Summary And Applications

In this experiment you were introduced to a modern marvel called a solar cell that produces electricity directly from sunlight. Solar cells, like the batteries you studied in Experiment 1, can be placed in series or parallel with the same voltage and current results. That is, solar cells in series add the voltages of all the cells while the total current remains at that produced by a single cell. Conversely, solar cells in parallel add the currents produced by all cells with the total voltage...

Activity Replaying The Charge Cycle

This activity involves replaying the charge cycle in a rapid, fast forward manner. Recall from Exp_1_Charge that it took nearly 4 hours to charge the batteries and that during this time, we also took a 64-second average of the Battery Charge Current (BCI) and Battery Charge Voltage (BVI) and stored these values in EEPROM. As a matter of fact, we stored exactly 200 samples, each, of BCI and BVI in EEPROM. This is because DataPtrMax is limited to 400, so 400 divided by 2 samples EEPROM entry 200...

Appendix B Source Code Listing

----- For Experiment 2 Dueling Solar Cells Left Solar Panel LED on P9 Right Solar Panel LED on P8 Value proportional to A D voltage resolution of 0.02 volts bit. Example offSet 10x0.02V 0.20V For Experiment 3 Solar Cell Sun Tracker Sun tracker servo on P12 Dampens servo's hunting initial value of waitCount ----- For Experiment 4 Half and Full Wave Rectification ---------------- sampleCount VAR waitCount 'Nib ' Number of A D samples per period sampleArray VAR Byte(10) ' 10-element array for A D...

Native American Wind Farms

The Rosebud Sioux Tribe Wind Turbine Project is the first large-scale Native American-owned and operated wind turbine in the country. The Rosebud Sioux Tribe Wind Turbine Project Photo courtesy of the Intertribal Council On Utility Policy The Rosebud Sioux Tribe Wind Turbine Project Photo courtesy of the Intertribal Council On Utility Policy Located on the Rosebud Sioux reservation in south-central South Dakota, the project had been stalled for over a year as funding and energy sales issues...

Wind Farms as a Tourist Attraction

Windmill Tours of Palm Springs, California has hit upon a unique and fun way to learn about wind power. As the ad says Travel through a forest of towering windmills on electric-powered vehicles. Feel the energy as the giant blades WHOOSH overhead. Your skilled guide will take you inside this working wind farm comprised of turbines modernized to efficiently contribute to a cleaner and safer environment. As you travel along the 90-minute adventure, you realize the environmentally friendly power...

Wind Farms At Sea Denmark

In the summer months of 2002 the world's largest offshore wind farm on the Danish west coast was built and put into operation. The sea-based wind farm is sited 14 to 20 kilometers into the North Sea, west of Blavands Huk, and represents the first phase of a large-scale Danish effort to produce non-polluting electricity from these offshore wind turbines. The Horns Rev project, as it is called, has a total capacity of 4000 megawatts and must be established in full before 2030. Figure 6-33 The...

Activity Programming The Battery Charger

With the circuit built it's now time to program the BASIC Stamp module for this application. As before, let's start with updating the program name and declaring the variables. You may enter the program by typing in the code shown below, or you may download it from the Experiments with Renewable Energy product page at www.parallax.com. V In the BASIC Stamp Editor, open ADCTest.bs2 V Select File, then Save as rename the program BatteryCharger.bs2 V Update the title to read as follows '...

Activity Discharging The Batteries

The first thing we'll do is discharge the batteries. If your batteries are brand new, from the kit, and have never been charged before, then they will probably discharge quite quickly. The small DC motor with the propeller will act as a load for the batteries. As the fan runs and the batteries discharge, we'll plot the batteries' voltage using StampPlot. Furthermore, let's time how long it takes for the batteries to discharge. V Connect power to your board, and look at your watch and note the...

Calculating Power Output with a Load

The internal resistance of the source (our alternator) must be taken into effect to calculate power output with a load. The key difference between the Wye and the Delta arrangements lies in the total resistance of the coil arrangement. The total resistance of the Wye arrangement is three times as large as the total resistance of the Delta arrangement Rotational speed of magnets 1200 RPM voltage of one phase Ecoii 3 volts Load a 1.2 volt rechargeable battery RtotalWye 15 ohms RtotalDelta 5 ohms...

