Tom Osborn - BPA

Results of Spud Onion Shed Efficiency

Projects

Discussion Topics

What is a Spud Shed?

Measurement & Verification Results.

Request for approval of kWh savings per HP

Estimating Savings

Spreadsheet tool

Measure Fan or Pump kW

3 year billing history

Load in / out dates

Estimating Savings

Vendors using spreadsheet tool

Measure Fan or Pump kW

3 year billing history

Load in / out dates

Estimating Savings using spreadsheet

Storage Capacity (ton) 4,000

Storage Capacity (cwt) 80,000

Design Airflow (cfm/ton) 20

Total Fan HP 80

Fan Motor Loading (est) 90%

Fan Motor Efficiency 95%

Calculated Fan Use (kW) 56.5

VFD Efficiency 95%

Total Measured Fan (kW) 60.0

Refrigerated (Yes/No) Yes

Potato and Onion Storage VFD AnalysisProject Name XYZ Potato Shed

Contact Operator 1

Contact Phone No. 509-527-6211

Location Walla Walla, WA 99362

Farm Name Nice Cultivars

Estimating Savings

No VFD (Current) Ventilation System Profile

Storage PhaseStarting Dates

Days

Fans In-Use

Fan Run Time

Calculated Usage Typical Fan Operation

(%) (hr/day) (kWh)

Harvest / Load 9/15/2006 5 100% 10 3,000 Start fans when loading

Cure / Suberize 9/20/2006 5 100% 24 7,200Continuous/Recirc if no OSA

Ramp to Hold Temp 9/25/2006 40 100% 24 57,600 Run Anytime OSA Avail

Winter Holding 11/4/2006 45 100% 24 64,800 Run Anytime OSA Avail

Spring Holding 12/19/2006 99 100% 24 142,560 Run Anytime OSA Avail

Unload 3/28/2007 15 100% 10 9,000Continuous w/ OSA or Refrig

empty 4/12/2007 0 100% 0 0 Run Anytime OSA Avail

Storage Season Length   209   Total = 284,160  

Estimating Savings Estimated VFD Ventilation System Operation Profile

Storage PhaseStarting Dates

Days

Fan Speed

Fan Run Time

Calculated Usage Typical Fan Operation

(%) (hr/day) (kWh)

Harvest / Load 9/15/2006 5 70% 10 1,249 Start fans when loading

Cure / Suberize 9/20/2006 10 100% 24 15,158Continuous/Recirc if no OSA

Ramp to Holding Temp 9/30/2006 40 90% 24 46,103 Run Anytime OSA Avail

Winter Holding 11/9/2006 45 70% 24 26,984 Run Anytime OSA Avail

Spring Holding 12/24/2006 90 80% 24 76,369 Run Anytime OSA Avail

Unload 3/24/2007 15 70% 10 3,748Continuous w/ OSA or Refrig

empty 4/8/2007 0 0% 0 0 Run Anytime OSA Avail

Storage Season Length   205   Total = 169,611  

Estimating Savings

Estimated Energy Savings 114,549

Percent Energy Savings 18% (range 10-30%)

Energy Cost Savings $5,727.47

Estimated Project Cost $16,000.00 ($100-200/HP)

Potential Incentive $9,600.00(may need to adjust formula)

Payback w/o incentive (yr) 2.8

Payback with incentive (yr) 1.1

M&V Savings(results may vary)

Monitor 6 months or an entire season.

Use utility meter, sub meter, or VFD display data.

Monthly records desirable.

43 VFD projects in Spud /Onion Sheds

Spud Shed Savings Percentage

-40%

-20%

0%

20%

40%

60%

80%

100%

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35

Why Different Results?

Crop TypeLoad in & Out Dates

TonnageQuality

Crop OwnerStorage Manager

Storage type (w/ refrigeration?)Analysis Quality

Drive Failure

Vendor Driven Program

-Utilities explained program to vendors and shed operators.

-Generally, suppliers of the shed control system market the utility

program. e.g.

-Suberizer

-Custom Chemical

-JMC Ventilation

-Industrial Ventilation Inc

Results

-43 projects or more!

Average savings of 32%

Average savings 1,255 kWh/HP

Average Cost of $282

Average rebate claimed $129

Summary

Spud Sheds with VFDs can be run more efficiently!

Economics are good.

Product quality can improve.

Savings can vary, but average savings of 32%.

BPA requests approval of savings/HP.

Questions?

Tom Osborn

509-527-6211