Abstract
For the Spring 2015 Engineering 305 class at HSU, the CCAT bike powered tools team's goal is to make a bicycle powered system to provide an outlet primarily for the use of power tools in the CCAT tool shed. Currently, CCAT has to use a few extension cords that draw energy from the grid to run their power tools. Our bicycle power system uses the energy provided by the rider to charge a battery to be used for power tools. Since a human can usually maintain around 100 Watts of power output for around an hour [1], a battery is needed to be able to power tools such as a chop saw that needs between 1400-1800 W of power to run [2]. Other parts necessary for the electrical system include a charge controller, switch, fuse, diode, and inverter. Ultimately, the stationary bike will turn a motor that will charge a battery that will have power tools plugged into an inverter. This bike powered tool station is the most appropriate technology for generating electricity at CCAT. The project will help CCAT achieve net zero energy use by creating renewable energy on site for power tools.
Background
This is an appropriate technology project for Engineering 305 in the Spring Semester 2015. The project's purpose is to design and build a bicycle powered electricity generator to be used for power tools and other appliances at the Campus Center for Appropriate Technology (CCAT) at Humboldt State University in Arcata, California. The students involved are Stephanie Becerra, Alexander Takahashi, and Nathan Braun. The project is set to be completed by May 2015.
Problem Statement
The objective of this project is to develop a way to power tools by using electricity that is generated by off-grid bicycle power. By using off-grid energy, this will be a sustainable way to generate electricity and help CCAT move towards reaching Net Zero.
Criteria
The following criteria will be used to measure the success of this project. These criteria listed below have been chosen based on the collaboration of a CCAT representative and the students of Engineering 305 who are working on the bike powered tools project. The scale (1-10) represents the importance level of meeting the constraint of each listed criteria.
Criteria | Constraints | Weight (1-10) |
---|---|---|
Ease of Use | Must be easy to use with little direction | |
Safety | Must not be hazardous to users or environment | |
Mobility | Must be easy to move for one or two people | |
Life Span | Must be durable | |
Cost | Must be within $600-700 range | |
Educational Aspect | Must include labels for users (something to explain or highlight the benefit or creation of a bike powered tools) | |
Recycled Materials | The structure could include recycled materials, but batteries must be brand new | |
Aesthetics | Must look inviting and professional |
Literature Review
This is a review of the available literature that pertains to the CCAT bike powered tools project.
Appropriate Technology
Appropriate technology (AT) focuses on the design and practical implementation of inexpensive appliances, technologies, and tools of everyday life. [3] It is most definitely a relevant and cost-effective movement. According to an energy fact sheet[4], AT can be summed up as:
- Decentralized
- Technologically sophisticated, though simple in design
- Environmentally friendly
- Deals with social problems
In short, Appropedia defines Appropriate technology as technology that is designed to be "appropriate" to the context of its use. AT is small when possible, requires fewer natural resources and produces less pollution in order to be sustainable.
Renewable Energy
There are many different kinds of renewable energies out there, among the most popular and well know are solar, wind, biomass, biogas, microhydro and nuclear energy. Yet human energy is overlooked. Human kinetic energy can be transfered in multiple ways, it can be used to pedal a bicycle to generate electricity.[5] According to AE News, "Some third world organizations are implementing human powered technologies to generate electricity to power computers and other appliances." [6] In developing countries, if human power was implemented where demands amounted to a average electrical power consumption below 20 Watts per capita it could impact human development directly.[7] Renweable energy is here to stay and it is important to know what energy source would be most appropriate for a location. For CCAT, it would be easy to implement bike powered tools and use human kinetic energy to make it all happen.
Human Power
A Human Powered Energy Generator (HPEG) designed to work with bicycles has been able to produce a maximum current and voltage of 1.4 amps and 215 volts respectively. The HPEG system can also produce 300 W with a rotation speed of 790 rpm. [8]
Bike Power
Examples:
- Pedal-A-Watt Bicycle is a stationary bike power generator that can be used to power lights and small appliances. Any bicycle can be used with the Pedal-a-Watt Stand as long as its in good condition and the wheel is 20 inches or greater.[9] According to AE News, "With the Pedal-A-Watt Stand it takes 15 seconds to drop your bike in and create anywhere from 100 to 300 watts depending on how strong you are." [10]
- UpCycle Eco-charger is a bicycle generator kit that can help turn almost any bike into a pedal generator.[11] A bike attaches right to the sprocket of the UpCycle Eco-Charger and supplies up to 36 Volts of DC electricity. [12]
Reducing Fossil Fuel Dependence
Using human power to pedal a bike to generate power gives you the ability to never be powerless again. To produce electricity without fossil fuels is a great way to respond to climate change. "The generation of electricity produces the largest portion (40%) of U.S. carbon dioxide emissions."[13] There are two ways to reduce the amount of fossil fuels we use: (1) encouraging conservation and efficiency and (2) switching to cleaner and renewable energy sources." [13]
Energy and Power
ENERGY: "The capacity to do work." [14]
- Joules
- kWh
POWER: "Work or energy per unit time."[14]
- Watts
Electricity
"The effect produced by moving charges give rise to what generally is called electricity." [14] AC electricity is the main form of electrical generation, transmission, and distribution. Usually generated at one voltage level, the AC voltage level can easily be changed using transformers. [15] "AC is produced by constantly changing the voltage from positive to negative to positive and so on." [14] AC power is good for running electric motors commonly found in household electronics.