Parts Required

(1) A D Converter circuit from Chapter 1, from Figure 1-6 and Figure 1-7 (1) 1 kQ resistor (brown black red) (1) AAA Battery Holder (red wire is +, black wire is -) (2) 1.2-volt AAA NiCad rechargeable batteries (included) V Disconnect power to your BASIC Stamp. V Insert the AAA batteries into the battery holder. V Add the 1 kQ resistor and battery holder to the circuit shown in Figure 2-1 and Figure 2-2. This is the same basic circuit we used in the last chapter here, we'll use it to read the...

Wind Farms

There are many today who think of harvesting the wind as if it were a crop. In reality, wind is a like a crop since it has value to the wind farmer who cultivates it as well as to the consumer this is serviced he services with the electricity the wind farm generates. Unlike editable crops, however, the wind crop does not need to be tilled, fertilized or spayed with pesticide to grow healthy and strong. At the same time there is inherent risk in establishing and maintaining an economically...

Generating Electricity Using Wind Power

Experiment 5 examined the fundamentals of three-phase power. The information presented here deals with a principal application of this technology, namely wind power. Figure 6-26 Power-generating Windmills Figure 6-26 Power-generating Windmills Using the wind to generate clean, efficient and cheap electricity has been the dream of many people and industries for at least 100 years. However, until very recently the ability to achieve these three goals was elusive, mainly because fossil fuels were...

Creating Three Phase Power

It turns out that creating three-phase power occurs quite naturally from geometry. With that in mind, take a look at the physical layout of the coils and magnets in our wind turbine, shown again in Figure 6-3. The turbine's black rotor disk has six magnets that are physically arranged 60 degrees apart from one another, and the north-south orientation of the poles alternates from one magnet to the next. Inside the base, or stator, of the turbine are three coils of wire. In the schematic in...

Real World Suntracking Solar Arrays

While this is certainly a specialty area related to solar arrays, sun tracking systems do represent a significant investment in engineering and cost. The intended return of more consistent electrical power during daylight hours as compared with a fixed solar array must be worthwhile. Like their solar cell counterpart, sun tracking system's initial development dates back to the 1950s where satellites needed to keep their solar panels pointed at the sun while they orbited the earth. It was only...

Activity Charging The Batteries

In this experiment, we'll be charging our two AAA NiCad batteries. The battery's fully charged operating voltage is 2.4 volts when the two batteries are connected in series. The key word here is operating, since this is the voltage that the batteries should be at immediately after a full charge to provide power to a load. In this case our load is a small DC motor-fan. The purpose of our battery charger circuit and PBASIC program is to charge the batteries until they are at full capacity, which...

Wind Energy Technologies

While old-fashioned windmills are still seen in many rural areas for pumping water, modern wind turbines are divided into two major categories horizontal axis turbines and vertical axis turbines. Producing 204 megawatts, this is the third largest wind power plant in the world. Photo by Michael McDiarmid, Courtesy of New Mexico Energy Conservation and Management Division The New Mexico Wind Energy Center has 136 turbines, 320 feet high. Producing 204 megawatts, this is the third largest wind...

Activity Building The Dueling Solar Cells

Adc0834 Wiring

We named this experiment Dueling Solar Cells since we will use two separate, but equivalent, solar panels to measure and compare their individual voltage outputs. We will be removing the Battery Charger circuit, and adding the solar cells and two indicator LEDs to our Analog to Digital Converter circuit. 1 Solar Cell Assembly from the Solar Kit 8 solar cells 1 plastic tray 7 spanner bars 16 lock washers 16 nuts 3 30 jumper wires, each with 1 tinned lead The Solar Kit comes with solar cells that...

Activity Programming The Half Wave Rectifier

Once again, we will be building upon our previous program. These additions let us read and compare the voltages generated by the two solar arrays. Remember, if you don't want to modify and update your program as shown here, you may download all of the source code for this text from www.parallax.com. V In the BASIC Stamp Editor, open DuelingSolarCells.bs2. V Rename and save the program as Half-FullWaveRectifier.bs2. V Update the title to read as follows Experiments with Renewable Energy v1.0 -...

