BRAE 236 Drip Micro - Energy Cost New

BRAE 236 Drip Micro - Energy Cost New - Improving Energy...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Improving Energy Efficiency in in Drip Irrigation Irrigation Training and Research Center Original Material by: Dr. Charles M. Burt Modified for SCE class by: Dr. Stuart W. Styles California Polytechnic State University San Luis Obispo, California 93407 USA ITRC Cal Poly Objectives Evaluate the energy cost equation 1. 2. 3. 4. 5. Water use Distribution Uniformity Hours of operation of operation Pumping power required Energy cost ITRC Cal Poly 1 1. ET (aka (aka water use) ITRC Cal Poly Transpiration • The drier and hotter the air, the higher the transpiration rate ITRC Cal Poly 2 Wheat (non-stressed) ET ITRC Cal Poly Wheat Cumulative ET ITRC Cal Poly 3 Evaporation • Does not pass through the plant • Occurs from wet soils and/or wet plants • DOES NOT INCLUDE SPRAY LOSSES ITRC Cal Poly Evapotranspiration • Combination of E and T of and • Variations will exist between years • Published ETc values are always Published ETc values are always approximate approximate numbers ITRC Cal Poly 4 Evapotranspiration Values Evapotranspiration Rate, inches/month Decid. Month (ETp) ETr, alfalfa January February March April May June July August Sept. October November December TOTAL .88 2.41 3.75 6.19 7.98 9.03 9.32 8.44 6.03 4.55 1.92 0.71 61.2 (ETo) ETr, grass .69 1.97 3.13 5.24 6.78 7.65 7.92 7.14 5.08 3.75 1.52 0.55 51.4 Alfalfa Hay .73 1.99 3.11 5.11 6.71 7.32 7.80 6.92 5.16 3.63 1.61 .60 50.7 33.3 .48 2.06 6.68 10.03 8.76 4.47 0.77 Cotton Citrus .58 1.52 2.32 3.75 4.85 5.06 5.27 4.73 3.57 2.69 1.18 0.38 35.9 40.8 1.49 3.63 5.58 6.83 7.59 6.85 4.87 3.02 0.97 Decid. orch. w/o orch. w/ cover crop cover crop .68 1.98 3.33 5.89 8.10 9.08 9.58 8.41 5.89 3.90 1.58 0.50 58.9 28.7 .05 1.16 4.13 6.00 6.72 5.96 3.30 1.22 0.14 0.09 19.8 Grape Vines Small Grains 0.41 1.99 3.92 6.37 6.24 0.63 ITRC Cal Poly ETc Techniques (how do you get the ETc?) ITRC Cal Poly 5 First Law: There is no Magical Answer is no Magical Answer ITRC Cal Poly Crop Water Use Requires a combination of techniques combination of techniques 1. plant based measurements 2. soil moisture stress indicators 3. use published ETc values 4. measure ET measure ET - evaporation pans - computerized ETo programs and kc ITRC Cal Poly 6 Techniques for crop water use • Crop stress indicators – plant observation (color, leaf curl) – Pressure bomb – must be included with some sort of moisture deficit determination ITRC Cal Poly Techniques for crop water use • Soil moisture stress indicators – indicates when to irrigate – resistance blocks or tensiometers – Often, the absolute value of the device is not important not important ITRC Cal Poly 7 Techniques for crop water use • Published ET Values for Weekly scheduling – Caution between ETreference and ETcrop – Caution between which reference crop is used – These weekly estimates should reflect the These weekly estimates should reflect the local local weather conditions ITRC Cal Poly Techniques for crop water use • Published ET for Seasonal Estimates – cumulative ET vs. time – simple tool for scheduling certain tree simple tool for scheduling certain tree crops crops ITRC Cal Poly 8 Almonds in So. San Joaquin Valley 50 45 40 35 30 25 20 15 10 5 0 r ry M ay y ch il e Ju ly be r us t er ov em be ec em be Ap r ar br ua Ju n Ja nu Au g te m ct ob M ar r D Annual inches 16.5 52.96 42.14 58.16 40.05 25.26 42.73 53.47 27.94 44.73 38.2 50.78 25.01 40.41 33.92 27.95 19.45 26.41 35.85 17.76 21.16 27.95 40.41 38.44 25.09 40.41 40.41 30.04 41.51 20.7 0.95 1.19 0.95 0.95 