We have been changing all our lighting out to LED's to cut on energy cost's . Our plant is wanting to look at other means to save energy . We have quite a few hydraulic test stands where the operator installs the part on the stand and runs various test's at different pressure's and flow . Some times the stand run in bypass without being fully loaded . I was asked ( If a pump is running unloaded or very minimum loading , what percentage of HP is being used ) . What's the best way to answer this question ?