Spring Update

Before the fall semester ended, we had planned to implement a fixed angle design with the thin film solar panels donated by Ron. The fixed angle mounting assembly allowed a fixed angle at 32 degrees but there wasn't much functionality to it shown in Figure 1. We had planned to rely on UniStrut or UniRac for the fabrication of the frame to hold the Solar Panels. It turned out that they do not make frames for the thin film solar panels we use. In addition, the mounting assembly would be too heavy for the track post.


Figure 1. Fixed Angle Solar Panels.

This was a huge problem for our team so we resulted in creating our own frames out of wood shown in Figure 2.

Figure 2. Wooden Frame Panels

Instead of the fixed angle mounting assembly, we transitioned to an adjustable angle version. The objective of these designs was to allow the solar panels to move at any variable angle desired. From the fall semester, we concluded the maximum effective angle are from 30 to 60 degrees. This made an adjustable angle design was much more favorable for Maker's Faire. My team came up with two other designs with different variations. Either design can be slotted or make use of pin holes. There are pros and cons for each variation. The slotted variation allows better selection of angles but when the difficulty of fabrication is high. The other variation is the use of pin holes. When fabricating, accuracy is important and without making the use of the waterjet cutting machine, this wouldn't be possible. Figure 3 and Figure 4 shows the different variations of the first design. Using bolts, it will help ensure it to our desired angle. The first design required a lot of accuracy in fabrication due to the addition of the mounting cap.  


Figure 3. Slotted Circular Design

Figure 4. Pin holed Circular Design.

Our second design is a three bar mounting assembly shown in Figure 5. This can also be slotted if needed as shown in Figure 3.

Figure 5. 3 Bar Mounting Assembly.

Mid-Spring Semester, we decided to fabricate the second design due to the simplicity of fabrication and in-house materials. Most of the materials use are going to be aluminum as they are lighter than steel. Using three pieces of aluminum, they are welded together and to be bolted on with the steel plate underneath shown in Figure 6. Underneath the steel, there is a five-inch rectangular tubing that serves as a mounting cap to the track post. With the amount of the weight of the solar panel frame and the 3 bar mounting assembly, my team believes that it will help stabilize the movement from the track post.

Figure 6. Bottom of the mounting assembly.

In Figure 7. shows how the entire the track will look once fabrication is done.

Figure 7. Projected completion.

Project Update

Since last meeting on September 30th, 2015, as part of the small scale solar team, my team and I have been trying to find solutions of powering the small scale model. We had meetings with the other small scale teams to try to find ways around the problem last year's group had. Working with other groups, the plan is to have 10 model sized bogies running and around 4 stations. Each bogie is estimated to run at least 2 to 3 amps, so in total of a maximum amps of 30 amps might be needed for the track. For each station we were planning to implementing a dual axis solar tracker but until the track is fully finalized, the plan is to only power one station and one segment of the track.  

 From the research done before, we know that the single axis small solar tracker would not work. The solar panel itself is too small and will not harvest enough energy to power one modeled size bogie. The whole small scale team thought it would be fine to have a solar farm providing at least 22 amps and the rest through batteries. The idea of solar farm was brought up because since this is small scale model, installing solar panels onto model stations will not be able to collect enough energy. This can only be implemented on the intermediate or the full scale stations. A dual axis may also be implemented on the bogie too, but my team has not discussed this problem with the other part of the solar team yet. 

Project Update

Since last update, my sub-group of the solar team have decided on a partial solarized system for the 1/12th scale model. The system will be solarized with external batteries attached to power the model bogie. We concluded that we can't fully solarize the model because the conditions of trying to run the bogie 24 hours, 7 days a week. The solar panel provided by Miasole is not sufficient to supply enough energy. If we have more solar panels from Miasole, I think the model bogie will deplete more energy than it is receiving. 

The highest efficiency for a high commercial grade solar panel is only 20%. An alternate solution is to have many of these surrounding the tracks and have a energy storage device. The solar panels can slowly harvest energy while the bogie is not running.

Talking to Ron Swenson before I left, he told me that it is possible to fully solarize the system and gave me a spreadsheet on his calculations. 

SOLAR PANEL

The last meeting on September 9th 2015, the topic of placement came up. Placement on the bogie is a huge issue because the lack efficiency in solar panels. Even with maximum exposure of the sun, the solar panels on the bogie are inefficient. From my last post, the highest efficiency a commercial grade solar panel can receive is up to 20%. A possible solution was brought up involving cylindrical solar panels that are able to save more space and absorb more. I find this solution more feasible towards placement but it does not solve the inefficiency of the solar panels. The problem is that the solar panel technology is not advance to provide enough efficiency without jeopardizing space allocated for placement.

You can interrelate this problem to the history of processors. In the semiconductor field for processors, engineers and physicist follow Moore's law. Moore's law is a guide to long term planning and target development. Intel executive David House, predicted the chip performance would double every 18 months due to the combination effect of more transistors. Currently, the rise of transistors and speed of processors have grown exponentially and will continue to grow. I believe the same can be achieved in solar panel technology.

