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Andrew J. Staples

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Golf course energy usePart 2: Pump stationsPump stations and water use can be managed to decreaseenergy costs on goif courses.

Editor's note: This article is the second in a three-part series about energy use on golf courses. The series is based on a

utility-funded energy efficiency outreach program to 320 golf courses in Southern California conducted from 2006 to 2008.

The program was trie first energy outreach program of its kind and completely free to the customer, it identified areas Of

energy savings opportunity, focusing attention on irrigation and water management as welt as lighting and golf car charg-

ing. The program provided the customer with a cost-benefit analysis for potential work performed. Samples indicated a

potential of 30% energy savings for participating courses.

Quick fact No. 1: Experts suggest that pump-ing systems account (or 20% of the world's energydemands (3).

Quick fact NO. 2: A golf irrigation pump sta-tion can account for up to 50% of a gait coursefacility's energy use (information from the GolfResource Group energy program in SouthernCalifornia).

Quick fact NO. 3: If applied improperly, a variable

speed drive can make a pump station less energy-efficient than a typical hxcd-specd station (1).

Our outreach program has found that mostsuperintendents control the single piece of equip-ment thai consumes the most energy on the gollcourse, the pump station. (For example, a typi-cal four-pump system, where each pump has 75horsepower, draws approximately 225 kilowatts,whereas a typical clubhouse building normallydraws less than 100 kilowatts.) The pump station

Tlie pump station for the Chiricahua Course, The Desert Mountain Club, Scottsdale, Ariz. Photos by Jim Key, CGCS

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I EnergyD Maintenance and repair

D Loss of productionCH Purchase and installation

D Operational• Decontamination and removal

Figure 1. The percentage allotted to eacli cost for a typical pump over its lifetime. Although exactvalues may differ, ttiese percentages are consistent with those published by leading manufacturersand end-users, as well as industry associations and government agencies worldwide.

Overall pumping plant efficiency ranges

Motor HP

3-5

7-10

1b 3u

40-60

75 -up

Low %

41 .9 or less

44. 9 or less

47.9 or less

52.9 or less

55.9 cr less

Fair%42-49.Q

45-52.6

48-55.9

53-59.9

56-62.9

Good % Excellent %50-54.9 55 or above

53-57.9 58 w absve

56-60.9 61 a above

60-64.9 65 or above

63-68.9 69 or above

Nate; The above values were developed by the Center for Irrigation Technology (CIT).

Table 1. Overall pumping plant efficiency ranges. Brand-new pimps should fall in the excellentrange.

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is also the mam component responsible tor mak-ing sure the course is watered every night, ensur-ing optimal playing conditions for the payingcustomers. Despite its fundamental importanceto the success of the golf course, the pump sta-tion is often underappreciated and even ignored,with maintenance postponed until it is no longerfunc [ion ing.

What is the true cost of efficientpumping?

Experts suggest that rhe initial cost of a pump is12% of its cost over its 20-year lifetime (2) (Figure)), Therefore, if a pump is purchased for $35.000,the total cost over the life of the pump is $292,000.This means $175,200 will be spent on energy andmaintenance over the life of one pump. Most golfcourse pump stations consist of more than onepump, ranging from as few as two or three to 10 ormore. Doesn't it make sense to ensure these pumpsare operated at optimal efficiency?

Often a golf course pump station is describedby using the total gallons per minute at a speci-fied amount of pressure. For example, a stationis designed to pump 2,500 gallons /mi nine at 115pounds/square inch. However, to accurately assessa pump station's efficiency, its operating pumpingplant efficiency (or OPE), which measures howefficiently a motor powers a pump to deliver waterto the system, must be calculated. To make thiscalculation, the amount of power correspond ing tothe rate of flow and total heads (pump lift and dis-charge pressure) needs to be measured (Table 1).

Rarely is the pump station described in termsof efficiency, most likely because the pump sta-tion's efficiency is rarely known. However, becausea pump station wears down slowly over time,reducing output, a station may be producing 10%to 20% less than it should because of pump inef-ficiency. As energy costs continue to rise, knowinga pump's operating pumping plant efficiency willbecome increasingly important.

What is the true cost of inefficientpumping?

In rhe example above, a golf course pays$35,000 for a single pump and spends $175,200on energy and maintenance over the life span ofa pump. Therefore, for eight pumps, the coursewould spend $1,401,600 on energy and mainte-nance over the pumps' life span. If each pump isoperating at 90% efficiency, an extra $140,160will be spent over the life of the pumps, whichtranslates to an extra $7,003 per year. In addi-tion, there will be 10% more wear on the motor,bearing, s h a f t and impeller of each pump, and, intheory, the pumps will be replaced 10% sooner.

