![\"James](\"https:\/\/scadametrics.com\/blog\/wp-content\/uploads\/2025\/07\/IMG_0987-1-150x150.jpeg\")
Jim ‘Slim’ Mimlitz, SCADAmetrics<\/p><\/div>In this article, we introduce a novel method of quantifying pump station energy efficiency.<\/p>\n
For an automobile, everyone is familiar with Miles-Per-Gallon or MPG<\/strong><\/em>.\u00a0\u00a0Today, we\u00a0are going to introduce an equivalent measure of pump station efficiency that\u00a0every water utility Telemetry\/SCADA system should include: GPK<\/strong><\/em>.<\/p>\n Using the EtherMeter, a VFD (Variable Frequency Drive), and a Flow Meter to Optimize Pump Station Energy Efficiency.<\/p><\/div>\n Have you ever\u00a0calculated the average gas mileage for your automobile?\u00a0 It’s fairly simple \u2015 At\u00a0two successive\u00a0fuel tank fill-ups, check the odometer, and calculate the difference in miles: Delta-Miles<\/strong>.\u00a0 Then, after the last fill-up, note the amount of fuel added: Delta-Gallons<\/strong>.<\/p>\n Note that the above measurement provides an average<\/em> MPG achieved throughout the previous tank of fuel.<\/p>\n It is also useful to know the realtime<\/em> MPG, but this requires knowledge of the instantaneous automobile speed and the instantaneous fuel flow-rate:<\/p>\n Some late-model automobiles, assisted by an internal computer and sensors,\u00a0provide a visual display of realtime MPG on the dashboard:<\/p>\n Automobile Dashboard Display: Realtime MPG<\/p><\/div>\n Equivalently, in\u00a0a water utility, it is also possible to calculate the energy efficiency for your water pumping system:<\/p>\n Note that the above measurement provides an average<\/em> GPK achieved throughout some fixed time period.<\/p>\n As with the automobile example, it is also useful to know\u00a0the realtime<\/em> GPK, but this requires knowledge of the instantaneous Pump FlowRate (Gallons per Hour)\u00a0and instantaneous Power (KW):<\/p>\n If the pump station contains:\u00a0 (1) Flow Meter<\/a><\/strong>, (2) SCADAmetrics EtherMeter\u00ae<\/span><\/sup><\/a><\/strong>, and (3) A Full-Featured Variable Frequency Drive with Modbus<\/a><\/strong>\u00a0\u2015 then it is equipped with everything necessary to measure and trend realtime GPK:<\/p>\n Example Flow Meter: Neptune HP Turbine, 6 Inch, with E-Coder Register.<\/p><\/div>\n EtherMeter: Connects Neptune HP Turbine Meter to Station Control System via Modbus\/RTU (via RS-485 twisted pair).<\/p><\/div>\n Allen Bradley PowerFlex\u00a0VFD’s – Connected to Station Control System via Modbus\/RTU (via RS-485 twisted pair).<\/p><\/div>\n The EtherMeter provides the \u00a0GallonsPumped and FlowRate figures via Modbus:<\/p>\n A unique feature of the Allen Bradley PowerFlex\u00ae<\/span><\/sup> VFD is its ability to transmit\u00a0Kilowatt and Kilowatt-Hour figures via Modbus\/RTU:<\/p>\n Therefore, a connected PLC or SCADA system can collect these measurements \u2015 using Modbus, DF1, or EtherNet\/IP™ \u2015 to provide a running display of Pump Energy Efficiency.<\/p>\n Example Pump Station Modbus\/RTU Network.<\/p><\/div>\n Why is this measurement\u00a0important?\u00a0 Because when pump speed \u2015 and therefore flow rate \u2015\u00a0is reduced and optimized\u00a0by controlling\u00a0a VFD’s output frequency, pipeline friction losses are reduced.\u00a0 And since\u00a0friction losses are proportional to the flow-rate squared, reducing the flow-rate by even a modest factor may yield significant energy savings.\u00a0 In an extreme example, reducing flow-rate by a factor of 2 will reduce\u00a0pipeline friction losses (wasted energy) by a factor of 4.<\/p>\n In a successful real-world application, we recently observed a\u00a0Water Utility\u00a0who was able to reduce\u00a0its average pump energy consumption by a factor of 3!\u00a0 In this project, the\u00a0customer replaced soft-starters with\u00a0VFD’s and leveraged a Flow Meter\/EtherMeter combination to optimize the rate-of-flow and GPK.\u00a0 Before the introduction of the VFD’s, the pumps were\u00a0only capable of running at 100% speed\u00a0\u2015 typically pumping at a flow rate of 352.3 GPM\u00a0\u2015 with an average efficiency figure of 1328 GPK.