This summer, I had the opportunity during my internship with Design Collaborative to research a topic of my choosing. I had a tough time trying to figure out what I wanted to research. I then landed on the topic of alternate sources of energy. When I first entered college, I was interested in different sources of energy. Alternate sources of energy like wind, hydro, and solar power had appealed to me, but I never had the time to get to delve into this topic more. So, when I realized that I had an opportunity to get to research in the area of solar, I was excited and interested. But I didn’t have an idea on how to proceed with the research. I approached Phillip Oprie, an electrical engineer at DC. He and I brainstormed about what to do, and we came up with the idea for me to use a solar program called System Advisor Model (SAM) on an existing project to show how solar power can offset power in a building. With a goal in mind, I set off gathering information and preparing my presentation.
The first step was to find a project to use as an example of what solar power could generate. On the workplace team, we have a data spreadsheet of several different project types. Our spreadsheets include projects from headquarters, offices, bank branches, and other miscellaneous projects. Each project type is broken up into square footage, total power, and power per area. These values allowed me to figure out the size of the building, the total amount of energy required to fully power everything in the building, and how much energy there would be per square foot in the building.
With these values present, I began using the DC database to find footprints for the different projects. I was looking for a large flat area on the roof that would be the location for solar panels. After some searching, I found a good project to apply my research to; ORNL Federal Credit Union in Knoxville, Tennessee. The project was a 24,100 square foot building with a total power requirement of 389.31 kilowatts. I chose this project because of the fact that there was a nice open space on the roof where the mechanical equipment was all sectioned off with mechanical screening. After picking this project, I began measuring the area that the solar panels would go into. I dug through several different mechanical and architectural plans until I found the total area I had to work with, which was a little over 3,700 square feet. With all this information gathered, I moved on to using the solar program, SAM.
The SAM program was one of the tools Phillip gave to help me out with the research project. The SAM program is a solar prediction program that allows the user to estimate how much energy the solar panels would be generating, the savings, and a rough payback period. The program does this through a couple of different settings. There are two modeling methods to use.
The Detailed PV Model is the more elaborate and complicated of the two methods, allowing for the user to manually select the specific panel and inverter manufacturers to better suit the project. The PVWatts model is a simpler method that allows the user to focus more on other details the program offers while still providing fairly accurate data.
I chose the PVWatts model for my research to simplify things on my end of the project. I did use the Detailed PV Model to select a solar panel to base the data on for both my project and the spreadsheet that I had made. I was able to select the regional weather, angle of the solar panels, and enter in a rough estimate of energy consumed by the building. I simulated the results, and it appeared that the solar panels, which covered roughly an eighth of the building footprint, were generating about a seventh of the total power consumed, with a payback period of a little shy of 16.5 years. Curious, I wondered how the payback period and energy would change if the solar panels were close to net-zero, where the building doesn’t draw or deposit energy into the power grid. The results from that were that the energy generated was very close to net-zero, and the payback period didn’t increase by that much. The only thing that would increase would be the price for the panel layout, which may turn people away from the purchase. In my presentation, I provided a metric table and the monthly energy and load to compare. It allowed me to show the company what the SAM program can do by using an existing project.
There was additional information that I had gathered aside from the project information and data from the SAM program. When I was researching solar panels, there are often different snags that get in the way. One of the snags was the integration of solar. Solar requires enough space to be able to generate that amount of power, and sometimes the area provided is not big enough. I researched different methods of how to integrate solar into different projects. One method was integrating them into carport roofing. By using the panels as the roof for the carports, it would have a dual purpose. This integration can have an optimal angle to generate energy, while also providing shade and protection for the cars parked beneath. Another method was to replace mechanical screening with panels. Phillip mentioned to me that mechanical equipment is often fenced off. Solar panels can help screen the mechanical equipment while also generating energy, giving the screening multiple purposes like the carport roofs.
Aside from finding integration methods, I also created a spreadsheet for the company to use. I created a spreadsheet that allows the company to find annual energy produced in the Midwest and Southeast and the footprint of the solar panel. All that is needed to use the spreadsheet are average watts per square foot and the footprint of the building. The watts per square foot are put into the spreadsheet to populate the spreadsheet with constants. These constants are multiplied by the footprint of the building to find annual energy produced and the area required for the solar panels. I hope to populate this spreadsheet with more data so that the company could use this to help with future projects.
This research project was interesting to work on. I learned more about how the solar panels are placed and how to use the SAM program to help predict how much energy can be generated under certain circumstances. Though there were some struggles with gathering information and using the SAM program, I feel like I have learned quite a lot about how to use solar in projects for Design Collaborative.
Electrical Engineering Intern