Should a seafood plant swap to screw compressors or to an ammonia and carbon dioxide system?

The Energy and Resources Institute (TERI) seafood profiles put screw compressors at 10 to 20% less specific power than reciprocating ones, for about rupees (Rs) 2.0 to 2.5 million and a 1.5 to 2 year payback. A full ammonia and carbon dioxide system saves about 35% but costs Rs 30 to 40 million, payback 5 to 6 years.

The two options as TERI states them

• Screw compressor in place of reciprocating: specific power consumption about 10 to 20% lower. Investment for a typical facility about Rs 2.0 to 2.5 million. Simple payback 1.5 to 2 years.
• Ammonia and carbon dioxide system: ammonia is kept out of the process area and a secondary carbon dioxide circuit carries the heat. Energy saving about 35%. Investment for a typical facility about Rs 30 to 40 million. Simple payback 5 to 6 years.
• The Veraval and Bhubaneswar profiles give the same figures. Both describe plants running reciprocating compressors on ammonia, and both note that ammonia is toxic.

What the profiles do not say

They do not state which energy the percentages apply to, or how big the "typical facility" is. Our reading is that they apply to refrigeration power. The Veraval profile puts refrigeration drives at about 80% of a plant's electricity. Check the base before you quote a percentage to a lender.

Which to pick first

• The screw compressor is the cheaper step and pays back in 1.5 to 2 years on the profile's numbers.
• The ammonia and carbon dioxide system replaces the whole refrigeration system, with a payback of 5 to 6 years on the same numbers.
• In both cases the carbon gain shows up as kilowatt hours on your bills.

The 3,000 tonne a year Veraval plant, financial year (FY) 2025-26 grid factor (example)

• Plant electricity in the profile: 3,168,760 kilowatt hours (kWh) a year
• Refrigeration share at 80%: 2,535,008 kWh
• Screw compressors at 10%: 253,501 kWh, at 20%: 507,002 kWh. At 0.675 kg of carbon dioxide (CO2) per kWh that is about 171 tonnes to 342 tonnes a year
• Ammonia and carbon dioxide system at 35%: 887,253 kWh, about 599 tonnes of CO2 a year
• If 35% applied to all electricity instead: 1,109,066 kWh, about 749 tonnes. That is the ceiling, not the likely figure

The 80% base is our reading, as set out above. Plant electricity is from the profile; the percentages are TERI's. Measure your own compressor load before you decide.

What Senseible does here

Senseible reads fuel invoices and electricity bills into monthly records, so a plant can see its yearly electricity and the month-by-month change after an upgrade. It does not size compressors or confirm the saving a supplier promises.

• Veraval seafood cluster: energy and CO2
• Ammonia against hydrofluorocarbon (HFC) cold storage
• Kochi seafood freezer energy and carbon
• Green loan readiness check

Sources: Cluster profile of Veraval seafood processing industries, The Energy and Resources Institute (option v), Cluster profile of Odisha (Bhubaneswar) seafood processing industries, The Energy and Resources Institute (option v), Central Electricity Authority (CEA), CO2 Baseline Database for the Indian Power Sector, version 22.0 (0.675 kg CO2 per kWh, FY 2025-26)

Last reviewed 2026-11-06. Costs are in the profiles' own rupee figures from 2015 to 2017. Get a current quote.