Water Efficiency May 2012 : Page 32
sense the need to pump. Other utilities are embracing the demand-response method of making sure that their pumps work as effi ciently as possible, Robinson says. Under this system, utilities send e-mail messages to customers who have signed on to their demand-response programs. Customers then have a limited amount of time, usually two to 12 hours, to take a specifi c action. Th e utility might want its end users to modify the control settings on their SCADA systems to increase their water storage for a short period of time. Th is allows the utilities serving these customers to avoid using their normal high-pressure high-service pumps during a period in which to do so would consume the most energy. Th e demand-response model is growing in popularity because utilities have discovered that there are a certain number of hours each month during which their water-delivery grid faces op-erating constraints that make delivering water to their end users a more costly task. Th e goal of demand-response pro-grams is to enlist end users in the eff ort to reduce their water distribution needs during these hours. Robinson says that Honeywell is now working to equip 10 water utilities with the communications and control infrastructure to allow them to partici-pate in demand-response programs. “Th ese systems can save utilities tens of thousands of dollars a year,” says Robinson. “We have one of those photos of an oversized check being presented to a utility, and the number on that check is in the six fi gures. Th at’s a signifi cant amount of savings for a program that is relatively simple to institute.” Convincing water utilities to sign up for a demand-response program remains the real challenge, Robinson says. But the arguments in favor of such programs are becoming stronger every day, thanks largely to the nation’s weak economy. With utilities being forced to come up with more savings each year, a demand-response program—especially because it requires little new equipment and boasts a reasonable upfront pay-ment—is a fairly easy sell to city councils and boards, Robinson says. Honeywell offi cials present their end users with a clear formula showing 32 WATER EFFICIENCY WWW.WATEREFFICIENCY.NET them how much participation in the demand-response program will cost them and how much in savings it will generate each year. Th e numbers usually make the case. “As utilities are seeing reduced water usage, there is pressure on them to increase their rates. Th is is one addi-tional way of putting off rate increases as long as possible,” says Robinson. “We are seeing more participation now in these programs. Utilities are reassured when they see their peers successfully using demand-response to cut their costs. No one wants to be the fi rst adopter for technology or a new approach to doing business. Once they see it as being a successful program, once they see the magnitude of savings by their peers, they are quick to jump on the bandwagon.” SPENDING BIG FOR SAVINGS LATER Instituting programs that enlist end users aren’t the only steps that utili-ties are taking to improve their overall efficiency levels. Many are replacing antiquated water facilities, and their inefficient pumps, with new models. Th is requires a huge upfront cost. But, those municipalities that can aff ord the millions it takes to open new water treatment, and distribution plants can see big energy savings each year, thanks to the new, more effi cient pumps they’ll be employing. Just ask Emmett Autrey, director of utilities with the city of Amarillo, TX. In December, the city opened its new $18 million pump station to more effi ciently move water to its business and residential customers. Th e station has been designed to move 87 million of gallons of water a day, a signifi cant in-crease from the 73 million daily gallons of water that the station it replaced had struggled to distribute. But, while the new plant will move more water, it will actually cost the city less to do so. Th e pumps at the station are 20% more effi cient than they were at the old one, Autrey says. Th is will bring more than $220,000 a year in energy savings, he adds. Th e new plant boasts six pumps driven by 1,500-horsepower motors. It replaces a pump station that fi rst went into service about fi ve decades ago. “Th e old water plant was becoming ineffi cient,” says Autrey. “We were put-ting more and more of a hydraulic load on the pumps as the community grew. For effi ciency and capacity reasons, we went with a plan to design this new pump station.” Th e new plant relies on variable frequency drives, better known as VFDs, to run at least 50% of its pumps, Autrey says. Th is means that plant operators don’t have to turn these pumps on and off , saving wear and tear on the devices. Pumps powered by VFDs also consume less energy to operate. Th e designers of the pump station made sure, too, that the pipes and valves connected to its water pumps were de-signed to provide as little restriction as possible on the fl ow of water as it leaves the pumps. Such a seemingly small step can actually result in sizable energy sav-ings as pumps have to exert less strain to move water through a water distribution system. Th e projected effi ciency gains from the new plant’s water pumps were important. Th e predicted yearly energy savings allowed Amarillo to qualify for stimulus funds from the American Recovery and Reinvestment Act. “Being able to show that we were going to be saving about $220,000 a year made all the diff erence in the success or failure in getting that funding,” says Autrey. “Our old pumps were becom-ing very ineffi cient. Being able to boost our effi ciency by so much made a real diff erence in our eff orts to secure those stimulus funds.” Amarillo isn’t alone in seeing sizable effi ciency gains by updating aging water pumps. A large number of water dis-tricts across the country are delivering water while relying on old water pumps. As pumps age, their effi ciency levels naturally drop. New models of water pumps also tend to be more effi cient than their predecessors. At Gorman-Rupp, that certainly is the case. Redmond says that the company is constantly working on new pump designs that are more ef-fi cient than are previous generations. “Effi ciency is becoming a more important requirement on our products now,” he adds. Th e challenge remains convinc-ing water utilities to make the upfront
Publication List
Using a screen reader? Click Here