Dairy Milking Machine Vacuum Pump VFD Savings Calculator

1. Dairy Milking Machine Vacuum Pump VFD Savings Calculator Follow-up from the last RTF meeting with more field data Regional Technical Forum December 7, 2010

2. Overview • How the RTF calculator works • Baseline Annual Energy Consumption = 0.75 * motor nameplate hp * 0.746 * hours of operation per day * 365 • Retrofit Energy Consumption = Baseline Energy Consumption * 0.50 • Metered baseline or retrofit energy consumption data can be used to override the default calculations. • At the November 2nd, 2010 RTF meeting • The RTF voted to approve the continued use of the Dairy Vacuum Pump VFD calculator, until better data were available. • Chris Helmers offered that PacifiCorp has new data. • The group agreed that the RTF should look at PacifiCorp’s data set to ensure the calculator is providing reasonable results on the entire sample. • Since the meeting • Hours of operation and metered pre/post metered use data from an additional 82 dairies shows calculator provides reasonable, if conservative, results. • Thank you PacifiCorp and EMP2 for the data • Not all sites had both pre and post metered energy use data available • Summary of comparison of Calculated-to-Measured • Calculated baseline energy consumption usually lower than measured • Calculated retrofit energy consumption usually higher than measured • Calculated energy savings usually lower than measured • The remaining slides provide a summary of the data • Recommendation: Continue allowing use of the RTF calculator until detailed data are available from the Farm Energy Pilot Program to make improvements to the calculator (estimated late 2011).

3. Notes • Measured baseline data for WA sites probably includes other loads (whole-facility?) • Overall, calculator gives a result 16.5% lower than measured (not including WA sites).

5. Notes • Overall, calculator gives a result 23% greater than measured.

7. Notes • Overall, calculator gives a results 31% lower than measured.