0.95 1.17 0.95 0.95 0.95 1.17 0.95 0.95 0.95 0.95 1.15 0.95 0.95 0.95 1.03 0.95 0.95 1.18 1.09 0.95 0.95 0.95 1.15 0.95 Cumulative ETc Fe Se p O N ITRC Cal Poly ETc Table for Irrigation Scheduling and Design Zone 12 Monthly Evapotranspiration Drip/Micro Irrigation Typical Year IRRIGATION TRAINING AND RESEARCH CENTER, California Polytechnic State University, San Luis Obispo Table does not include adjustments for bare spots and reduced vigor 1997 (Typical Year) June July August September October November December inches inches inches inches inches inches inches 0.2 0.13 0.34 0.07 0.64 4.15 2.12 7.58 7.98 6.76 5.39 3.47 1.05 0.99 7.25 9.01 6.83 4.04 6.95 8.09 4.16 8.3 6.03 7.3 3.7 6.83 4.68 7.11 0.21 7.97 8.11 1.02 1.33 7.11 6.83 5.11 3.05 6.83 6.83 6.03 6.83 3.7 7.62 9.51 7.23 4.18 7.28 8.4 4.34 8.74 8.52 8.97 5.1 7.22 8.44 7.69 0.16 7.28 7.16 4.15 0.16 7.69 7.22 5.17 3.2 7.22 7.22 6.39 7.18 3.94 6.48 8.01 6.24 3.65 6.19 7.25 3.92 7.38 7.37 7.72 4.62 6.27 7.4 3.09 1.44 1.15 0.44 4.9 0.34 3.09 6.27 4.57 2.9 6.27 6.27 5.09 5.83 3.22 4.85 6.14 4.62 2.63 4.69 5.46 2.78 5.19 5.4 5.87 3.26 4.67 5 0.07 1.31 0.07 0.07 1.54 0.07 0.07 4.67 3.48 2.09 4.67 4.67 2.79 3.43 1.69 2.34 3.45 2.2 1.57 3.07 3.17 2.03 2.61 2.77 3.6 1.78 2.23 1.38 0.63 1.29 0.63 0.63 0.63 0.63 0.63 2.23 2.76 1.89 2.23 2.23 0.64 2.09 0.63 0.45 0.85 0.45 0.46 0.49 0.92 0.48 0.53 0.51 0.87 0.52 0.45 0.49 0.49 0.78 0.49 0.49 0.49 1.03 0.49 0.45 0.86 0.73 0.45 0.45 0.46 0.68 0.47 Precipitation Grass Reference ETo Apple, Pear, Cherry, Plum and Prune Apples, Plums, Cherries etc w/covercrop Peach, Nectarine and Apricots Immature Peaches, Nectarines, etc Almonds Almonds w/covercrop Immature Almonds Walnuts Pistachio Pistachio w/ covercrop Immature Pistachio Misc. Deciduous Cotton Misc. field crops Small Vegetables Tomatoes and Peppers Potatoes, Sugar beets, Turnip etc.. Melons, Squash, and Cucumbers Onions and Garlic Strawberries Flowers, Nursery and Christmas Tree Citrus (no ground cover) (no ground cover) Immature Citrus Avocado Misc Subtropical Grape Vines with 80% canopy Grape Vines with cover crop (80% canopy) Immature Grapes Vines with 50% canopy January inches 6.81 0.73 0.84 0.84 0.84 0.84 0.84 0.84 0.84 0.83 0.84 0.84 0.84 0.84 0.86 0.86 0.87 0.86 0.86 0.86 0.87 0.86 0.84 0.84 0.85 0.84 0.84 0.84 0.85 0.85 February inches 0.27 2.12 0.92 2.37 0.92 0.92 0.98 2.14 0.96 0.92 0.92 2.14 0.92 0.92 0.91 0.91 1.47 0.91 1.19 0.91 2.05 0.91 0.92 2.21 1.56 0.92 0.92 0.92 1.96 0.91 March inches 1.34 4.01 1.56 4.05 1.58 1.34 1.82 3.53 1.56 1.71 1.11 3.36 1.11 1.56 1.1 2.15 3.63 1.66 2.58 1.1 3.69 2.15 1.56 3.54 2.52 1.56 1.56 1.27 3.17 1.21 April inches 0.22 5.56 2.34 4.87 2.15 1.23 2.98 4.89 1.95 1.78 1.14 3.7 0.69 2.26 1 1.38 5.54 0.75 5.59 0.22 4.79 1.38 2.26 3 .9 2.23 2.26 2.26 1.14 3.11 0.82 May inches 0.21 7.32 6.53 7.87 6.04 3.45 6.48 7.62 3.96 5.8 2.65 5.26 1.54 6.23 1.71 2.62 1.62 3.69 7.78 1 5.18 2.62 6.23 4.82 2.99 6.23 6.23 3.51 5.23 2.31 www.itrc.org ITRC Cal Poly 9 Techniques for crop water use • Measuring a reference ET – Evaporation Pans • provides a reference sample • good for crops with good canopy ITRC Cal Poly ITRC Cal Poly 10 Techniques for crop water use Measuring ET • Using Computerized ET Prediction Programs – ETref or ETo – Modified Penman-Monteith equation Penman– CIMIS (california) – AGRIMET (pacific NW) ITRC Cal Poly ITRC Cal Poly 11 ITRC Cal Poly We have ETo... how do we get ETc???? • Different plants transpire water a different rates • Need the kc = Crop coefficient ITRC Cal Poly 12 Crop Water Use - ETc basic equation equation ETc = kc x Eto Or kc = ETc/ETo ITRC Cal Poly END PART 1 ITRC Cal Poly 13 2. DU (aka (aka distribution uniformity) ITRC Cal Poly “Rapid” Evaluation Characteristics 1. 