From the time you wake up in the morning to when you eat, walk, even sit at a desk, you have the potential to generate electricity. What if we could harness and harvest our actions, turn our comings and goings into a usable renewable energy source? In my thesis, I explore the potential that mundane actions have to produce the electricity for the low power devices that supplement our lifestyles. My first instantiation of this idea is focused on doors. In an office building of just 3,000 workers (like Tisch) entry doors are opened at least 4 times a day per person , 12,000 times. I have created a prototype, which is an add-on for hinged doors that generates electricity each time a door is opened and closed. There is a circuit to store this electricity, measure what it produces and stores over time, save that data on a database and have it dynamically graph and monitor its progress on a website. The stored electricity can be used for any of the buildings off grid needs, such as emergency signage, security cameras or lighting.
The inDOOR Energy Harvester went through several iterations before arriving at its present form. The object was to couple a low profile, aesthetically pleasing mechanism and housing that would produce the maximum number of rotations on the shaft of the generator from linear motion. Extensive testing went into what type of generator to use as well as storage devices. Various AC and DC gear motors were tested along side stepper motors, piezo generators and linear arrays of magnets and coils. These were attached to the same door for a period of 3 weeks in a high traffic area on the fourth floor of the Tisch building at New York University, while the stored energy of each was data logged and graphed. The final design is fairly simple with few moving parts and therefore robust and reliable. From the results of the previous testing, the final design contains a dual output AC/DC geared generator attached to a stainless steel industrial linear motion guide block and track. An arm extending from a bracket mounted to the wall adjacent to the door attaches to the generator mount with a clevis end. As the door opens and closes, the arm pushes and pulls the generator along a gear rack, which turns the pinion gear on the generator and moves a set of magnets through coils inside the generator approximately 110 revolutions per swing. The induced electricity is then rectified to DC and stored in a 2 Farad 5.5volt super capacitor. Unlike Battery Storage, capacitors have very high instantaneous charge and discharge rates, are efficient at capturing large amounts of energy as well as having very high life cycles. Though battery energy density is far high than capacitors, manufacturing and disposing of exotic batteries causes more pollution than they could prevent.
The second aspect of the system is the data-logging and monitoring capabilities that provide information and motivation for the user. Each time the door is opened and closed a circuit is activated by a switch. This triggers an Arduino stamp micro-controller to measure the current energy storage of the capacitor each time the switch is connected and counts the number of times the door opens. The micro-controller is then able to call an http request via a Lantronics Ethernet port (also available as a wireless unit), connected to the Internet. The data collected is then passed to a php script, which in turn inserts it into a server side database with a time stamp. The whole transaction happens in a single second; therefore the resolution of data collected can be controlled and saved to study at a later date.
The third aspect of the system is the dashboard visualization, which provides available information for user feedback and system monitoring. This single web page can be viewed anytime, anywhere. The large, colorful, dynamically generated graphs and charts give the user a quick read of the most current energy stored as well as energy generated over time. A simple mouse over a window gives specific information about each intersection of the graph, such as watts at a given time. A mouse over any technical term or concept, such as watt or joule, provides a brief explanation of the term and a link to an external in-depth site for further explanation. A drop down menu then allows the viewer to drill down deeper into data and value conversions about the indoor Energy Harvesters functioning. For example, clicking on the category electricity produced then allows the user to look at usage from the past day, week, month or year. Clicking on carbon saved would then depict a graph with the amount of carbon dioxide it would have taken to produce this electrical energy viewable over he same time options, as well as sulphur saved and money saved. The scalability of the dashboard functions as a learning tool for the casual viewer as well as for those interested in-depth analysis. If a building had several indoor Energy Harvesting modules attached to the doors of its high traffic areas, then an easy comparison could be made between the various modules, e.g. which doors produce more than others. In addition, charts may be set as screen savers or desktop backgrounds to show, for example, how much has been offset from the buildings total usage that day or equating what was produced was enough to run your computer for 7 hours. The monitoring system also allows one to track if there are any problems or upgrades.
Lastly, the end application for the energy generated from the indoor Energy Harvester is focused primarily on off-grid needs. The energy harvester can therefore support the needs of the door and the area surround it, such as emergency exit signage, lighting, security cameras or sensors. As mentioned above, technology is now able to run on less and less power, and battery and storage capacities can hold more energy at a smaller size and lighter weight. Thus, more devices can be powered from the motion of doors. Charged during the day from people moving in and out of an office building, signage may illuminate at night cost free to the building and the environment.
The inDOOR Energy Harvesting system (iEH system) functions as a product service system in which the mechanism and the service are a closed loop. One leases a service in which the mechanism is part and parcel. Custom LED displays and lighting for the system will be available as well, depending on the buildingsÕ energy needs. Upgrades and repairs will be covered as part of the service cost. Thereby, fabrication, sales, monitoring and eventual recycling of the parts towards new modules would be guaranteed. The energy cost in producing the modules must therefore be outpaced by what the module can produce over its life span.
for more information about this project and all documentation of its development please visit my Blog
This system is currently in the prototyping and testing phase.
design and concept by Raphael Zollinger
contact: rz403 at nyu dot edu
The inDOOR Energy Harvester is a low cost, low profile mechanism that converts rotational kinetic energy from opening and closing a door to usable electricity.
It contains a circuit to store this electricity, measure what is produced and dynamically graph and monitor its progress from a website.
The stored electricity can then be used for any of the buildings off grid needs, such as emergency sign-age, cameras or lighting.
The inDOOR Energy Harvester is a part of the unconscious power plant project, which seeks to bring awareness to the potential for energy generation and usage as a part of daily routine.
If we start looking at doors as a source to contribute a small slice of the energy we consume everyday, then eventually the rest of our actions and environment becomes possible too.
