The first step in creating the two new energy systems for Tyson was to simulate each system to demonstrate the viability and financial benefits of each system. As a part of this analysis, the details of each system’s physical implementation needed to be specified in order to gain insight into the exact cost and limitations of each system. These design objectives were achieved using the following methods:

  1. System energy modeling using the System Advisor Model (SAM)
  2. Electrical distribution design using single-line diagrams


Before the new systems could be physically built, our team completed an in-depth analysis of each system in the design. 

The National Renewable Energy Laboratory (NREL) developed a free software called System Advisory Model (SAM). SAM takes all of the system inputs such as equipment model number, local insolation, and financial parameters. Given this information, SAM simulates how the system would run. Outputs include total annual energy produced, levelized cost of energy, and performance over the equipment’s lifetime.

HQ Solar Array


  • Local solar insolation data
  • SunPower panel nameplate data
  • SolarEdge inverter nameplate data
  • Energy demand in HQ
  • Estimated costs of labor and additional materials

Key Outputs

  • Annual energy production
  • Levelized cost of energy
  • Simple payback period
  • Progress to net-zero

LLC Battery Backup


  • Local solar insolation data
  • Nameplate data for existing solar array
  • Other existing equipment data and design parameters

Key Outputs

  • Powerwall longevity during an outage under different weather conditions
  • Weather probabilities in a given month
  • Progress to net-zero

The SAM analysis provides detailed system information that gives the user a good idea of how a new system will perform and if it is a cost-effective project.

The SAM results can be found here

Single-Line Design Process

Our team employed an iterative design process using single-line diagrams to detail the physical implementation of the new solar array and battery backup systems.

Single-line diagrams (or one-line diagrams) are a simplified way of displaying a complex electrical distribution system, using single lines to represent conductors and basic graphical symbols to represent panel boards, switches, and other electrical equipment. These diagrams contain a variety of information ranging from the number of panels connected to an inverter to the size of conduit and conductor runs between devices. 

The iterative design process consisted of the following three steps

1. Data Collection

Data is collected about existing electrical infrastructure, and expectations of the new system are discussed with the Tyson Facilities management. This information provides a framework to guide the single-line design. More information about our data collection methods are discussed here. 

2. Single-Line Design

A single-line diagram is created to detail the location of electrical devices and the distribution networks that connect them. The layout specifies how devices such as solar inverters and electrical disconnects need to be wired together in order to achieve the system goals set for the system in step 1, while maintaining an operationally safe and physically viable design. More information about the single lines created during this step can be found here.

3. Design Verification

Review the single-line diagrams with Tyson and EFS Energy to ensure that the design follows safety codes and meets the desired system requirements. Acquire more system information and mistake corrections to include in the next iteration.

This process continues until our team, Tyson, and EFS believe the diagrams accurately represent the system to be installed.

The final step will be to present the single-line diagrams for bid to electrical contractors recommended by the Washington University Facilities Department. Once the bids are assessed and a contractor is chosen to carry-out the necessary electrical work, the physical construction of the system can begin.