Energy Conservation on Dairy Farms

Ted Probert

Regional Dairy Specialist

Energy Conservation – Win/Wingy /

• What is needed to conserve energy?gy

– Adapt new technology• Variable speed vacuum pumps

– Upgrade older less efficient equipment• Reciprocating compressors to Scroll types

– Change management practices– Change management practices• Scheduled maintenance program• Contracting schedule maintenance

Energy Conservation ≠ Sacrifice

Making educated choices may benefityou in more ways than one.

Dairy Farm Energy UsageMichigan 2010

Dairy Farm Energy Usage

•Milk cooling 20 %•Water heating & waterers 18%g•Lighting 16%•Manure handling 14%•Milking 12%•Milking 12%•Ventilation 8%•Space Heating 4%

d•Feeding 2%•Miscellaneous 6%

Milk Cooling

100oF 40oF

Milk Cooling

100oF 40oF

Milk

Btu =heat required to changetemperature of 1 # of water 1oF.

Cow gives 35# ofgmilk /milking in 5 minutes

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Milkfrom

Milkfrom

Milkfrom

Milkfrom from

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70lbday × 60Btu/lb = 4,200 Btu/day

D i F E UDairy Farm Energy Usage

•200 milking cow herd

•70#/day per milking cow•70#/day per milking cow

•840,000 Btu/day• >300 MMBtu/yr

•>10 Homes Energy Usage/yr>10 Homes Energy Usage/yr 

Plate Cooler – Pre‐cooler

• One of the best energy investments

l l• In‐line pre‐cooler

• Prior to bulk storage tank

Plate CoolersPlate Coolers

• Wall‐mounted• Floor‐mounted• Various Sizes – flow based

Pl t C lPlate Cooler

•Cools milk 20°F to 40°F•Depends on Flow Rate and Number of Plates

•Water runs adjacent to milk

•50°F well water temperature

•Reduces condensing unit run time

100oF 40oF100 F 40 F

Milk

ΔT = 60oF

1 Btu / # of milk cooled 1oF

60 Btu / # of milk cooled

Milk must be cooled to 40oF in 2 hours

Ground water isat about 50oF

Cooling capacity of well wateris about 440 Btu/gal

8 lb/gal × 55 Btu

Milk Cooling EUIMilk Cooling EUI

• Energy Utilization Index(EUI)

ilk li (k h/ l d)• Milk Cooling EUI (kWh/cwt cooled)– Conventional cooling 1.2 to 0.8– Well water pre‐cooler  0.9 to 0.6– Pre‐cooler with Milk Pump VFD 0.7 to 0.4

Variable Speed Milk Pump DriveVariable Speed Milk Pump Drive

Variable Speed Milk Pump

• An accessory to a pre‐cooler / heat exchanger

• Ramps milk pump speed up/down to maintain milk level in receiver jar

• Slows milk flow which increases water:milk ratio – More cooling of the milk in the pre‐cooler– Reduced compressor run time / less electricity used

• Increase cooling = more water use w/ VS milk pump

• Replaces standard On/Off Liquid level controller�

Plate Cooler Water VolumePlate Cooler Water Volume

• About 1.25 gallons of water/gallon of milk cooled

lk lb f lk/d ll• 150 Milk cows – 60 lb of milk/day – 1050 gallons

• 1047 X 1.25 = 1309 gallons water / day

• Discharge to waste or reuse?• Discharge to waste or reuse?

Plate Cooler Water Re‐use

• Livestock water

Plate Cooler Water Re use

• Livestock water• Cattle prefer warmed drinking water• Cows will drink more water if it is warmed• Cows will drink more water if it is warmed• Milk production increase• Prevents wastePrevents waste

Milk Cooling Equipment

Compressor + Condenser + Controls =

Milk Cooling Equipment

Compressor + Condenser + Controls = 

Condensing Unit

Milk Cooling Equipment

•Compressors

Milk Cooling Equipment

•Compressors

•Reciprocating are common•Hermetically sealed•Hermetically sealed

•Accessible hermetic

Milk Cooling Equipment

•Scroll Compressors standard with most new systems.

g q p

•Higher efficiency – 15‐20% more efficient than reciprocating types

•Lower noise levels•Reduced vibration•Shorter run time

Milk Cooling Equipment

•Condensers

Milk Cooling Equipment

•Air‐cooled•Water‐cooled

•Water better carrier of heat than air

Compressor LocationCompressor Location

Water Heating

Comprises approximately 

20% of Dairy Energy Usagey gy g

Water Heating

•Conventional Water Heaters•Commercial or Residential Units

•80% efficient new•Age & condition – 70%

Water Heating

•Energy Conservation Measures (ECM)

•Higher efficiency water heaters•Higher‐efficiency water heaters•On‐demand water heaters•Piping insulation•Piping insulation•Preheating the water•Milk Cooling heat recovery systems•Milk Cooling heat recovery systems

W t H tiWater Heating

•High‐efficiency water heatersHigh‐efficiency water heaters

•91% to 95% efficiencies

Water Heater ECMWater Heater ECM

• Existing heater @ 75% efficiencyg @ y

• Replace with high‐efficiency (95%) water heater

• Can realize savings of $400 ‐ $500 per yearCan realize savings of $400  $500 per year

Water Heating

•On‐demand water heaters•Tankless water heaters

Water HeatingWater Heating

•Piping insulationMi i i h•Minimizes hot water temperature losses

Usage(gal/day)

Run Time (hrs/day)

Water Temp. (0F)

Ambient Temp. (0F)

Pipe Size (in.)

