Packhouse Action Group Water and Energy Project

2021 Energy Benchmark Results

February 2023

Table of Contents

1. Introduction
2. Methodology
   • 2.1 Development of the Data Collection Tool
   • 2.2 Scope of the Data Collection
   • 2.3 Participation
   • 2.4 Notes on the Data
3. Electricity Benchmarks
   • 3.1 Packhouse Operations
     • 3.1.1 Calculation
     • 3.1.2 Results
   • 3.2 CA Operations
     • 3.2.1 Calculation
     • 3.2.2 Results
   • 3.3 RA Operations
     • 3.3.1 Calculation
     • 3.3.2 Results
4. Overall Packhouse Electricity Consumption Index
5. Electricity Sources
6. Electricity Usage Profile
   • 6.1 Variation in Electricity Use Profiles
7. Electricity Cost
8. Year-on-Year Energy Comparison
9. Energy Management Practices
   • 9.1 Pre-sort/Packing Line
   • 9.2 Refrigeration
   • 9.3 Ablutions, Canteens and Offices
   • 9.4 Additional Energy-Saving Practices
10. Conclusion
11. Recommendations

Introduction

In 2021, Blue North Sustainability was contracted by the Packhouse Action Group (PAG) to benchmark the electricity consumption in pome fruit packhouse and cold storage operations (2020 data). This report is the second round of electricity benchmarks (2021 data). The objectives were to:

• Replicate the electricity use benchmark study from Phase 1 (2020 data)
• Provide a year-on-year comparison of electricity use in packhouse and cold storage operations
• Identify and compare energy management practices applied
• Encourage industry knowledge sharing

This report presents the results of electricity use benchmarks from January to December 2021 and summarises the different energy management methodologies applied at the packhouses.

Methodology

Outreach was done to potential new participants via phone or email, offering project details and a virtual onboarding session. Previous participants were offered training in the latest version of the data collection tool if needed.

2.1 Development of the Data Collection Tool

• Additional data capture fields for generator electricity use and fuel cost
• Additional data capture fields for renewable energy financing cost
• Data was sense-checked and anomalies discussed with participants

2.2 Scope of the Data Collection

Three areas in pome fruit packhouses were benchmarked for electricity consumption:

• Packhouse operations: All operational electricity (pre-sort, packing lines, ablutions, canteens, offices)
• Controlled Atmosphere (CA) operations: All electricity relevant only to CA operations (refrigeration plant, compressors, condensers, fans, cooling towers, etc.)
• Regulated Atmosphere (RA) operations: All electricity relevant only to RA operations (refrigeration plants, compressors, condensers, fans, cooling towers, etc.)

2.3 Participation

• 21 packhouses contacted; 9 provided data
  • 8 of these also participated in Phase 1
  • 3 more showed interest for future rounds

2.4 Notes on the Data

• All data sets refer to the 2021 calendar year (January to December)
• All kWh figures include grid, PV, and generator electricity
• Packhouses are anonymised (A to M)
  • Packhouse F: only total grid electricity consumption
  • Packhouse K: only total energy consumption and cost
• Caveats are acknowledged in the report
• In figures: blue bars = accurate/metered data; yellow bars = estimated/calculated data

Electricity Benchmarks

3.1 Packhouse Operations

3.1.1 Calculation

Packhouse operations electricity consumption (kWh) / Tonnes of pome fruit packed

Unit: kWh per tonne of pome fruit packed

3.1.2 Results

• Only packhouses that provided data are shown
• Electricity consumption for packhouse operations ranged from 21–33 kWh per tonne (metered data)
• This aligns with the benchmark of 15–44 kWh/ton found in Bouwer (2011)
• Variation may be due to different energy management practices

Examples:

• Packhouse A: switches off most lights during breaks (day/night shifts)
• Packhouse B: energy-efficient motors and LED lighting
• Packhouse C: low-consumption LED lighting, phase-balancing systems
• Packhouse H: LED lighting, staff trained on energy saving, skylight panels
• Packhouse M: soft starters and energy-saving lights
• Packhouse D & L: no energy-saving practices indicated

3.2 CA Operations

3.2.1 Calculation

CA operations electricity consumption (kWh) / CA Tonne.Days

Unit: kWh per Tonne.Day of fruit stored

• Tonne.Days = Tonnes stored × number of days stored

3.2.2 Results

• Only packhouses with data shown
• Metered/accurate data: CA operations benchmarks ranged from 0.3–1.9 kWh per Tonne.Day
• Aligns with Bouwer (2014): <1 kWh per Tonne.Day for CA storage of apples

Examples:

• Packhouse A: VSDs on most CA/RA fans, PLC-controlled condensers/fans/lights, lights off during breaks
• Packhouse B: solar panels for refrigeration (solar kWh included)
• Packhouse C: VSDs on all major compressors
• Packhouse D: auto-scheduling based on RURAFLEX peak tariff, energy management on cold stores
• Packhouse M: combines underutilised cold rooms to save energy

3.3 RA Operations

3.3.1 Calculation

RA operations electricity consumption (kWh) / RA Tonne.Days

Unit: kWh per Tonne.Day of fruit stored

3.3.2 Results

• Metered data: RA operations benchmark between 3.0–6.1 kWh per Tonne.Day
• Lower than the 8 kWh benchmark for apples in Bouwer (2014)
• Variation attributed to different energy management practices

Overall Packhouse Electricity Consumption Index

• Incorporates electricity use for all sections except “other”
• Unit: kWh per tonne of pome fruit packed
• Most packhouses consumed 150–250 kWh per tonne in 2021
• Variation due to unique facility combinations, CA storage capacities, and management practices

Electricity Sources

• Over 80% of electricity used is supplied by the grid (e.g., Eskom)
• Five packhouses also use solar (PV) energy

Electricity Usage Profile

• Compares percentage of electricity consumed by different areas/activities per packhouse (excluding “other”)
• Packhouses A, B, D, and M provided accurate data

Table 1: Summary of Packhouse Data Quality

6.1 Variation in Electricity Use Profiles

Large variances attributed to:

• Lack of metering (estimated data)
• Metered consumption not allocated to specific areas
• Errors in records
• Different energy management practices
• Different CA storage capacities and strategies

Electricity Cost

• Grid electricity cost per kWh for 2021: R1.30–R1.80 (up from R1.00–R1.70 in 2020)
• Increase mainly due to Eskom’s 15% tariff hike in 2021

Table 2: Quality of Cost Data (Rands) per Electricity Source

• Renewable electricity (PV) had the lowest cost; generator electricity the highest
• Generators are increasingly relied upon due to load shedding, raising costs
• Recommendation: Explore renewable energy and battery solutions for long-term savings

Year-on-Year Energy Comparison

• Only packhouses participating in both Phase 1 and Phase 2 are shown
• 2021 energy consumption per ton of fruit packed decreased for most packhouses compared to 2020
• Another year’s benchmarking would confirm if this is a trend

Energy Management Practices

9.1 Pre-sort/Packing Line

• Six packhouses apply energy management practices:
  • Switching off lights during breaks
  • LED lights
  • Phase balancing systems
  • Variable Speed Drives (VSD) and PLCs
  • Soft starters

9.2 Refrigeration

• Seven packhouses apply energy management practices:
  • VSD motors on compressors/fans
  • PLC programs for condensers
  • SCADA systems for semi-automatic control
  • Soft starters on condensers
  • Solar energy for cold storage
  • Auto-scheduling based on RURAFLEX peak tariff
  • High-speed doors on RA rooms
  • Combining underutilised cold rooms

9.3 Ablutions, Canteens and Offices

• Four packhouses apply energy management practices:
  • Switching off hot water boilers over weekends
  • LED lights in staff facilities
  • Motion sensors on office lights

9.4 Additional Energy-Saving Practices

• Switching off glue machines over weekends
• 500 kVA solar panels for packhouses and cooling facilities (expansion planned)
• Lithium-ion forklift batteries
• Staff training on energy-saving awareness; skylight roof panels for natural light
• Power Factor Correction, 1 MW solar installation, absolute energy monitoring, energy-efficient motors, LED lighting, CAPEX installations, solar power with backup generator
• Switching plant room off whenever possible

Conclusion

• Seven packhouses from Phase 1 returned for Phase 2, indicating value in the process
• The project provides valuable insights and a baseline for improvement and target setting
• Collection of generator electricity use, fuel, and renewable energy financing costs improves accuracy
• Efficient equipment and good management practices can greatly improve energy use efficiency
• Most participating packhouses have energy management practices in place and some are expanding solar capability

Areas of concern:

• Some packhouses do not meter electricity use in specific areas, limiting understanding of consumption patterns
• In some cases, meters are not read or readings not recorded, undermining data quality and management decisions

Positive trends:

• Energy consumption appears to be decreasing over time
• Continued annual studies will help confirm year-on-year trends

Recommendations

• Understand reasons for metering issues; collect this data in future rounds
• Ask packhouses for suggestions to improve the data collection tool and processes
• Continue collecting annual data to confirm the downward energy consumption trend
• Where possible, collect cost and kWh savings achieved from energy management practices
• Collect more detail on how renewable energy cost is determined (e.g., financing, capital repaid, repairs, maintenance)