Finding and funding refrigeration energy savings with government support Michael Bellstedt , Minus40 Pty Ltd

1. Finding and funding refrigeration energy savings with government support Michael Bellstedt, Minus40 Pty Ltd

2. Contents • Industrial vs Commercial refrigeration • Understanding where power is used • Some bad examples • Industrial refrigeration – energy savings opportunities • Commercial refrigeration – energy savings opps • Funding and finance for energy savings • CTIP program

3. Contents • Industrial vs Commercial refrigeration • Understanding where power is used • Some bad examples • Industrial refrigeration – energy savings opportunities • Commercial refrigeration – energy savings opps • Funding and finance for energy savings • CTIP program

4. Ammonia Our two-sided industry Freon

5. Upgrade to ammonia if you can!!! Ammonia, evaporative condenser, liquid recirculated R404a systems 30-70% LESS efficient R404a, air-cooled condenser, direct expansion

6. Contents • Industrial vs Commercial refrigeration • Understanding where power is used • Some bad examples • Industrial refrigeration – energy savings opportunities • Commercial refrigeration – energy savings opps • Funding and finance for energy savings • CTIP program

7. Where is the energy used? Compressor Air cooler Cooling tower Heat exchangers Pump Pump Expansion device

8. Plant behaviour under all conditions • A well designed refrigeration system will • Run at high efficiency under full cooling load • Use LESS power during cool weather • Use LESS power when the cooling load is reduced • Many existing refrigeration systems do NOT behave this way, or not sufficiently • So we need to modify/upgrade the systems to make them do this

9. Typical techniques • Making plant more efficient at full load (less peak demand) • Replace deteriorated condensers • Check refrigerant charge • Clean condensers and evaporators • Improve cool air flow to condensers • Making the plant more efficient at low load (less power consumption) • Fit VSDs to compressors and fans, or use EC fans • Upgrade plant controls to run the plant smarter • Making the plant more efficient in cool weather (less power consumption) • Fit electronic expansion valves • Float head pressures • Reducing the load on the plant (less power consumption and peak demand) • Improve insulation, check door seals, fit quick acting doors, etc • Optimise defrost cycles • Smart lighting in cool/freezer rooms

10. Contents • Industrial vs Commercial refrigeration • Understanding where power is used • Some bad examples • Industrial refrigeration – energy savings opportunities • Commercial refrigeration – energy savings opps • Funding and finance for energy savings • CTIP program

11. Poor insulation Saturated insulation Home-made!

12. Dirty / corroded evaporator coils Blocked or deteriorated coils do not transfer heat well. Suction temperatures must be reduced to maintain coil performance Reducing coil temperature by 3ºC increases power use by 10% Clean/replace evaporators

13. Mains water sprayed onto condenser Water sprays on air cooled condensers are a SHORT TERM fix Chlorine in water quickly corrodes aluminium fins Water needs to be fully atomised Corrosion reduces air flow and reduces heat transfer capability A short term power savings can turn into a long term power penalty

14. Contents • Industrial vs Commercial refrigeration • Understanding where power is used • Some bad examples • Industrial refrigeration – energy savings opportunities • Commercial refrigeration – energy savings opps • Funding and finance for energy savings • CTIP program

15. Common energy savings strategies • Variable head pressure control • Compressor speed and staging control • High efficiency motors on compressors and pumps • Screw compressor economisers • Variable fan speed control • Heat recovery • Bottleneck removal

16. Variable speed drives (VSDs)Fan savings • 10kW fan motor • Run fan 50% of the time = 5kW average use • Run fan at 50% fan speed =1.25kW average use • Save 3.75 kW = $5,000/annum • 10kW VSD costs <<$5,000!!!