Electrical Components
- Generator: "is a device that converts mechanical energy to electrical energy for use in an external circuit. The source of mechanical energy may vary widely from a hand crank to an internal combustion engine."[16]
- Inverter: "is an electronic device or circuitry that changes direct current (DC) to alternating current (AC).The input voltage, output voltage and frequency, and overall power handling depend on the design of the specific device or circuitry. The inverter does not produce any power; the power is provided by the DC source. A power inverter can be entirely electronic or may be a combination of mechanical effects (such as a rotary apparatus) and electronic circuitry."[17]
- Multimeter: a device used to measure AC or DC voltage and electrical resistance. [18]
- Charge Controller: "is an essential part of nearly all power systems that charge batteries, whether the power source is PV, wind, hydro, fuel, or utility grid. Its purpose is to keep your batteries properly fed and safe for the long term."[19]
For more on information on our specific charge controller click, MPPT Solar Charge Controller Model: CPT-LA05
Batteries
Battery University provides tutorials that evaluate the benefits and constraints of battery chemistries, give advise on choosing the best battery and recommends ways to extend battery life. At Battery University crucial battery knowledge is broken up into three parts to be easily studied. Part One: Basics You Should Know, focuses on addressing battery mechanics, chemistries, charging and discharging techniques. Part Two: The Battery and You, goes into detail about battery personalities and examines ways to get the most out of packs. Priming, storing and recycling is also looked at. Part Three: Batteries as Power Source, considers the battery in portable, stationary and electric powertrains applications. Lastly, there is an inspection on the kinetic power and expense of the battery in contrast to fossil fuel.
Safety
According to Power Generation Inc[20], some easy ways to stay safe while working with electricity include:
- Not using equipment that has been damaged or improperly modified.
- When using cords they should be completely free of damage and/or deterioration.
- When using extension cords make sure to do so properly and temporarily.
- Not unplugging cords by pulling on a wire.
- Not wearing items such as jewelry and watches that might come in contact with exposed, energized parts.
- Always using equipment according to the manufacturer’s specifications.
- Not operating electric tools by touching or standing on a wet surface.
According to NoOutage.com [21], when working with batteries:
- Be sure to read the manufacturer's instructions before using any backup power source.
- Wear eye and clothing protection when working around a lead acid battery and avoid touching eyes.
If the battery acid makes contacts with your skin or clothing, wash immediately with soap and water. If acid gets into your eye, immediately flush eye with running cold water for at least 10 minutes and get medical attention a.s.a.p.
- NEVER smoke or allow a spark or flame near the battery.
- Be extremely careful to reduce the risk of dropping a metal tool onto a battery. It could spark or short circuit a battery or other electrical parts that may result in an explosion.
- Make sure vent caps on batteries are tight.
Also, power inverters contain capacitors and when they are first connected to the DC supply they will draw a high current to charge the capacitors. Yet, this is normal and will usually end in a spark where the last connection is made. Therefore, NoOutage.com recommends that this last connection be made AWAY from the battery. The following sequence accomplishes this:
1) connect the inverter's negative terminal to the battery negative terminal; 2) connect a small gauge temporary insulated jumper wire at least several feet long to the battery positive terminal; 3) touch and hold this wire to the end of the inverter positive cable away from the vicinity of the battery (a spark is normal and indicates the capacitors are charged); 4) remove the temporary wire and connect the positive cable from the inverter to the battery. (No spark should occur if the capacitors are charged.)
This sequence is NOT covered by inverter instruction manuals that NoOutage.com has checked to-date. NoOutage.com advises to be absolutely sure that you have properly identified the positive and negative terminals on the battery. Reversing polarities when connecting the cables may blow the inverter internal fuses and cause permanent damage!
Recycled Materials
This project will be assembled from mostly recycled parts and materials, most of which are already located at CCAT. However, other recycled supplies will be acquired at the following locations:
Construction
To achieve the goal of constructing a bike powered tools station at CCAT a timeline and budget were implemented to ensure the completion of all project activities and to stay within the budget range.
Timeline
In order to complete CCAT's bike powered tools project a timeline was created to meet the deadline completion day of May 8th, 2015.
