Oomiak has recently completed the design, installation and commissioning of control works to deliver semi-automated electrical load shedding for refrigeration plants across three major cold store sites in Australia.
For a typical cold store up to 85% of electricity usage on site is consumed by the refrigeration plant, which makes this area a prime target for energy efficiency improvements.
Oomiak implemented an automatic energy management control to load shedding regime based on a set of predetermined criteria:
- Rooms sequence selected for shedding
- Actual room operating temperature vs set point
- Maximum acceptable temperature in rooms
- Ambient temperatures
- Time of day – based around tariff rates and rate changes
- Prevailing tariff spot rate
- Maximum demand cost
Using real time data, the shedding control strategy reduce operational electrical power consumption by:
- Peak tariff load reduction – Direct load shedding by shutting down part or all of the none critical loads during peak tariff rates and by shutting down cooling to rooms based on current operating temperatures (acceptable ranges)
- Maximum demand control – Limiting maximum demand at all times by limiting / preventing compressor loading
Early results have been very impressive and it is expected these control changes will bring about a significant reduction in power consumed over the long run.