Requirement Of Circuit Of Rechargeable

Rechargeable Fan Circuit Diagram

2 2N3904 transistors 1 Red LED 1 Yellow LED 3 470 Q resistors 1 1N4148 diode 1 AAA Battery Holder red wire is , black wire is - 2 1.2-volt AAA NiCad rechargeable batteries included 1 DC fan assembly from the Solar Kit 1 DC motor 1 stand base 1 stand post 1 stand loop 1 screw 1 hex nut 1 2-wire lead with connectors Electrical tape not included V Assemble the DC fan motor, propeller, and stand, following the direction in the Solar Kit. V Connect the wire leads to the back of the fan motor with...

Activity How The Sun Tracker Works

Finally, if the left panel's voltage is greater than the right panel, the program branches to Exp_3_Move_Right. Following these basic branch instructions, the remaining part of the code does the actual tracking work. At Exp_3_stop the program executes a pulsout command to the servo for 750 two-microsecond units, or 1.5 milliseconds. This value should stop the servo. If it doesn't and the servo still creeps a bit to the left or right, you can point the solar panels directly at your light source,...

Chapter Experiment Programmable Battery Charger

Experiment 1 begins this Experiments with Renewable Energy course with an interesting and practical project that is, building a programmable battery charger. Battery chargers have been around ever since rechargeable batteries were invented. So what's so interesting about charging batteries Actually quite a bit, since battery charging is really a combination of half art and half science, and there seems to be no end to the variety and complexity of battery charging circuits and techniques. The...

Activity Programming The Dueling Solar Cells

We will be building upon our previous program, since every experiment uses the Plot_It subroutine. These additions let us read and compare the voltages generated by the two solar arrays. You can either download DuelingSolarCells.bs2 from www.parallax.com, or you can update your current program by following the steps below. V In the BASIC Stamp Editor, open BatteryCharger.bs2. V Rename and save the program as DuelingSolarCells.bs2 V Update the title to read as follows Experiments with Renewable...

Appendix A LearnOnLines REEL Power Project

Figure A-1 A 21st Century Learning and Teaching Project sponsored by LearnOnLine, Inc. LearnOnLine's REEL Power Project, which stands for Renewable Energy Education Lab, is the inspiration for this course on energy. REEL Power is designed to help students understand and apply the math and science they are studying by means of a motivationally enhancing make that fun filled renewable energy project. REEL Power is both classroom-based and Internet-based and makes excellent use of both these local...

Activity Shielding The Solar Panels

Hooded Figure Side View

This experiment uses the same circuits from the previous experiments to read the solar panel voltages. A cardboard hood and a servo will be added to the solar panels, and the servo will be connected to the board. You will also need the following household or school-room items that are not included in the kit Cardboard box or sheet of heavy paper for a hood Before mounting the solar panel to the servo it will first be necessary to add a box-like hood around the solar cells. The reason for this...

Activity Programming The Sun Tracker

Once again, we will be building upon our previous program. These additions let us read and compare the voltages generated by the two solar arrays. Remember, you may either follow the directions to build on your program for each experiment, or download the programs from www.parallax.com. V In the BASIC Stamp Editor, open DuelingSolarCells.bs2. V Rename and save the program as SunTracker.bs2. V Update the title to read as follows ' Experiments with Renewable Energy v1.0 - SunTracker.bs2 ' Tracks...

Activity Assembling The Threephase Ac Alternator

The three-phase AC alternator kit is used to generate the AC voltage for the half wave and full wave rectifier circuits. While we could have supplied you with a simple wall transformer that converts 110 VAC to a much lower voltage like 10 VAC, that would not have been as much fun. Instead, we chose to supply you with a miniature wind-powered AC alternator that will be both fun to build as well as fun to use. Plus, you will use it in the next experiment to demonstrate how three-phase power is...

