for inserting their beaker of water and a thermometer/probe.

a) Each competitive team will be given a 250 ml beaker. The event supervisor will supply each team with 100 ml of water from a common source. The students will place the beaker containing the water inside the collector.

b) No other sources of energy (electrical, chemical, fire, etc.) will be allowed. Nothing may be added to the water or the container. No chemicals producing exothermic reactions maybe used.

d) Each testing station will have a high intensity lamp with a 150 watt bulb mounted above the area where testing will take place. The distance from the bottom of the bulb to the top of the imaginary cube in which the collector is placed will be announced at the site. The bottom of the bulb will be no closer than 5 cm to the top of the imaginary cube. Students will estimate the change in temperature their device will achieve based on their data charts that must be submitted at this time. That prediction will be recorded on their score sheet by the supervisor.

e) A probe/digital thermometer will be inserted into the water to measure the initial temperature of the water. This temperature will be recorded to the nearest tenth of a degree by the supervisor. The thermometer will then be removed and the light source turned on. A stopwatch will be started at the time the light is turned on. At the end of 10 minutes the light will be turned off and the thermometer/probe will again be inserted, read and recorded to the nearest tenth of a degree to determine the amount of temperature gained.

During the second part of the competition students will be presented with questions and hands-on tasks at stations requiring them to draw and label diagrams to demonstrate knowledge of introductory concepts, record observations, make predictions, interpret data, generate inferences, solve problems and formulate and evaluate hypothesis. The following topics may be included:

a) Basic information and definitions about energy, work, heat and heat transfer including, but not limited to concepts of heat, temperature, temperature scales, thermal energy, conduction, convection, radiation and insulation.

b) General information about renewable energy including but not limited to solar, wind, hydroelectric, tidal, oceanic tidal energy currents (OTEC), and geothermal.

c) General information about energy conservation practices including but not limited to recycling, reusing, and using materials with greater efficiency.

d) Mathematical relationships and equations used in determining heat loss and heat gain, specific heat, and heat transfer.

Scoring

The highest final score wins. The following equation will be used to calculate the final score:

Part 1 raw score (based on 100 points) + 5(Number of degrees increase in temperature - student estimated change) = Final score. Ties will be broken by preselected questions from Part 1 of the event.

Heat and Temperature

Temperature scales (K, ºC, ºF)

Units of measurement (calorie,joules, etc.)

Heat transfer

-conduction

-convection

-radiation

Definitions (work, energy)

OTEC has been around for many years (80?), but the engineering involved seemed daunting.

The amount of ocean available makes this appear much more viable.

What is needed is to create a heat engine to use the difference between the deep cold waters of the ocean and the warmer upper levels. A heat engine is a thermodynamic device placed between a high temperature reservoir and a low temperature reservoir. As heat flows from one to the other, the engine converts some of the heat energy to work energy.

Ocean Thermal Energy Conversion

Other types of renewable energy

Solar energy

Pros Cons

-Saves money (for home owner) Initial cost high

-Environmentally friendly Requires large area for panels

-Supports local economy At mercy of weather/climate

-Low maintenance Solar cars are slow

More Renewable Forms

Hydroelectric EnergyPros

-Inexhaustible fuel source

-Minimal environmental impact

-Viable source-relatively useful levels of energy production

-Can be used throughout the world

Cons

-May affect fish (can minimize with fish ladders)

-Depends on presence of fast moving streams

TidalPros

-Does not generate emmissions or wastes-Uses an abundant, inexpensive fuel source - Reliability (tides are predictable)-May protect coastline against damage from high storm tides and provide a ready-made road bridge

Cons-Expensive construction needed-Power generated at low demand times-Few good area sites-Barrages may block outlets and affect fish migration

More Renewable Forms

GeothermalPros

-Theoretically inexhaustible energy source-No pollution-Often an excellent supplement to other renewable sources-Does not require structures such as solar panels or windmills to collect the energy--can be directly used to heat or produce electricity (thus very cheap)

Cons-Not available in many locations-Not much power per vent

More Renewable Forms

Recycling

Reusing

Reducing

Energy Conservation

Mathematical Relationships

To determine amount of heat lost or gained

Q = m c ∆T

To determine the amount of heat needed to change the phase of a substance

Q = mHf or Q = mHv

Resources

• http://www.wattsonschools.com/activities.htm

• http://www.sciencenetlinks.com/lessons.cfm?BenchmarkID=8&DocID=14

• http://www.globallearningnj.org/Solar1.htm

• http://www.montanagreenpower.com/index.html