<\/p>\n After the VFD’s were installed and optimization completed, a new average rate-of-flow was set at approximately 169.34 GPM\u00a0\u2015 yielding a new average\u00a0efficiency figure of 4033 GPK.\u00a0 At the time of this writing, the cost\u00a0per a Kilowatt-Hour is generally around $0.12, so the pump station’s energy costs were calculated to drop from\u00a0$345\/month\u00a0to $114\/month!<\/p>\n Pump \u201cGallonage\u201d (GPK) \u2013 24 Hour History Chart (above). Note that the GPK can spike up during pump ramp-up and ramp-down \u2014 This is normal.<\/p><\/div>\n Also, Rockwell Automation <\/a>offers a useful tool in the form of an\u00a0online energy savings calculator<\/a>.<\/p>\n Are you interested in learning more about how the SCADAmetrics EtherMeter can be combined with the Rockwell PowerFlex VFD within\u00a0a Modbus or DF1 or EtherNet\/IP™ network to enhance your SCADA\/Telemetry system?\u00a0 Give us a call, and we’ll be glad to help you achieve the most out of your pump energy dollar, ever in accordance with our motto:<\/p>\n “You can’t manage what you don’t measure.”<\/strong><\/em><\/p>\n In this article, we introduce a novel method of quantifying pump station energy efficiency. For an automobile, everyone is familiar with Miles-Per-Gallon or MPG.\u00a0\u00a0Today, we\u00a0are going to introduce an equivalent measure of pump station efficiency that\u00a0every water utility Telemetry\/SCADA system should include: GPK. Automobile Efficiency… Have you ever\u00a0calculated the average gas mileage for your automobile?\u00a0 …<\/span> Read More →<\/span><\/a><\/span><\/p>\n","protected":false},"author":1,"featured_media":650,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3,8,4,5],"tags":[109,13,112,111,59,110],"class_list":["post-627","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-applications","category-general","category-meteringtechnology","category-modbusprotocol","tag-energy-efficiency","tag-flow-rate","tag-gallons-per-kilowatt-hour","tag-gpk","tag-rate-of-flow","tag-vfd"],"_links":{"self":[{"href":"https:\/\/scadametrics.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/627","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/scadametrics.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/scadametrics.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/scadametrics.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/scadametrics.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=627"}],"version-history":[{"count":49,"href":"https:\/\/scadametrics.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/627\/revisions"}],"predecessor-version":[{"id":2431,"href":"https:\/\/scadametrics.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/627\/revisions\/2431"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/scadametrics.com\/blog\/index.php?rest_route=\/wp\/v2\/media\/650"}],"wp:attachment":[{"href":"https:\/\/scadametrics.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=627"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/scadametrics.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=627"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/scadametrics.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=627"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"EtherMeter,](\"https:\/\/scadametrics.com\/blog\/wp-content\/uploads\/2015\/02\/VFD_EtherMeter_FlowMeter_001s.jpg\")
<\/a>Automobile Efficiency…<\/strong><\/h3>\n
<\/a><\/p>\nMPG (Miles per Gallon) = Delta-Miles \/ Delta-Gallons<\/strong><\/em><\/pre>\n
MPG (realtime) = Speed (MPH) \/ FuelRate (Gallons\/Hour)<\/strong><\/em><\/pre>\n
<\/a>Pump Station Efficiency…<\/strong><\/h3>\n
<\/a><\/p>\nGPK (Gallons per KilowattHour) = GallonsPumped \/ KilowattHours<\/strong><\/em><\/pre>\n
GPK (realtime) = 60 x FlowRate(GPM) \/ Kilowatts<\/strong><\/em><\/pre>\n
<\/a><\/a><\/a>40001-40002: Totalization (Gallons)\n40005-40006: Rate-of-Flow (GPM)<\/strong><\/pre>\n
40011: Output Power (KW)\n40012: Elapsed Energy (MWH)\n40016: Elapsed Energy (KWH)<\/strong><\/pre>\n
<\/a><\/a>\u2015\u00a0Fred Smith, Founder Federal Express<\/strong><\/h6>\n","protected":false},"excerpt":{"rendered":"