Length (ft)

Cost ($/lf)

Savings ($/yr)

CostPayback (years)

185 2 170 65 0.5 25 $0.50 $25 $12.50 0.5

Pre‐Heater Options

•Biomass boilers

•Heat Recovery Units

Pre‐Heater Options•Biomass boilers

Pre Heater Options

•Wood

•Wood Pellets

•Corn

Heat Recovery

• Pre‐heat hot water

Heat Recovery

Pre heat hot water

• 50°F well water

• “Capture” 20 – 50% of heat from    condensing units

• Preheat water to 120°F (50°C)

• +70°F  over well water (50°F)

• Water Heater to 165°F to 185°F

Pre‐Heater ECMHot water out to hot water heater

Pre Heater ECM

CompressorCondenser

Heat Recovery Tank

Compressor Condenser

Cold water in

•On‐demand capability enhanced with pre‐heater•Capable of 6 gpm with 65°F rise 

Water Heating

Usage (Btu/day)

Energy (MMBtu/yr)

Energy (kWh/yr)

LP (gal/yr)

LP Cost @ $1.50/gal

Installed Cost

Payback (yrs)

On‐demand 324,966 118.6 34,765 1,299 $1,949 

+ Pre‐heater 162,498 59.3 17,383 650 $975  $3,000  3.1, , $ $ ,

Fast Payback on Variable Speed Vacuum System

Variable Speed Vacuum PumpVariable Speed Vacuum Pump• Regulates vacuum level by adjusting motor speed i t d f d itti iinstead of admitting air

• Does not run full speed all the timeR d i d• Reduces pump noise and wear

• Reduces electricity consumption up to 50%T i• Two options– New unitVariable frequency drive for retrofit– Variable frequency drive for retrofit

• Requires 3‐phase power – converter available

LightingLighting 

• Options• Options– Incandescent

H l– Halogen

– Fluorescent

– Metal Halide

– High Pressure Sodium

– Light Emitting Diode

General Characteristics f hof Light Sources

Lamp Type Size ‐Watts Efficiency Life (Hr)Incandescent 25‐200 11‐20 750‐5,000H l 50 150 18 25 2 000 3 000Halogen 50‐150 18‐25 2,000‐3,000Fluorescent T8 (4 ft) 32 88 20,000Fluorescent T5 (4 ft) 28 104 20,000Fl ores ent T5 HO (4 ft) 54 93 20 000Fluorescent T5 HO (4 ft) 54 93 20,000Compact Fluorescent 5‐57 50‐80 10,000Metal Halide 35‐70

40060‐94 7,500‐10,000 

20 000400 20,000High Pressure Sodium 35‐400 63‐125 15,000‐24,000Light Emitting Diode 1.2‐1.4 16‐53 60,000‐100,000

Advantages of Fluorescent LightAdvantages of Fluorescent Light

• Very energy efficient compared to incandescent – Conversion to fluorescent will reduce energy usage by up to 75%

• Long life cycleLong life cycle

Ad t f HID Li htiAdvantages of HID LightingMetal Halide ‐ High Pressure Sodiumg

• Increased efficiency compared to• Increased efficiency compared to incandescent

• Fewer fixtures required to provide same level of lightof light

Long‐ Day LightingLong Day Lighting

• During winter cows respond to shorter daylight hours by reducing feed consumption

• Long‐day lighting (16‐18 hours of light) increases milk production by simulating summer conditions

• Can boost milk production 5‐16%p %

• Photocells can be used to regulate long‐day lightinglighting

FansFans

• All fans are not created equalAll fans are not created equal

• HE fans ~ 20% higher energy efficiency

Things That Affect AirflowThings That Affect Airflow

G d• Guards

• Blade design

• Gap between blade tip and housing

• Shape of entranceShape of entrance

• Motor location

S d• Speed

High Volume Low Speed FansHigh Volume Low Speed Fans

• Uses 2 HP per HVLS fanUses 2 HP per HVLS fan

• Savings = 4.3 kW  per hour ofper hour of operation                                                 compared tocompared to                                                moving the same                                                  air volume withair volume with                                                   48” fans

WaterersWaterers

Solar Fence ChargersSolar Fence Chargers

Energy Conservation on Dairy Farms

Ted Probert

Regional Dairy Specialist