Having to be part of the 1/12th power team, I believe an alternate solution for solar harvesting is from a electrical charge station for the bogie. On the 1/12 scale, there will be a charging block at a station and it will be connected to multiple solar panels. The solar panels will be able to charge the battery pack that is already implemented on the current design.

The drawing is just a simple ideal sketch of how the charging block will be connected.  

SOLAR PANEL RESEARCH

This Automated Transit Network (ATN ) is unique compared to the others because the plan is to implement solar power. As of right now I do not believe a fully solar powered ATN is possible. Today the only fully solar powered building or a vehicle out in the market is a zero net energy building. 

A zero net energy building are buildings that produce energy as much as they can consume. During the day, the zero net energy houses harvest as much energy as it can and then send excess energy to the grid. During the night, if energy needs to be used, it will use the energy that was harvested during the day. 

With the constant use of the Superway, there is no time to recharge the grid or power it 24 hours, 7 days a week. The Superway can be powered half by solar and half by electricity but just not fully for the time being. Reading upon 2014-2015 group report, the commercial solar panels sponsored by Miasole, the solar panels are only 17% efficient. The standard solar panels range around 15% efficiently while higher grade range around 20%.  

The picture above is the solar panel, last year's group was trying to implement. The small scale solar panel that draws only 17% of energy is not enough to power the tracks. According to comments from engineers, lab grade solar panels can absorb up to 40-50% which can make a huge difference for our model scale. 

According to ABC news, there is a new discovery made with solar panels. There is an "absolute black" solar panel that is able to absorb 96% of light. There are many new discoveries still to be found. If this "absolute black" solar panel can be commercialized soon, this model and the full scale prototype can make this fully solar powered ATN possible.  

References:

https://www.inist.org/library/2015-05-21.Ornellas%20et%20al.Spartan%20Superway%202014-2015%20Final%20Report.SJSU%20ME195.pdf

http://miasole.com/en/miasole-advantages/flexible-solar-cell/

http://www.greenhomebuildermag.com/spring-11-44.php

https://www.reddit.com/r/askscience/comments/1qgvs4/how_much_energy_is_lost_from_reflection_on_solar/

http://abcnews.go.com/blogs/technology/2012/03/absolute-black-solar-panels-absorb-almost-all-sunlight/

http://www.sunedison.com/home-solar-systems/blog/net-zero-energy-homes

http://www.zerohomes.org/zero-energy-homes/

http://solarenergy-usa.com/solar-info/solar-and-electric-vehicles/

MEETING SEPTEMBER 2, 2015

The meeting on September 2, 2015, started off with introducing mentors and previous members of the team that will help and do their best to contribute more this year. Everyone part of this team started out presenting findings that have sparked their interest in this project. There were many things said about what they have learned and what they hope to bring this year. This research was intended for members to discover their interest and hope to choose a part where they fit comfortably. After presentations, I announced an upcoming event on Saturday, September 19th. September 19th is the 43rd Annual Silicon Valley Electric Vehicle Rally & Drive Electric Week where we will present the model size superway. Once the announcement is done, Ron Swenson and the previous team help give a brief tour around the building to show what has been done and needs to be done.

After the team broke into the areas where they see fit. Within the areas, we broke into sub groups that are responsible for different parts. I went to the 12th scale model and the subgroups were created involving control systems, solar panel, the design of the model, and few more. Out of the sub groups, I decided to join the solar panel group because that's where my interest lies. There is much needed improvement for the model scaled solar panel system. According to Dr. Furman, the summer group tried but did not complete a working solar panel system. I am also thinking about joining another sub group to work on the cabin design.

In my subgroup, I got a chance to talk to Ernest, who was part of the summer team. He mentioned how the Korea team neatly organized the board and the model bogie system but not so much on the solar panels. Professor Burlingame added that there is no possible way the small size solar panel can absorb much to power the model scale. With that information, it puts into perspective on how much solar panels we need to power the model and what can be worked around it. During my time of a short brainstorming, I was thinking about a mini station where it can charge the model bogie while the other one is moving. The goal is to have more than two model sized bogies in order to implement the safety measures we are aiming for. Within my subgroup, there wasn't much brainstorming with each other yet but I do plan on brainstorming better ideas next meeting.

INTRODUCTION

My name is Allan Wai, and I am in my senior year at San Jose State University pursing my BSME degree in Mechatronics. My interest for Mechatronics spawns from robotics and automation control. For my senior project, I decided to join the Spartan Superway team to try to implement solar power to the model superway. Using the leadership skills I have gained from my job experiences, I plan to coordinate events for the team. I also am looking forward to work with my team and build upon last year's previous work to reach our goal. Aside from my studies, I try to find time to enjoy on my riding or fixing my motorcycle.