Date | Objective |
---|---|
March 1 | Budget completion |
March 6 | Complete research |
March 8 | Complete purchasing of materials |
April 18 | Complete testing/begin building process |
April 26 | Turn in document draft |
April 28 | Finish analysis and Appropedia page |
May 8 | Project wrap up and turn in final document |
Costs
The costs from Table 1 are associated with the materials needed to complete the CCAT bike powered tools project. Some materials have already been provided through CCAT free of charge. All other materials will be bought locally and online. Materials will be purchased based on quality but also pricing, as mentioned in the criteria the budget has a constraint of being within the range of 600-700 dollars. As a highly weighed criteria for the project the proposed budget will aim to stay within the client's desired range.
| Table 1. Materials Budget
Quantity | Materials | Source | Cost $/unit | Our Cost $ | Total Cost $: |
---|---|---|---|---|---|
1 | Bike | CCAT donation | 150.00 | 0.00 | 150.00 |
1 | Multi-Meter | Lonny Grafman Donation | 8.00 | 0.00 | 8.00 |
2 | Motor Leads | Hardware Store | 3.00 | 6.00 | 6.00 |
1 | Diodes | Hardware Store | 4.00 | 4.00 | 4.00 |
4 | Battery Leads | Hardware Store | 8.00 | 32.00 | 32.00 |
1 | Battery | CCAT purchase | 100.00 | 0.00 | 100.00 |
1 | Inverter | CCAT donation | 40.00 | 0.00 | 40.00 |
1 | Charge Controller | Online | 44.87 | 44.87 | 44.87 |
1 | Generator | CCAT donation | 100.00 | 0.00 | 100.00 |
1 | Switch | Hardware Store | 7.00 | 7.00 | 7.00 |
2 | Wheels | Hardware Store | 15.00 | 30.00 | 30.00 |
1 | Wires, Connections, Fuses | Hardware Store | 50.00 | 50.00 | 50.00 |
Materials Sub Total= | 173.87 | 571.87 |
Mobile Components
The construction of CCAT's bike powered tools project began with constructing a housing unit for the battery, inverter, and charge controller using mostly recycled materials. The only purchased materials were hinges and wheels.
The inverter went inside the unit.
The charge controller was screwed down onto the lid.
Operation
Maintenance
According "Automotive Electrical Maintenance",[22] All Batteries should be checked at service intervals for:
- Correct clamping and tightening of lugs
- Cleanliness of top, around lugs and connectors
The bike will also need to be checked for rust and corrosion. The wires and connections will also need to be regularly checked and maintained.
Schedule
Instructions
Conclusion
Testing Results
Discussion
Lessons Learned
Next Steps
Trouble Shooting
Team
References
- ↑ (http://www.motherearthnews.com/renewable-energy/pedal-powered-generators-zmaz08onzgoe.aspx)
- ↑ (http://www.donrowe.com/usage-chart-a/259.htm)
- ↑ Daniel M. Kammen - Michael R. Dove - Environment: Science and Policy for Sustainable Development Vol. 39, no. 6 (1997): 10-41
- ↑ http://lsa.colorado.edu/essence/texts/appropriate.htm
- ↑ http://www.alternative-energy-news.info/technology/human-powered/
- ↑ http://www.alternative-energy-news.info/technology/human-powered/
- ↑ Abigail R. Mechtenberg,Kendra Borchers,Emanuel Wokulira Miyingo,Farhan Hormasji,Amirtha Hariharan,John Vianney Makanda,Moses Kizza Musaazi "Human Power (HP) as a Viable Electricity Portfolio Option below 20W/Capita." Energy for Sustainable Development Vol. 16, no. 2 (2012): 125-45. Accessed February 1, 2015. http://www.sciencedirect.com/science/article/pii/S0973082611001116.
- ↑ Hsieh, Ming Chun, and David King Jair. 2014. Design and Realization of a 300 W Human Power Energy Generator System on a Bicycle. Energy and Environment Research. 4, no. 2: 73.
- ↑ http://www.econvergence.net/The-Pedal-A-Watt-Bicycle-Generator-Stand-s/1820.htm
- ↑ http://www.alternative-energy-news.info/pedal-a-watt-stationary-bicycle-generator/
- ↑ http://www.thegreenmicrogym.com/the-story-of-the-upcycle-eco-charger/
- ↑ http://www.thegreenmicrogym.com/the-story-of-the-upcycle-eco-charger/
- ↑ 13.0 13.1 Withgott, Jay, and Scott Brennan. "Global Climate Change." In Environment: The Science Behind the Stories, 504-539. 3rd ed. San Francisco: Pearson Benjamin Cummings, 2008.
- ↑ 14.0 14.1 14.2 14.3 Shipman, James, Jerry Wilson, and Aaron Todd. An Introduction to Physical Science. 12th ed. Boston: Houghton Mifflin Company, 2009.
- ↑ Lynn, Paul A.. Generating Electricity. Electricity from Wave and Tide. 125-183.
- ↑ http://en.wikipedia.org/wiki/Electric_generator
- ↑ http://en.wikipedia.org/wiki/Power_inverter
- ↑ Brittian, L.W. . The Laws That Control and Explain Electricity. Audel Electrical Trades Pocket Manual. 1-9.
- ↑ http://www.wholesalesolar.com/solar-information/charge-controller-article
- ↑ http://powergenerationinc.com/electrical-safety-for-everyday-life/
- ↑ http://www.nooutage.com/Safety.htm
- ↑ Robertson, Stewart. Automotive Electrical Maintenance. London: E. Arnold, 1994.