2. 3. 4. 5. Reasonably accurate One day for completion day for completion GLOBAL DU – for complete field Standardized Recommendation-oriented Recommendation- ITRC Cal Poly 14 Basic Irrigation Performance Term Distribution Uniformity • Measure of how uniformly the water is distributed throughout a field • Always less than 1.00 • Always a decimal value • 0.80 is a typical DU ITRC Cal Poly DU DU POOR UNIFORMITY Depth of Water GOOD UNIFORMITY (NEVER PERFECT) Depth of Water ITRC Cal Poly 15 A “typical” drip system has flow ratio rates of… • 2 to 1 to • or worse We should do better than this ITRC Cal Poly That means you need to apply 25-80% extra water to avoid dry spots 2525-80% extra water means: • 25-80% extra pumping 25• 25-80% extra fertilizer 25• Wet spots • Workman’s comp. problems ITRC Cal Poly 16 Distribution Uniformity • Very good .95 good –With perfect timing 5% deep percolation • More typical .80 –With perfect timing 20-25% deep perfect timing 20 25% deep percolation percolation ITRC Cal Poly Microsprayer on Lemons - Yuma Mesa ID, Yuma, AZ ITRC Cal Poly 17 360 degree spray pattern near McFarland, CA ITRC Cal Poly Fan Jets on young almonds - Paramount Farming Co. Bakersfield ITRC Cal Poly 18 Pulsator on Grapes for Frost Protection, with Drip Below - Greenfield, CA - ITRC Cal Poly 3 Tapes per 80” bed - Onions - Boswell Farms 2003 Tape only inch below soil surface. ITRC Cal Poly 19 Retrieval of tape. With lettuce, there are typically 10-15 crops/tape. ITRC Cal Poly Field measurements for the drip/micro evaluation • DU measurements measurements – Pressures – Emitter flow rates – Observations • Excess pressure loss near the pump • Constraints (management and hardware) Constraints ITRC Cal Poly 20 ITRC Cal Poly Pressure gauges must be of high quality and of the proper range. We test our gauges frequently. ITRC Cal Poly Ideally, use only one gauge for all pressure measurements. Pressures are measured in the hoses, not in the PVC or manifolds. ITRC Cal Poly 21 With microspray, one must usually select 16 emitters from 2 or 3 adjacent hoses with identical pressures. ITRC Cal Poly Careful but incorrect measurement technique ITRC Cal Poly 22 Correct procedure for measuring volumes. Also – note the correct size of graduated cylinder. ITRC Cal Poly Locations of Pressure Measurements • Along hoses – Head – Middle – Downstream end • Along manifold – Hoses at entrance, middle, and d/s end at entrance middle and d/s end • Between blocks – Hoses at entrances to each manifold. ITRC Cal Poly 23 Besides measuring flows, specific observations are made. Hose ends are flushed, and emitters are cut apart. ITRC Cal Poly ITRC Using a Nylon to catch material Cal Poly 24 The contaminants are qualitatively assessed by amount and type ITRC Cal Poly Contaminated PC emitter. Often the flow rate on a PC emitter INCREASES when the disk is jammed open. ITRC Cal Poly 25 Root intrusion into row crop tape. ITRC Cal Poly ITRC Cal Poly 26 Questions are asked about chemical injection to prevent plugging. ITRC Cal Poly Observations are made regarding filtration. ITRC Cal Poly 27 Unequal Drainage At low points, emitters continue to discharge even after the system is discharge even after the system is shut off. ITRC Cal Poly Data and Results The data collection forms are standard, and the computations are automatic. ITRC Cal Poly 28 Evaluation Results from Cal Poly Student Evaluation Teams 1997-2002 Cal Poly ITRC and USBR Sacramento and San Joaquin Valleys, California 1.00 0.90 0.80 0.70 Drip Micro 0.60 DU lq Avg. DUlq