How to save energy and moneyA golf course should focus on improvements

that have the greatest in i t ia l impact and the quick-est payback for the investment made. Pump sta-tions consume more energy than any other equip-ment on a golf course because of the size of the

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To achieve maximum energyefficiency, golf courses should

always call in a professionalto program a new pump or a

new pumping station to fit theirrigation schedule.

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pump motors and the energy required to powerthe pumps. Because billing is based on rhe totalload on the power system, a pump station will costmore to operate as more horsepower is used (andtherefore, more kilowatts are drawn).

Based on results from our energy program inSouthern California, the easiest available savingswith the shortest financial paybacks come fromthree areas.• Installing energy-efficient hardware: a variable

frequency drive; a 15- to 40-horsepower jockeypump controlled by a variable frequency drive;and National Electrical Manufacturers Asso-ciation (NEMA) Premium efficiency-ratedmotors

• Operating the pumping system to ensure thepump runs it its best efficiency point (BEP)for as long as feasible, maximizing the amountof flow to the amount of demand from thesprinkler heads

• Watering less; therefore, pumping less

Installing energy-efficient hardwareVariable frequency drives

When applied properly, a variable frequencydrive is perhaps the single largest energy-savingmeasure available to golf course pump stations.The drives give pumps the ability to "soft start,"which allows the motor to slowly ramp up to fullspeed. Variable frequency drives increase the abil-ity to control flow relative to the amount of energyused by fixed-speed pumps. The soft start can alsoreduce the amount of wear and tear on the irriga-

tion system by reducing water hammer and pro-longing the life of the pipes. Because golf coursewatering demands vary throughout the year, avariable frequency drive on a pump is a necessitywhen it comes to managing energy use. Evidencegathered by the Golf Resource Group over thecourse of the outreach program suggests a singlewell pump can also benefit from the addition ofa variable frequency drive. Because flows fromgroundwater vary throughout the year, a variablefrequency drive can adjust to account for thesevariances, cutting the cost of pumping dtamad-cally.

The incteasing popularity of the variable fte-qucncy drive has brought with it a number of mis-applications that actually increase energy costs (1).For example, if a pumping station operates only atmaximum flow rare for a short period of time orat low flow rates for an extended period of time,the pumps will be running inefficiently and ofitheir BEP on the pump curve, causing an increasein energy costs. Investigation into these misap-plications by a pumping expert is recommended.These problems can arise when new pumps or anew pumping station are installed without beingprofessionally programmed to fit the irrigationschedule.

jockey pump controlled by a variable frequency driveThe outreach program in Southern Califor-

nia discovered that golf courses have moved awayfrom smaller-sized jockey pumps (pumps in the15- to 25-horsepowet tange designed to handle

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Typical pump life cycle costs

400 800

Capacity (U.S. gallons/minute)

1200

Figure 2. The pump curve shows trie effect of increasing or decreasing pressure on pump production. Ttiebowl power is the power input required to generate a given flow or pressure. Bowl efficiency is the ratio ofhydraulic power output from the bowl lo the power input to the bowl. The Best Efficiency Point (BEP) is Ltiepoint of the highest bowl efficiency. The operating point should be as close to the Best Efficiency Point aspossible. NPSHr is new positive tiead suction, which is the pressure required on the intake side of the pumpto ensure proper operation. Graph courtesy of Rain Bird

Premium efficiency motor savings

Standard Annual kWh Premiumuj,or efficiency 2000 hours Efficiency

AnnualkWh 2000

HoursEnergy EnergySavings Sayings

HP

25

50

100

150

motor operation

90 31,000

91,2 61,357

92.7 120,679

93.1 180,331

Motor

93.9

94.8

95.4

9b8

Operation

29,800

59,044

117,271

175,136

kWh/Vear

1.280

2,313

3,408

5,195

S/Year

$143

$25-1

$375

$ 5 / 1

'Cost per kilowatt hour = $0.11.

Table 2, Premium efficiency-rated motors pay for themselves within a short period of time.

small watering demands) to larger pumps run ona variable frequency drive. The thinking behindthis change is that smaller-sized pumps would nolonger be necessary because the variable frequencydrive on a larger pump would take care of bothlower and higher pumping and energy demands.

This solution is not energy efficient becausethe larger pump operates at low flow rates forextended periods of time for smaller applicationssuch as hand-watering or running a few sprinklerheads. Because the flow tares are not ar maximumcapacity, the pump is not operarmg at its BEPon the pump curve, causing an inefficient use ofenergy (Figure 2),

To determine whet her energy is being used effi-ciently, measure kilowatt hours against the overallamount of water being pumped (usually measuredin acre-leet). The lowest amount ol kilowatt hoursused per acre-foot of water pumped will be mea-sured when a pump is operating at the highestpoint on the pump curve. When flow rates are lowfor long periods of time, it takes more kilowatthours to pump the same amount of water, and thevariable frequency drive causes the pump to runinefficiently. If this happens continually, the inef-ficiencies become greater over time and increaseenergy costs even more.