Activity How The Half Wave Rectifier Program Works

Remember our floor and superstructure analogy from the earlier part of this manual. Well, by commenting out these calls, what we've done is sealed off the first three floors of our software building while we work on the final two floors, just as we sealed off the Battery Charger experiment on the first floor while we worked with the solar cells. Also notice how simple, yet elegant, this is. By just a single comment in each call to Exp_1, Exp_2 and Exp_3 we have effectively disabled their...

Activity Building The Full Wave Rectifier Circuit

Full Wave Rectified Signal Oscilloscope

Now it's time to build the full wave rectifier circuit. To do so you will need all the components you used in the half wave rectifier circuit plus The schematic is shown in Figure 5-22. The parts placement should look like that in Figure 5-23. Examine how the four diodes are inserted into the breadboard. V Disconnect power to your board. V Remove the 1000 F capacitor for the time being. V Add the diodes to the circuit, being careful to observe the directions of the diodes' anodes and cathodes....

Rectifying Three Phase Power

Our wind turbine produces three phase alternating current AC , which we'd like to rectify to direct current DC . Recall the bridge rectifier circuit of Chapter 4, which used 4 diodes. In the bridge circuit, two diodes were active during the positive part of the waveform, and the other two diodes during the negative part. By adding two more diodes, this circuit can be expanded to rectify all three phases from our wind turbine. With 6 diodes, the three-phase rectifier can rectify all three...

Wiring the Wye Coils

For our wind turbine, we will use the Wye coil arrangement. Each set of coils is color-coded by two wires of similar coloring, as shown in the table below. The colors are shown in the schematic in Figure 6-6. Pay particular attention to the blue and blue-white wire placement. This is not a mistake. It is necessary to flip the source-return orientation of this coil relative to the other two coils to achieve the proper three-phase operation.

Activity Building The Half Wave Rectifier

Schematic Half Wave Converter

With the three-phase AC alternator assembled, it's time to construct the half wave rectifier circuit on your Board's prototyping area. You can remove all but the A D Converter circuit from the breadboard area since we are done with the DC portion of our experiments. This experiment uses the A D converter, and adds to it 1 Assembled wind turbine three-phase, wind driven AC alternator 1 Table fan not supplied Wire strippers not supplied V Remove all but the A D Converter Circuit from your...

Activity Adding The Servo To The Solar Panels Parts Required

Solar Energy Parts List Pictures

1 Parallax Continuous Rotation servo 1 1 hexagonal standoff, pre-drilled 1 1 4 panhead Phillips screw 2 7 8 panhead Phillips screws 2 4 hex nuts Parallax screwdriver Hand drill with a 36 bit -OR- Hobby knife such as an X-acto knife with a slim, sharp tip Optional Diagonal cutters or other flush clippers such as toenail clippers Below are the directions for mounting the servo on the solar panel tray, as shown in Figure 4-13 and Figure 4-14. V Unscrew the servo horn from the servo, being careful...

Stamp Plot Software

Before going too much further it would be best to concentrate on the StampPlot Pro graphical plotting software that will add a tremendous visual aid to the experiments. We will be using the StampPlot Pro version with the Free Home Educational Standard License. Developed by two professors, Martin Hebel and Will Devenport at Southern Illinois University, the StampPlot graphic plotting software brings the voltages produced in the experiments alive Figure 1-1 shows just one example of a single...

How the AD Converter Routine Works

This routine references names aliases defined in the Declarations section. The first four pin directives give names to the BASIC Stamp I O pins that identify which pin of the ADC0834 they are connected to. These aliases will be used in commands that enable communication between the two devices. A2dChipSel A2dDataIn A2dClk A2dDataOut The four con directives that follow are specially coded to let the ADC0834 know which channel, 0 through 3, that we want to convert. One of the first things the...

The Experiments with Renewable Energy Parts and Text

Similar to most Stamps in Class Student Guides, you need a BASIC Stamp 2 module with a Board of Education carrier board and the Parts Kit. The content of the Experiments with Renewable Energy Parts Kit is listed below. These replacement parts are available from Parallax but may also be sourced from common electronic suppliers. In an effort to provide the best quality and most up-to-date products for our customers, you may find that some of the actual parts received with this kit may differ from...