This page explains the calculation methodology for lifetime energy savings in BOS and explains the steps to setup energy savings for a site.
Calculation Methodology
- Turntide power usage (Green line) is measured by TT motor controllers from current, voltage and rpm data points. This results in Turntide Electrical Power.
- The measured Turntide electrical power is converted into the mechanical motor load utilizing the Turntide motor system efficiency. The system efficiency is known from Turntide lab tests for a given rpm and torque operating combination. This step is done for the largest 2,000 data points immediately after installation measured by Turntide Motor Controllers.
- TT_motor_load = TT_electrical_power * TT_efficiency
- The baseline motor load is calculated with affinity laws assuming that baseline motors ran at 100% speed rpms
- Baseline_motor_load = (TT_motor_load )* ((INDUCTION_MAX_RPM / TT_RPM)^3)
- The baseline motor power (Red Line) is calculated from the baseline motor load and nameplate efficiency information
- Baseline_electrical_power = Baseline_motor_load / baseline_efficiency
- The compressor penalty (Blue Line) is calculated based on nameplate RTU tonnage and added to the Turntide power draw during times when RTU is in a cooling stage.
- The difference between Baseline Power (Red Line) and TT Power with compressor penalty (Blue Line) is used to calculate the Lifetime kWh Savings, assuming that baseline and Turntide run-hours are the same.
- Utility Savings are calculated using the user-specified utility rate and demand rate.
- CO2 Emissions Reduction (metric tons) is calculated utilizing CO₂e grid intensity user input.
Setting up Lifetime Savings
- Enable Energy Savings under Site Settings for a given site in an organization. This can only be done by organization admins. Please contact your organizational admin for help with this step.
- After Energy Savings is enabled for a site, a new Energy Savings tab will appear on the site page.
- Click the Site Setup section to enter the utility rate, demand rate and CO2e grid intensity for a given site.
- Click the Motor Setup popup to populate the baseline motor nameplate and RTU nameplate information. This can be done for as few as 1 motor or all motors at the site.
- After Motor Setup is Saved, it will take 5-10mins to update the analytics chart with the baseline and Turntide power data and ~30-60min for the 4 savings metric tiles to populate. The actual length of processing time is dependent on the data history for each motor. After the motors are setup the savings metrics will be automatically every hour.
- After the savings are setup, if any of the Motor Setup inputs are changed, the baseline power, Turntide power and savings calculations are reset and recalculated from the installation date.
- Once the calculations are processed, each motor's savings metrics can be reviewed via the dropdown selector.