You may be wondering why I chose to talk about municipal water pump repairs on Intel’s Grid Insights blog. I can see people thinking, “how embarrassing, this guy didn’t even show up to the right blog.” However, I believe that globally, intelligent pump repairs represent one of the largest and simplest opportunities for energy savings available. In the future, Smart Water initiatives and Smart Grid initiatives will undoubtedly be intertwined. Consider the following:
- The EPA estimates that “3-4 percent of national electricity consumption, equivalent to approximately 56 billion kilowatt-hours (kWh), or $4 billion, is used in providing drinking water and wastewater services each year.1
- A worn pump that is operating 30 percent below peak efficiency will consume more than 50 percent more energy to deliver the same volume of water.
- American Water, a large utility that provides water and wastewater services to an estimated 15 million customers, estimates that “nearly 93 percent of [our] greenhouse gas emissions come from [our] operational electricity use, largely for pumping water”.2
- American Water should be commended for deciding to reduce its annual energy consumption by 8 percent by the end of 2016. In order to achieve this goal, American Water has made pump maintenance and upgrades a priority. 3
Pumps wear out over time, and as they wear, they become less and less efficient. At Specific Energy, we’ve tested worn pumps that are operating at over 30 percent below their peak efficiency – this is not uncommon.
How does this happen? Unfortunately, water utilities do not have the technology to assess the conditions of their pumps. Therefore, utilities typically run pumps to failure, which means that they only replace pumps once they have become so severely damaged that their pumps stop pumping. Since pumps usually take 10-15 years to finally fail, worn pumps will operate for years and years consuming 20-50 percent more energy than necessary.
At some point in the life cycle of every pump, it makes financial sense to repair the pump and have the resulting energy savings pay for the pump repair. For example, if a pump repair costs $25,000 and would realize $4,500 per year in energy savings, you can use simple present value analysis to determine the net present value of a project to repair this pump back to factory condition.
Admittedly, this is a very simple calculation. But it is the way that utilities should be thinking about their pump repairs. Any project that has a net present value of 53.5 percent should be seriously considered by any organization.
The difficult part of this calculation is determining the energy savings per year from replacing a single pump or combinations of pumps ($4,500 per year in the example above). In fact, determining the annual pump repair energy savings is an unbelievably complex task. However, Specific Energy’s software is able to accurately determine annual pump repair energy savings by using sub-second resolution operating data, accurate pump models, and advanced system models to simulate different combinations of pump repairs and the associated energy savings of each. The software’s user interface will recommend pump repairs that have the highest net present value. Monthly reports rank pump repairs by NPV to help managers and engineers intelligently plan pump repairs.
Utilities can now move from running pumps to failure to intelligently targeting pumps for repair based on actual pump station operating data, pump health data, and hard financial metrics. This is a quintessential example of how smart water can utilize big data – turning huge amounts of data into simple, actionable, and valuable metrics.
What questions do you have?
- United States Environmental Protection Agency. Water & Energy Efficiency. EPA Web Site. September 14th, 2012. Web. November 24th, 2014.
- American Water. Corporate Responsibility Report. Energy Efficiency. American Water Web Site. 2013. Web. November 24th, 2014.
- Rafter, Dan. “Water and Energy: A Crucial Conversation.” Water Efficiency. June 2013: 30-31. Print.