1. Pumping Plant Conversions- Energy and Air Implications for Improving Pumping Plants Dennis K. Carman, P.E. National Water Management Center Newport, Rhode Island April 20-21, 2005

2. Today’s Objective Identify primary reasons to make pumping plant conversions and how to evaluate –Focus on energy uses How to evaluate How to determine cost How to compare systems –Discuss Air Quality Implications Present a potential approach for expanding into an evaluation process

3. Pumping Plants Primary uses –Pumping water (irrigation) –Manure Transfer For today’s efforts we will focus only on the irrigation activities

4. Why would a farmer consider a pumping plant conversion? Energy savings –Energy costs are increasing –Pumping water is a major energy user on some farms Air quality improvements –Farmer view –In or out of a non-attainment area? –EQIP or state cost share incentive available –Earn a CSP enhancement payment

5. Pumping Plants and Energy What makes a difference? The power unit –Internal combustion engine an inefficient engine wastes fuel –get a tune-up –Electricity less likely for improvement The pump –A primary potential for improvement –Pump selection needs to match the conditions The pumping depth –What is the lift? –Greater the depth (lift) the more energy required The application method and amount pumped –Application method influences the pumping discharge pressure –Application method could influence the amount pumped –Amount pumped influences the total energy costs

6. Causes for excessive fuel use include: 1) Poor pump selection Pumps are designed for a particular discharge, head and speed. Operation outside of those parameters result in increased energy usePumps are designed for a particular discharge, head and speed. Operation outside of those parameters result in increased energy use 2) Pumps out of adjustment or worn-out pumps Pumps need adjustment from time to time to compensate for wearPumps need adjustment from time to time to compensate for wear 3) Improperly sized engines or motors Power plants must be matched to the pump for efficient operationsPower plants must be matched to the pump for efficient operations 4) Engines in need of maintenance and/or repair For internal combustion engines a tune up can be criticalFor internal combustion engines a tune up can be critical 5) Improperly matched gear heads Gear head pump drives must fit the load and speed requirements of the pump and engineGear head pump drives must fit the load and speed requirements of the pump and engine Performance evaluations indicate, on average, irrigation pumping plants in Kansas use about 40 percent more fuel than necessary.

7. How do we evaluate pumping plants? Perform a pumping plant performance evaluation –The most accurate –Relatively time consuming –Farmers reluctant to spend money to find out if something is wrong Irrigation pumping energy audit –Compare energy costs (bills) to an established standard –Use the results of this evaluation to determine if changes are necessary Cost verses benefits –Less costly, less time consuming, less accurate

8. What is needed for the irrigation pumping energy audit? 1) Acres Irrigated 2) Discharge rate 3) Total dynamic head 4) Total application depth 5) Total fuel bill 6) Fuel price per unit

9. Definitions Total dynamic head (TDH) –Estimated by adding the total pumping lift and pressure at the pump. Example: 150 feet of lift plus 45 PSI. 45 PSI = 45x2.31 or 104 feet of head. TDH = 150 feet + 104 feet = 254 feet TDH Water horsepower –A measure of the power input to the water and can be determined from total dynamic head and flow rate Water horsepower-hour –A measure of the water horsepower work or energy input for 1 hour Nebraska Pumping Plant Performance Criteria (NPC) –Criteria developed in the early 1960’s and recognized throughout the United States as the standard for comparison. BTU –A measure of energy. British Thermal Unit. Energy sources have different energy content. This unit allows us to compare energy sources, energy costs, and energy options.

10. Step 1 Determine the Water Horsepower Water horsepower (WHP) is the amount of work done on the water –WHP = TDH x GPM ÷ 3960 GPM = discharge rate in gallons per minute –Example: 600 GPM TDH = total dynamic head (in feet) –Example: 150 feet lift + 104 feet pump pressure = 254 feet TDH WHP = 254 x 600 ÷ 3960 = 38.5

11. Step 2 Calculate hours of pumping –HR = D x acres ÷ (GPM ÷ 450) HR = Hours of pumping D = Depth of applied irrigation water (inches) Acres = Acres irrigated GPM = discharge rate in gallons per minute 450 = a constant for conversion (1 acre-inch/hour = 450 gallons/minute) –Example: for 1 inch of application and 100 acres HR = 1 inch x 100 acres x (600 GPM ÷ 450) = 133.3