17. Variable head pressure control / condenser fan speed control • Head pressure setpoint depending on load and ambient conditions • Significant savings at: • Cool Ambient Conditions • Part Load VSDs on condensers Temperature/Humidity sensor

18. Compressor speed and staging control • Unloading via Speed Control rather than Slide Valve • VSD’s on Compressors • Appropriate Control Logic

19. Economisers on Screw compressors • Sub-cooling receiver liquid • Improved efficiency (5-10%) • Increase in compressor capacity (3-8%) • Needs VSD on compressor Economiser vessel Eco port connection

20. Liquid injection oil cooling on screw compressors • Problem: LI oil • cooling reduces efficiency • Solution: Water cooled • oil cooling

21. Economizer on screw compressor

22. High efficiency motors • Older motors (pre 1990) generally low efficiency • Modern motors >95% efficient • Savings up to 10% possible • 2-3% loss with every re-wind!! • Match with VSD NEW OLD

23. Heat recovery • Freezer room subfloor heating (<20ºC) • Domestic Hot Water/ Hand wash (40ºC) • Space heating (40-60ºC) • Washdown water (55-60ºC) • CIP, sterilisation (80-90ºC) • Boiler feedwater (any)

24. Heat recovery with high stage desuperheater

25. Typical “Bottlenecks” • Undersized evaporators/condensers • Decreases suction, increases condensing temp • Direct expansion evaporators • Limits variable head pressure control options • Excessively long wet/dry suction lines • Reduces suction pressure at compressor • Poorly designed wet suction risers • Reduces suction pressure at compressor • Undersized suction/discharge lines, or unnecessary line obstructions • Reduces suction, increases discharge pressure at compressor • Redundant suction regulation valves • Reduces suction pressure at compressor

26. Example: Poor suction line installation Two stop valves in series!! Redundant valve not removed from suction line

27. Contents • Industrial vs Commercial refrigeration • Understanding where power is used • Some bad examples • Industrial refrigeration – energy savings opportunities • Commercial refrigeration – energy savings opps • Funding and finance for energy savings • CTIP program

28. Adiabatic pre-coolers on condensers Pre-cool condenser inlet air by evaporating water Either as mist spray or with wet pad Do NOT wet the coil surface

29. EC Evaporator and condenser fans Electronically Commutated (EC) motor fans save considerable amounts of power compared to conventional fans Speed control very easily done Fan speeds can be controlled to suit the load – lower speeds when set-point temperatures have been reached Fan power savings >>80% possible

30. Electronic Expansion Valves • Thermostatic Expansion (TX) valves used as standard • Low cost, but • Do not fully utilise evaporator surface area • Require high liquid pressure at all times = high head pressure • Electronic Expansion valves allow systems to run at lower liquid pressure = lower power consumption • 5ºC lower condensing temperature = 15% power saving • CONSUMPTION saving! • But does not necessarily reduce power consumption during summer peak conditions

31. Water cooling Air-cooling most commonly used in commercial refrigeration Convenient, generally low maintenance But, during hot weather condensing temperatures can be very high, resulting in high peak power use. Major cause for high power DEMAND costs!!! Using cooling tower + water cooled condenser will substantially reduce summer peak power, and therefore demand costs DEMAND savings of 30-40% typical Disadvantage: Water treatment costs! But: Where the site already has a cooling water system, using water cooling makes sense

32. Oversized (or Low TD) condensers • Industry standard is “14KTD” • Therefore at 30ºC ambient temperature, the refrigerant will condenser at 44ºC • With larger (and more costly) condensers this can be reduced to 5-10 “KTD”. • At 5KTD, the system will use 25-35% less power!! • Potential for DEMAND and CONSUMPTION saving

33. High efficiency condensing units • Single compressor condensing units available with • On-board VSD for compressor • Variable speed condenser fans • Advanced controls • Advantages • Better control of head pressure • Less or no compressor cycling • Optimum suction pressures

34. Carbon Dioxide systems • CO2, or R744, is already widely used in supermarket applications • Wide range of system designs, including • Cascade • Transcritical • Compound • Volatile secondary • Main application for LT systems • Development of small CO2 package units underway • Reduces or eliminates HFC refrigerants • Significant energy savings possible, depending on design/application

35. Mini-chillers + glycol systems for MT • Most commercial refrigeration systems use DX evaporators and extensive refrigerant piping • Disadvantages: • High efficiency losses due to pressure drops • High refrigerant charge (generally HFCs) • New technology: • Small air/water cooled compact high-efficiency chillers to provide chilled glycol • Glycol reticulation system • Medium temperature air coolers on glycol • Glycol-cooled CO2 systems for freezer rooms • Advantages: • Low refrigerant charge • Low refrigerant leakage risk • Simple and reliable • Considerable DEMAND and CONSUMPTION savings possible