In areas like Southern California, golf coursescan use a smaller jockey pump for hand-wateringand syringing at peak rate times and lock outlarger pumps from being used to eliminate thehigher charges incurred by the larger pumps. Theextra cost of a jockey pump with a variable fre-quency drive will increase the init ial upfront costsof a new pump station. However, for the 15 to 20energy assessments in our program where a jockeywas an option, it was estimated that these cosrswould often be tecovered in less than five years,

Premium efficiency-rated motorsUpgrading to National Electrical Manufactur-

ers Association's (NEMA) Premium efficiency-rated pump motors is probably the easiest shovel-ready project any golf course can undertake. Theinvestment is straightforward: install electricmotors having the highest electrical energy effi-ciency commensurate with your needs. (Makesure the motors are actually NEMA-rated Pre-mium efficiency motors because classificationscan be misleading.) Premium efficiency motorscan pay for themselves within a few years andsometimes in as little as a few months (Table 2).These motors will continue to save in energy costswell beyond their purchase cost. Understandingttue operating costs and not just initial investmentcosts should be the motivating factor when mak-

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ing energy-efficient upgrades.

Efficient pumping system operationManaging pump performance is critical to

realizing maximum energy savings. One of theeasiest ways to use energy efficiently is to maxi-mize the output of the pump station to match theexact output of each pump. In other words, if a75-horsepower pump's maximum output is 750gallons/minute, then the irrigation program forthat pump should be designed for 750 gallons/minute. It is surprising how often rhis simple con-cept has been overlooked. Each pump used dur-ing each irrigation program should be designedto reach maximum flow or the pump will nor.optimize its energy use. Since this is not alwaysfeasible, rhe idea is to design the irrigation pro-gram to push each pump to the maximum capac-ity as much as possible. For pumps with a variablefrequency drive, maximizing the output of eachpump minimizes the potential of running thepumps at low flow rates for extended periods oftime and optimizes the energy needed to pumpwater.

Operating individual pumps is only part ofthe equation. Making sure all rhe pumps on thesystem are working m sequence with each othermaximizes the hill potential for saving energy. Forexample, ar the Chiricahua course at The DesertMountain Club (see the sidebar), maximizingthe time each pump was opetated while balanc-ing the total output to the system saved the coursethousands of dollars. Some pumps were takenoffline during certain times during the year, andthe course used a lowet gal Ion-per-minute output.In addition, because some well pumps were onthe same meter as the pump stacion, rhe use ofthese wells was shifted to different times of theday. The local urility company charged addirionalfees for increased amounts of demand on rhe sys-tem, making it more cost-effective to use rhe wellpumps when rhe golf course was not irrigating.This meant the irrigation lakes were filled a l itt lelater in the day or earlier in the evening before theirrigation cycle began.

Accurate and up-to-date irrigation systemprogramming together with proper hydraulics iscritical for optimizing energy use. In particular,the flow and pressure output of the pump sta-tion must match the size of the mainl ine pipingsystem. Experts .suggest a majority of pumpingsystems on golf courses are designed incorrectlyfor the irrigation system they operate. Either thepump flow or pressure is too high or the mainlines ate too small. All these factors should be con-sidered when programming an existing irrigation

Cost savings: A case study

In some instances, it may be advantageous for a course to reduce the overall kilowatt demand onthe system by taking pumps offline and lengthening the watering window cycle to yield additionalsavings. In 2006, energy costs on the Chiricahua Golf Course at The Desert Mountain Club, Scotts-daie, Ariz., had risen 40% from 2004, an increase of $110,000.

Existing conditions-> 2.225 total horsepower or 1,659 total kilowatts of demand-> three transfer pump stations-> six 200-horsepower pumps, three 250 -horsepower pumps-> one goll course pump station-> seven 75-horsepower pumps, two boosters

Solution-> Instituted a kilowatt demand management plan for how and when the goll course pumped

its water-> Reduced the kilowatt demand by taking some pumps completely offline during periods of

the year•* Programmed system to stage pumping, minimizing multiple pumps being run at the same time-> Increased the length of the golf course watering window (Figure 3)

Run cycle* — winter monthsOption 1 —4,000 gallons/minute -A.5 hoursOption 2 — 3,000 gallons/minute - 5 hoursOption 3 — 1,800 gallons/minute - 6.5 hoursRun cycle* — summer monthsOption 1 — 4,000 gallons/minute - 7 hoursOption 2 — 3,000 gallons/minute - 8 hoursOption 3 — 1 ,BOO gallons/minute -10.5 hours

'Mote: to obtain maximum energy efficiency, each run cycle should be based on Itie maximum flowof each pump. Reducing hie gallon/minute output without adding or subtracting horsepower willresult in an inefficient use of energy,

ResultA reduction of the cost of energy by 27% (billing rales Increased 20% during the same period).