12. Step 3 Estimate Hourly NPC fuel use –FU = WHP ÷ NPC FU = Hourly fuel use using the Nebraska criteria WHP = Water horsepower from step 1 NPC = Nebraska Performance Criteria Energy Source WHP-HRS per Unit of Fuel Diesel 12.5 per gallon Propane 6.89 per gallon Natural Gas (925 BTU/cf) 61.7 per MCF Electricity 0.885 per KWH (kilowatt-hour) For our example: WHP = 38.5 from step 1 FU = 38.5 ÷ (12.5) or (6.89) or (61.7) or (0.885)

13. Step 4 Estimate Seasonal NPC fuel cost –SFC = FU x HR x Cost SFC = Seasonal fuel cost if the pump was operating at NPC standard HR = Hours of operation from Step 2 Cost = $ per fuel unit Continuing with our example and selecting diesel as our energy source –SFC = (38.5 ÷ 12.5) x 133.3 x $2.00 per gallon diesel = $821.00 to pump 1 inch of water for the 100 acres

14. Step 5 Determine excess fuel cost –EFC = AFC – SFC –EFC = Excess Fuel Cost in dollars –AFC = Actual Fuel Cost in Dollars –SFC = Estimated Seasonal Fuel Cost using NPC in dollars –Continuing with our example: Let’s assume we pumped 10 inches of water during the year Our fuel cost should have been about $8200 for the year If we were significantly more than this value we should consider a more extensive evaluation

15. How do I compare energy sources? Electricity1.0143.0133.071.128 Natural Gas (925 BTU/cf) 69.721.9254.948.98 Diesel14.120.2030.18711.81 Propane7.790.1120.1030.5511 Cost equivalent Fuel Multiplier table Example: Focusing on column 2 from the table above A value of 1 is listed for electricity A value of 14.12 is listed for Diesel This means a gallon of Diesel will produce 14.12 times as many water horsepower-hour outputs per gallon as 1kWh of electricity

16. Which source is best? It depends on a lot of considerations with energy cost being one Let’s continue with our example of 100 acres applying 10 inches of water Continuing with our example and selecting diesel as our energy source SFC = (38.5 ÷ 12.5) x 133.3 x $2.00 per gallon diesel = $8210 to pump 10 inches of water for the 100 acres Equivalent energy sources would be: Electricity: $2.00 x.071 = $0.14 per kWh Propane: $2.00 x 0.551 = $1.10 per gallon Natural Gas: $2.00 x 4.94 = $9.88 per mcf PA natural gas $11.53 per thousand NJ propane $0.985 per gallon MD electricity $0.10 per kWh

17. Further evaluations An economic assessment can be made to determine the probability for payback Perform a pumping plant performance evaluation –Determine the most logical problem and recommended fixes

18. What are the Air Quality Implications? How can we improve air quality? –Electric motors Use less energy (pump less water or reduce head) –Fix or replace pumps –Select irrigation systems with lower operating pressures –Alternative source of water at less depth (surface water) –Reduce amount of water used by improving efficiencies –Internal Combustion Engines Fix pumps Engine tune-ups

19. How do we evaluate this? Electric Motors Electric motors can be evaluated by using the previous energy audit process Specific attention paid to factors influencing –Lift (reduced lift, less energy) –Operating pressure (lower pressure, less energy) –Depth of water applied (improved efficiencies result in less water applied) In any situation, the pump and motor need to be selected for the conditions

20. How do we evaluate this? Internal Combustion Engines California evaluation example - Diesel –Considerations Existing engine size Hours of operation Model year of the engine NOx emissions reduction (tons/year) Attainment status (geographic zone)

22. See Pump Emissions Calculations Sheet

24. Future Development Work is being done on the energy front for CSP –Energy audits –Self Assessment –On-line process Air Quality –Technology is moving forward –New emphasis

25. The U.S. Department of Agriculture prohibits discrimination in its programs on the basis of race, color, national origin, sex, religion, age, disability, political beliefs and marital or family status.