CASA Student Farm solar charging station

CASA Student Farm solar charging station is project made by The Solar Crafters a team of engineers in Cal Poly Humboldt's Introduction to engineering design. Our client for the project is Dr. Renee Byrd who is the head of the new and developing agricultural department for Cal Poly Humboldt. This space is a purchased plot of land that is separate from the university campus but is also located in Arcata. As she is working on the initial startup there are many resources that need to be taken into consideration for the new agricultural space to thrive and to benefit students. Renee has reached out to our ENGR 205 class to focus on the design and processes of creating products in hopes of accumulating these new resources for her vision. Our group, the Solar Crafters were assigned the solar powered charging station via nominal voting.

Our team consisting of Matthew Salazar, Ryan Gardner, Antoni Bak, and Wyatt Zerlang were asked to design and fabricate a charging station that relies on solar energy. The charging station is capable of charging small to medium sized devices intended to benefit the farm and plot of land. The final product is intended to be functionally efficient and completed for Renee Byrd by the end of our fall semester.

The CASA Student Farm currently operates without access to on site electrical power, which creates significant challenges for daily activities and long term development. Students and faculty rely on phones, laptops, and battery powered tools, but there is no way to charge these devices while working at the farm. This limitation affects communication, productivity, and the ability to support more advanced equipment in the future.

To address this need, the project team is creating a modular solar powered charging system that will serve as the farm’s first reliable source of electricity. In its initial stage, the system will provide charging for phones, laptops, and power tools. It is also designed so that additional capacity can be added later as the needs of the farm grow. In the future, it may even support systems such as a greenhouse heater.

The project will be located at the CASA Student Farm in an area that allows for easy access while still receiving sufficient sunlight. The design keeps the physical footprint small so that it does not interfere with nearby student projects or pathways.

This work is taking place with support from Professor Renee Byrd. She is currently transitioning from her position as an English instructor into her new role as the head of the Agriculture Department. Her leadership and vision for expanding agricultural education have played an important role in shaping the goals of this project.

Funding for the initial design began with a budget of four hundred fifty dollars. Additional support was later provided through a school grant to help meet the needs of the farm.

The objective of this project is to provide the Cal Poly Humboldt student farm with a solar charging system capable of charging mobile devices and power tool batteries.

The following are the criteria we looked at when choosing the solutions for this project:

Criterion	Constraint	Weight (0-10 high)
Cost	<$450	8
Charging Time	≤ 1hr	8
Footprint	Has to fit in community center	5
Fire safety	Acceptable Fire safety rating	5
Carbon Footprint	0 Carbon Emissions	8
Electrical Load	Battery dependent (TBD)	10
Sunlight	Amount of PV Depending on Solar Panel (TBD)	10
Maintenance Schedule	Interval between maintenance periods	8
Maintenance Difficulty	Technical knowledge needed for maintenance	4
Modularity	How easy it is to expand. Make it on a larger scale.	2

For our project we had 2 diffrent prototypes. for our first prototype we spent time focusing on how we were going to build the charging station and how we wanted it to look. We started the prototype by designing the box with how we wanted the inside to look and how to make it water proof. We also had the idea of setting the solar panel on 2 posts to save space but that ended up not being feasible for mounting the panel safely and securely.

In the second prototype we focused on how the electrical components were going to be installed in the box. we decided that it would be easiest to mount the panel above the box and run wiring down the post. The wiring then would run into the back of the box and feed the charge controller to the battery to the inverter. During this protype we learned that the project was going to require a charge controller and battery. Originally, we hoped to run the panel right to an inverter but that would provide very inconsistent power and would provide zero power for charging overnight. Thus, we ended up putting in a charge controller and battery so you can always charge as fast as you please and are able to use the charging system overnight.

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Our final PV charging station is going to be able to provide power to the Cal Poly Humboldt student farm for the first time. it will provide power to charge batteries for tools, computer, phones and any other small lithium battery that may need power while at the farm. Our charging station will have one 350 watt solar panel that will feed a 12v 1000 amph battery. This battery will be able to charge around 20 Milwaukee batteries a day or 40 phones/laptops. we also built this project so that it will eventually be able to be added to. our current 4 post set up is ready to accommodate for another panel when the farm is ready to purchase it. as well as it being ready to accommodate for another panel if you set 2 more posts 6 feet to the left of our current posts you will be able to mount 2 more panels. modularity was very important to us in this project and our design offers an option to eventually create an entire solar array for the farm. Our final project offers the first source of power to the farm and will hopefully be the base for building a full carbon neutral power source for the entire farm.