Figure 3. Left, How the station at Desert Mountain operated when the program was designed to pump themaximum amount of water over the shortest period of time (4,010 gpm). Right, Total output of the stationwas reduced (2,260 gpm) to reduce the total number of horsepower used to pump water. As a result,the water window was spread out (while pumping the same number of gallons), reducing overall kilowattdemand on the system over this period of time and reducing kilowatt demand charges from the utility.

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To save energy costs, theirrigation lakes were filledlater in the clay or earlierin the evening before the

irrigation cycle began.

IThe research says

-> A pump station is fundamen-tal to the success of the golf course,and it consumes more energy thanany other piece of equipment at thefacility.

-> To save energy and boostpump efficiency, install variable fre-quency drives on pumps, use a jockeypump for small watering jobs and usePremium efficiency-rated motors.

-> To increase pumping effi-ciency, design the irrigation programto match the maximum output of eachpump.

-> Water less to reduce theamount of energy used; alter the lay-out or design of the course to reducefeatures that require a lot of water.

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system or upgrading and replacing a pump station,Every golf course should, whenever feasible, hirea qualified irrigation design consultant to assist inthe final selection of pumping systems and ovetallirrigation system programming.

One of the biggest misconceptions found in theoutreach program in Southern California is that anew pump station is automatically more efficientthan the oldet existing pump station. The outreachprogram found that proper pump and irrigationsystem programming is essential to efficient pump-ing. In almost every case, the old pump station wasreplaced with a more efficient and therefore larger-capacity system, but few, if any, modi fie at ions weremade to the outflow pipe delivery system. The addi-rional output eoupled with the lack of programmingcaused the system to run less efficiently than it couldhave. As a result, the new system used the same or,in some cases, more energy than the old one.

Watering lessA golf course has another option to reduce

energy use — water less, Water use ha.s been andwill continue to be one of the major environmentalconcerns of golf courses. Factors such as location,design, layout and soil type all affect how muchwatet a golf course requires, and the amount ofwatet varies greatly from one course to another,even within the same region. Watering less reducesdependency on the maximum output of a pumpstation and places less priority on making sure acourse is watered in the least amount of time pos-sible. Reducing a pump's total output means thatless energy is needed to apply the water to the golfcourse. Therefore, less watering equals less energyconsumed.

Although watering less can be accomplishedwith little to no adjustment to the golf coursedesign and layout, making adjustments to thecourse wil l have the gteatest impact because turfacreage, bunker style, si/e and scale ot mounding,etc., are directly related to the resources requiredto maintain the course to the standards necessaryto attract and keep golfers. A course with severeslopes, large bunkers and greens or vast out-of-playirrigated areas increases maintenance costs. There-fore, adjusting the design of these features (with-out changing the way a course plays) ean make atremendous difference in all costs related to long-term management, including energy use.

ConclusionsUnderstanding how a golf course uses energy

can enable superintendents to use energy moreefficiently and reduce overall kilowatt demand.Demand savings can be found in areas such as irri-gation ptogtammmg, pumping system hydraulicsand staging of sprinklers as well as overall watermanagement. Investigating these a teas may increaseupfront costs, but could also identify latge savingsopportunities. As resources become more scarceor more expensive or both, adjustments in overallmanagement will become increasingly important.

Literature cited1. Hovstadius, G. 2006. Understanding the economics of vari-

able speed pumping. ITT Flygt Corp. and PlantServices.com.www.plantservices.com/articles/2006/0i7.htmi (verifiedJune 2, 2009],

2. U.S. Department of Energy. 2001. A guide to LCC analysisfor pumping systems. Pump life cycle costs: executive sum-mary. Office of Industrial Technologies Energy Efficiency andRenewable Energy, www! .eere.energy.gov/industry/best-practices/pdfs/pumplcc_1001,pdf (verified June 2,2009).

3. U.S. Department of Energy. 2005. Energy Efficiency andRenewable Energy Industrial Technologies Program — BestPractices, www1.eere.energy.gov/industry/bestpraclices/printable_versians/news_detail.asp?news_id=9035 (veri-fied June 2, 2009),

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Andrew J. Slaples (astaples@gollresourcegroup.net) is thepresident of Golf Resource Group Inc. in Phoenix. Staples andAndy Slack will be co-teaching a new seminar titled "Waterconservation and energy efficiency management for golfirrigation systems" for the 201OGCSAA Education Conferenceat the Golf Industry Show in San Diego.

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