values: Drip = .85 Microspray = .80 0.50 0.40 0.30 0.20 0.10 0.00 1 11 21 31 41 51 61 71 81 91 101 111 121 131 141 151 161 Field # ITRC Cal Poly Causes of non-uniformity ITRC Cal Poly Microspray and Drip Pressure Differences 44.9% Plugging, Wear, Manufacturing Variation - 51.5% Unequal Drainage - 1.1% Application Rate - 2.5% ITRC Cal Poly 29 ITRC Training • Annual evaluation classes at ITRC evaluation classes at ITRC • Designer/Manager School of Irrigation every August. ITRC Cal Poly END PART 2 ITRC Cal Poly 30 3. Hours of Operation Operation (aka (aka irrigation scheduling) scheduling) ITRC Cal Poly Basic Irrigation Performance Term Efficiency • Measure of water beneficially used in the root zone compared to the water applied • Always less than 100% • Always a percentage value • If perfect scheduling, then – Efficiency = DU * 100 ITRC Cal Poly 31 Efficiency Efficient Depth of Water Not Efficient Depth of Water ITRC Cal Poly Basic Calculations • NET = ETc • GROSS (inches) = NET/DU (if not over irrigating) • Hours = GROSS x Area / (GPM x 96.3) ITRC Cal Poly 32 END PART 3 ITRC Cal Poly 4. Pumping Power Required (aka horsepower) (aka horsepower) ITRC Cal Poly 33 Pump Fundamentals ITRC Cal Poly A quick look at just one aspect quick look at just one aspect of of pump performance in California 34 100 90 80 70 60 50 40 30 20 10 0 0 200 400 600 800 1000 1200 y = 6.7051Ln(x) + 30.209 R2 = 0.2774 ( ) 1400 1600 18 Input Kilowatts (kW) Figure C-1. Pump efficiency as a function of motor input kW for each pump tested – irrigation districts. Typical Centrifugal Pump ITRC Cal Poly 35 Typical Pump Cutaway ITRC Cal Poly Submersibles ITRC Cal Poly 36 Vertical Turbine ITRC Cal Poly Total Dynamic Head (TDH) • The total pressure which a pump imparts to the water ITRC Cal Poly 37 Total Dynamic Head Well Pump TDH of a Well Pump =Static Lift + Drawdown + Surface Discharge P + Column and Discharge Head Losses + Entrance screen loss Motor Discharge Head Discharge Pressure Ground Surface Static Lift Static Water Level Drawdown Column Pipe Pump Bowls Well Casing ITRC Cal Poly Units of Power • In pumping applications power is in units of either: – Horsepower (HP) – Kilowatts (kW) • 1 hp = 0.746 kW ITRC Cal Poly 38 Input Horsepower (IHP) • Power delivered to the pump driver (motor or engine) • IHP is the power you pay for – electricity for motors for motors – fuel for engines ITRC Cal Poly Water Horsepower (WHP) • The HP that is imparted to the water • If you do an EFFICIENCY test, you measure WHP as: WHP = TDH × GPM 3960 ITRC Cal Poly 39 Input Horsepower (IHP) • IHP is the power you pay for… • IHP = TDH × GPM 3960 3960 x e • e = pumping plant efficiency ITRC Cal Poly Pump Characteristic Curve ITRC Cal Poly 40 END PART 4 ITRC Cal Poly 5. Annual Pumping Pumping Cost (aka $$$$$$) (aka $$$$$$) ITRC Cal Poly 41 ITRC Cal Poly Summer (May-October) Energy Charge ($/kWh $0.35 $0.30 $0.25 $0.20 $0.15 $0.10 $0.05 $0.00 A G -V E -R E A G -5 E A G -4 E A G -4 F A G A G -5 F Peak 12 pm - 6 pm Partial-Peak 8:30 am - 12 pm 6 pm - 9:30 pm Off-Peak 9:30 pm - 8:30 am & & & & A G -4 B A G -4 C & A G -5 B A G -R B A G Rate Schedule ITRC Cal Poly A G -5 C -V B & 42 SCE TOU Schedules ITRC Cal Poly TOU Options • • • • Optimal: 48 hours per week Least Cost: 93 hours per week More realistic: 126 hours per week Most expensive:7-24 (168 hours) (168 ho ITRC Cal Poly 43 Annual Cost Equation = Energy Cost ($/KWH) x Horsepower (HP) x Hours of Operation x 0.746 of Operation 0.746 ITRC Cal Poly END PART 5 ITRC Cal Poly 44 Handout Annual Energy Cost Problems ITRC Cal Poly 45 ...
View Full Document

Ask a homework question - tutors are online