Research
This page is under construction!!!
Intro
- A research by Beam van Waardenberg into the possibilities for WdKA students to add energy harvesting to their projects. The focus of this research is on how this field of Energy Harvesting can be openend up for WdKA students.
- Beam himself is an e-textile designer: https://myfablab.wordpress.com/
About Energy Harvesting
If your product becomes interactive in any way it needs energy. This energy is normally obtained from the mains (220V) or using batteries. In case of batteries, like laptops and cell phones, the device has to be recharged regularly.
Energy Harvesting means you replace these traditional sources by a way to generate the needed energy by the product you have designed yourself. This can be done by using the energy of the Sun in a solar cell, or wind energy by a generator or the muscle energy of the user by a dynamo.
Research Blog
In this blog the posts document the progress of the research. The research was not a lineair process. The subject of Energy Harvesting is complex and has lot's of details. This research was not only about knowledge gathering but also doing experiments ourselves.
Powerpoints of a course "Energy Harvesting for Designers"
In the "Open AanbodWdKA" a course on this subject was given. Two powerpoints introduce the subject and the calculations:
Categories of Design Projects using Energy Harvesting
- Commercial Projects
- Designers are involved in projects which want to generate commercially exploitable amounts of energy
- Social Projects
- Designers are setting up many local small scale projects for people living in Africa
- Projects creating Toys for awareness
- Designers are creating interesting game situations for children to gain intuition into energy
- Research Projects
- research Designers are investigating possibilities of energy harvesting in clothing and devices and probing the social consequences
Energy Domains
- Very low energy harvesting (Seeback effect, Peltier Element, Piezo energy)
- With this kind of energy you can send a signal once in a while, like temperature, or opening a door by a wireless signal
- Design example: paper generators
- With this kind of energy you can send a signal once in a while, like temperature, or opening a door by a wireless signal
- Middle field, low energy (solar cells, dynamo's for human use)
- In this domain you can charge your cell phones or smaller devices
- design example: Little Sun
- design example: Little Sun
- In this domain you can charge your cell phones or smaller devices
- High (higher) energy projects
- think of the solar panels on a roof, to the big wind turbines
- design example: Roosegaarde bicycle road
- think of the solar panels on a roof, to the big wind turbines
Ways of Energy Harvesting
- Tribo electric, rubbing Teflon etc
- scavenging bio energy, plants
- Cambridge Mosstable: https://biophotovoltaics.wordpress.com/
- Vibrations using piezo elements
- Peltier element using warmth differences
- Solar cells using Sunlight
- dynamo's and muscle energy, like bicycle dynamo's, or dynamo light torches
Calculations, Laws, Formula's
In order to be able to make your project work you need to calculate what energy you need. Then you have to choose from the possibilities avaialable which source will deliver that energy. Also you have to consider the circumstances. You can think the Sun will be able to deliver the energy , but if you will use your design product in Holland the Sun is not always available, so you need to consider alternatives. Power Law: P = V * I, power equals volt times current.
energy Law : E = P * s, total energy is power times the number of seconds you apply this power.
Ohm's Law: V = I * R, Voltage equals Current times resistance.
Example:
Batteries Energy indication: eg 1200 mAh means for one hour (3600 seconds) 1200 mA = 1.2A To know the energy you have to multiply by the Voltage, say this is a 9V battery: P = 9 * 1.2 Joule/second, total energy is E = 9 * 1.2 * 3600 = 38880 J
(You have to calculate in standard units, like A=Ampere, V=Volt, C=Coulomb, then you get J=Joule.)
So the same battery, but running at 1.4V has a total energy of: E = 1.4 * 1.2 * 3600 = 6048 J. Now...these are the calculations, but reality is chemistry inside a battery, so depending on what is inside and the quality, the battery might be able to deliver this energy or less.
If you know the energy in Joule, you can compare:
eg eating a banana means your body gains (on the average banana) 202 kJ.
eg charging my cellphone is 4 hours at 5V with a current of 700 mA, calculating: Energy = 4*3600*5*.7 = 50400 J = 50kJ so with the energy out of a banana I could charge my cell phone 4 times...at the same time delivering the same energy using a dynamo and my muscles for 4 hours (hand crank USB device) is not really comfortable for a human being!
eg a human being of 60 kg running up a flight of stairs, 3 meter high is 1900 J = 2kJ [1] Can you keep running up flights of stairs during 25 * 3.5 seconds = 90 seconds for charging your cell phone? Yes you can, but the dynamo would have an efficiency of 50%, this becomes 180 seconds, 3 minutes...which is still perfectly possible, but slowly you'll get a bit tired of charging your cell phone this way?
Proposed energy installations for the Interaction Stations
- Low energy harvesting kit
- Wuerth kit: http://www.linear.com/solutions/1834
- Use of Wuerth kit: https://www.youtube.com/watch?v=9aSPopIcKLQ
- Telephone charging (fixed) bicycle, an Idea of Otske Penin, student spatial design WdKA
- Wearable: A game between your muscle power and the sun
Technical details
- harvesting chip: LTC3105
- Experimenting with LTC3105 and solar cells
- harvesting chip: LTC3588
- Experimenting with LTC3588 and piezo elements
- Rectifyer bridge
- Experiments with a Chinese Light Torch