K Hartman

1
Dairy Insight Project IIOn Farm Energy Savings

• K Hartman Ralph E H Sims
• Centre for Energy Research,
• Massey University, Palmerston NorthR.E.Sims_at_masse
  y.ac.nz
• Karl_at_dews.co.nz

2
Why Peak Reduction?
10,000/MWh 10/kWh 1/hd
3.85 million head 100w/hd 385 MW peak
3
The Big Question

• How can I save energy?

• 2 sides of the savings coin
• Conserve energy
• Reduce costs

4
Finding the Answer

• Where is energy used on the farm
• How much am I using
• Where can I conserve energy
• How can I reduce energy costs
• Case studies
• Almost there
• What if
• Further assistance

5
Where is Energy Used on the Farm
Barrie, 2005
Proportion of energy inputs on the average farm
surveyed
6
Survey Results kWh/day vs head
7
Survey Results kWh/hd/day vs head
8
Comparison (kWh/hd/day)
9
How much am I using

• Meridian Energy Calculators
• Full Model
• Mailed out to customers, CD based
• Intensive
• Mini-Calculator
• On-line version (www.meridianenergy.co.nz)
• Simple Model (3-5 minutes)

10
WWW.Meridianenergy.co.nz/yourfarm
11
(No Transcript)
12
(No Transcript)
13
(No Transcript)
14
(No Transcript)
15
(No Transcript)
16
Where can I conserve energy

• Major loads
• Milking Machine (vacuum pump)
• Milk Chilling
• Water Heating
• Irrigation (not on all farms)
• Miscellaneous
• Water and effluent pumping
• Lighting
• Other minor loads (is the kettle major or minor?)

17
Vacuum Pump (non variable speed)

• Constant load
• Fully loaded entire milking cleaning
• Size proportionate to of clusters
• More clusters - larger the load
• Vacuum brakes provide reserve capacity
• Not doing useful work - 0 efficiency

18
Milk Chilling

• Two parts
• Initial cooling of the milk
• Maintaining milk temperature lt4 C (10)
• Pre-cooling
• Plate heat exchanger (35 20 C)
• Dependant on cooling water temperature
• Bore vs surface water

19
Water Heating

• Electric (resistive) heating
• Batch or Continuous heat
• Initial and Maintenance heat (15)

• Centralized thermal power plant
• Fuel electricity heat
• Can be less than 18 efficient at point of use
• 3.5x the primary fuel use than if made onsite
• 4x more heat wasted at power plant than
  developed at point of use

20
Water Heating (B.V)
21
Water Heating (A.V.)
22
Irrigation / Pumping / Other

• Individual farm dependant
• Age/type/condition of pump
• Pumping head (static vs dynamic)
• Saving water saves energy
• Other loads
• Lighting (Natural vs artificial)
• Incandescent Light bulb 2 efficient fuel to
  light

23
How can I reduce energy costs

• Reduce usage
• Waste heat recovery preheat water to cylinder
• Additional milk pre-cooling (1 C 6 cooling
  load)
• Variable speed vacuum pump / pully size
• Reduce vacuum demand ? (10/20/70)
• Load Shifting / Peak Reduction
• /month per kW peak use charge (?)
• Energy Storage (Hot Water, Ice Banks)
• Rate schedules
• Day / Night / Controlled Rates
• Fixed daily charges (higher daily lower per
  unit)

24
Case Study Almost there

• Smaller farm 220 head
• 20 bail herringbone
• Day / Night rate (night 1/3 day rate)
• Timers on water heaters (batch w/pre-heat)
• Ice bank
• Used for morning and afternoon milking
• Pre-cools milk to 4 C into the vat
• Low vacuum demand (4 kW)
• Short milk and vacuum runs
• Enclosed milk vat, uninsulated

25
Cumulative Energy Use (kWh)
26
Case Study What if

• Mid-sized farm 550 head
• 2x 20 bail herringbone pits
• Anytime / Controlled rate
• 15 kW vacuum demand
• 2 hot washes per day
• Uncovered, insulated milk vat
• 15 psi artesian bore
• 27 kW for effluent stir / pumping

27
Total energy use (before)
25
75
28
Hot Water (before)
Vat Wash
System Wash
29
Hot Water (after)
30
Milk Chiller (before)
31
Milk Chilling (after)
32
Vacuum Pump (before)
33
Vacuum Pump (after)
34
Total System (after)
55
45
30 70
Overall 33 energy savings
Overall 50 cost savings
35
Further Assistance

• Dairy Insight Phase II
• Identify energy saving techniques and
  technologies
• Demonstrate on-farm examples
• Getting the word out
• Process-specific information sheets
• Water Heating
• Milk Cooling
• Milking Machine
• Tractor Fuel Use (revisiting Tractor Facts from
  80s)
• Lighting / Other

36
(No Transcript)
37
Review

• Big ticket items in the shed
• Water Heating
• Milk Cooling
• Milking Machine (vacuum pump)
• Fast payback
• Batch hot water vs constant feed
• Day / Night rates
• Timers Lighting / Hot Water
• Minimize water use

38
Future Technologies

• On-site co-generation (biofueled?)
• Wind/Hydro/PV/solar thermal
• Waste-to-energy (AD) systems
• Enhanced thermal storage

39
The Matrix