Can a voltage stabiliser cut a rice mill's electricity use?

It protects motors on a weak supply, but do not bank on the kWh. BEE's Ganjam report claims 9,503 kWh a year from a 75 kVA stabiliser on a 2 TPH mill, Rs 0.40 lakh, payback 2.63 years. That figure treats the whole load as a loss. Meter the mill with and without it before you count any saving.

The problem is real

Ganjam mills draw power through shared distribution transformers that are smaller than the load. BEE measured 270 to 350 volts against 415 needed, and about 30% of mills face acute low voltage. Motors pull more current, windings overheat and burn, and owners run only part of the line, so motors sit lightly loaded. A stabiliser holds the output at 415 volts within 1%.

What the report claims

• Mill: 2 TPH, 14 hours a day for 340 days, 95,000 kWh a year, 14.1 kWh a tonne.
• Measured: 360 volts, 22.4 amps, power factor 0.67.
• Claim: raising the voltage to 415 cuts current to 19.43 amps and saves 2 kW, so 2 x 14 x 340 = about 9,503 kWh a year, 10% of the mill's power.
• Cost: stabiliser Rs 1.00 lakh after discount, plus Rs 0.05 lakh fitting. Saving Rs 0.40 lakh at Rs 4.20 a kWh. Payback 1.05 / 0.40 = 2.63 years.

Why the kWh figure does not hold

• The report's 'loss' of 8.06 kW is 360 volts x 22.4 amps: the circuit's whole draw, not a loss.
• It then assumes the same power at higher voltage and the same resistance. Both cannot be true, so the 2 kW cut is an artefact of the sum.
• Higher voltage does cut current and the heat lost in cables and windings, but that is a small share of the power, and a stabiliser has losses of its own.
• The report also gives two CO2 figures, 7 t and 9 t, for the same saving.

When it is still worth buying

1. Count the motors rewound in the last two years and their cost. Fewer burnouts is the solid return.
2. Ask the discom about a dedicated or larger transformer; it fixes the cause.
3. If you fit a stabiliser, log kWh per tonne for a month with it bypassed and a month in service, at similar output.

What the claim would be worth if it held

• 9,503 kWh x 0.675 = 6.4 t CO2 a year
• Share of the mill's power: 9,503 / 95,000 = 10%
• The report says 7 t in its summary and 9 t in the body

CO2 at CEA's FY 2025-26 grid factor of 0.675 kg per kWh. Shown only to correct the report's figure, not as an expected saving.

What Senseible does here

Senseible's calculators turn measured kWh into CO2 on the current grid factor, and it reads monthly electricity bills into records, so a month bypassed and a month in service can be compared bill against bill.

• Carbon calculators
• Voltage optimisers and servo stabilisers
• Ganjam rice mills: power records that pay
• Rice mill improved paddy cleaner

Sources: BEE, Detailed project report: voltage stabiliser 75 kVA, Ganjam rice mill cluster (SAMEEEKSHA), CEA CO2 Baseline Database, version 22.0

Last reviewed 2026-11-01. Report figures are from a BEE SME programme project report; costs and paybacks are at the report year's prices. Check today's tariff and a current quote.