36. Glycol defrost on CO2 coils • Most commercial refrigeration systems use electric defrost • Defrost heaters are prone to failure and use considerable amounts of electric power. • Hot-gas or water defrost more efficient, but higher cost • CO2 refrigeration units are ideal for heat recovery. • Hot glycol storage tank constantly re-heated with recovered heat. • CO2 evaporator coils built with interlaced glycol circuit. • During defrost, glycol circulated through coil until ice removed. • Considerable DEMAND and CONSUMPTION savings Diagram Courtesy: Strathbrook Industrial Services

37. Quick “low cost” CR fixes • Check refrigerant charge • Clean condenser and evaporator coils • Check temperature sensors (ice-bath) • Improve cool air flow to condensers • Check/replace cool/freezer room door seals, • Optimise defrost cycles • Timer/motion detectors on cool/freezer room lighting • Relocate liquid line solenoid located on condensing unit

38. Contents • Industrial vs Commercial refrigeration • Understanding where power is used • Some bad examples • Industrial refrigeration – energy savings opportunities • Commercial refrigeration – energy savings opps • Funding and finance for energy savings • CTIP program

39. Government programs and examples • NSW Energy Saver Program • NSW Energy Saving Scheme • Low Carbon Australia • Clean Technology Investment Program • Case study 1: NSW-based processor • Case study 2: Non- NSW-based processor

40. NSW Energy Saver Program • 50-80% subsidy for Energy Audit • 30 hours engineering support for implementation Limitations: • NSW sites only • Not applicable to EEO (very large!) companies • Suitable for sites spending $60K+ p.a. on electricity

41. NSW Energy Saving Scheme • Energy Savings Certificates [ESCs] created for energy savings projects. • ESCs can be traded for CASH • Typical $50k Energy Efficiency project can attract ESCsworth $1,000 to $3,000 Limitations: • NSW only, all sites

42. Low Carbon Australia • Low Interest Finance for Energy Savings projects • Operational Leases • Financial Leases • On-power-bill financing • Direct loans Limitations: • All sites in Australia • Not applicable to greenfield sites • Must satisfy carbon reduction criteria

43. Clean Technology Investment Program • 33% or 50% of capital cost of Energy Efficiency project as GRANT (Grants < $10M) Site gets: • 50%, if company turnover <$100M and requested funding <$500,000 • 33%, for all other grants up to $10M Limitations: • All sites in Australia • Manufacturing industry only (including food)

44. Case Study1: NSW meat processor – ABC Pty Ltd • ABC’s production site uses 1GWh of power per annum, costing $150,000 per annum • The site conducts an Energy Saver audit subsidized by the OEH • The study identifies a $100,000 refrigeration plant project saving $20,000 power per annum, 5.0 year simple payback. • Further engineering costs are applied to fully scope the project • ABC applies for a loan from Low Carbon Australia (up to 50%), repayable over 5 years • ABC obtains a capital grant from the Clean Technology Investment Program

45. Case study 1: NSW meat processor – ABC Pty Ltd Overall project result

46. Case Study 2: Non- NSW meat processor – XYZ Pty Ltd • XYZ’s production site uses 1GWh of power per annum, costing $150,000 per annum • The site conducts an energy audit • The study identifies a $100,000 refrigeration plant project saving $20,000 power per annum, 5.0 year simple payback. • Further engineering costs are applied to fully scope the project • ABC applies for a loan from Low Carbon Australia (up to 50%), repayable over 5 years • ABC obtains a capital grant from the Clean Technology Investment Program

47. Case study 2: Non- NSW meat processor – XYZ Pty Ltd Overall project result

48. Contents • Industrial vs Commercial refrigeration • Understanding where power is used • Some bad examples • Industrial refrigeration – energy savings opportunities • Commercial refrigeration – energy savings opps • Funding and finance for energy savings • CTIP program

49. Minus40 CTIP successes to date

50. CTIP process • Overview of entire process • Understanding Merit Criteria • Energy baseline determination