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"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)
There was a paper presented at the Texas A&M Pump Users Symposium a couple of years ago about using pumps in backflow as turbines to drive generators. This was explored as a possible means of providing electricity in parts of rural India. I looked briefly and didn't find the article. But you should be able to search for it.
I know that the major Australian slurry pump maunufacturer did a study to investigate the use of pumps at the end of slurry discharge lines as a source power generation.
The outcome I am not aware of.