When constructing our charging station, we started by setting our posts to hold the box and our solar panels. We did this by getting 2 12 ft and 2 10-ft 4x4 pressure treated posts. We set these posts 3 ft in the ground with 4 80lb bags of concreate used to secure each post. The posts were 6 ft from each other and 4 ft from the fence. This makes the panel fit perfectly on the posts and the slope in the posts will offer for optimal sunlight.

Once we set the posts, we shifted our focus to building the box to house all of the PV equipment. we made a box out of 3/4" plywood and had a farm made of 2x2 wood. the box is 4 feet call 3 feet wide and 2 feet deep. It has shelves one placed 16 inches up to separate the PV components from the area to charge items. there is another shelve 6 inches above that and one more half shelf that is 6 inches above the shelf below it. the half shelf is ment to store Milwaukee battery chargers as it is cut to fit them perfectly.

After we set the posts and built the box we mounted the box to the post by using 2 2x4 pressure treat boards spanning the back of the posts. this keeps the box off the ground and puts it in an easily accessible place. We also mounted the panel on the left side of the posts so you can add another on the right eventually. We then ran a wire down the side of the post into the box which then hooks up to the charge controler. after the charge controler there is a wire running to the battery to store the power, from that it runs to the inverter which then has wiring coming out the other side. this wire will feed to an outlet on the out side of the box and in the upper side of the box prodviding power anywhere you may need it.

A good way to display a process is by making a video explaining your process. See Template:Video for information on how to add and annotate videos.

The following table lists the materials and components that were purchased in order to fulfill this project along with their supplier, cost per unit, and total cost.

Description of costs, donations, the fact that this is just proposed, etc. For a simple cost table, see Help:Table examples#Cost Table and Template:Bill of materials for two nice formats.

Material	Supplier	Unit cost	Total cost
2, 4x4x10’ PT post	Schmidbauer Lumber	$22.55	$45.10
2, 4x4x12’	Schmidbauer Lumber	$27.07	$54.13
16, 80lbs bags of redimix cement	Schmidbauer Lumber	$8.73	$139.68
Solar Charging Controller	https://a.co/d/9w8Z2gR	$67.15	$67.15
Battery	https://a.co/d/f00X5tI	$119.99	$119.99
1100W Power Inverter	https://a.co/d/2nWu2Eu	$69.99	$69.99
400W Solar Panel	https://conversionstech.com/products/400-watt-solar-panel?variant=40623989948468&country=US&currency=USD&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&srsltid=AfmBOoqyYYLaRa2a53FA_DVrQ9Aa5sqJVWt9On2ot9g7e--VhEE8EDs_yMI	$199.99	$199.99

Operation of the solar powered charing station is very basic, it is meant to be user friendly with low barriers of entry to use.

this project requires very little maintenance. It will be mostly self sufficient only need someone to check on the invertor and battery a few time a year to make sure the system is running at its optimal performance

• when doing maintence you will need a voltage tester and basic electrical tools.
• this should be check every 3 months.
• anyone with a Basic understanding of PV systems and electrical components can do maintenance on the system.

Daily

• No daily maintenance required

Weekly

• No weekly maintenance required

Monthly

• Every 3 months the battery should be check in order to make sure it is floating at a stable charge and make sure that the inverter is still running well (This will be indicated by a red or green light on the inverter)

The solar charging system successfully met the primary goal of providing a reliable source of electricity at the CASA Student Farm. The final design was able to charge phones, laptops, and battery powered tools, demonstrating that the system can support essential operations on site. The modular design also positions the project for future expansion as additional power needs arise. Overall, the project met its intended purpose and provides an important foundation for continued growth of the farm’s infrastructure.

The testing showed that the system functions well for the farm’s current needs but also highlighted areas for improvement. The output was reliable under full sun, but performance dropped noticeably on cloudy days, reinforcing the importance of panel placement and battery sizing.

Maintenance testing indicated that the design is straightforward to service. Components are accessible and use standardized parts, making repairs manageable for future student groups. The modular layout proved beneficial because it allows additional panels or batteries to be added without redesigning the entire system.

During this project we learned how to make a PV system and how to crate power for an area that dosen't already have it.

The next steps for this project is to add panels to the system to provide more power to the farm. the system is ready to take on another panel with the components we provided. If you decide to add more posts to expand the solar array you will need purchase a bigger battery or add another similar battery to the PV system.

This is only how to troubleshoot basic operation. For complex issues, the solution might just say something like contact ________. It should be a table in this format:

Problem	Suggestion
Example issue	Example solution or suggestion
Does not turn on	Make sure it is plugged in
Another issue	Etc.

Introduce team and semester in the following format:

• Antoni Bak
• Ryan Gardner
• Matthew Salazar
• Wyatt Zerlang