$1.9-2.0M (USD 1.9–2.0 million)

The figure of USD 1.9-2.0 million is an indicative capital cost benchmark commonly cited in pre-feasibility material for a small commercial CBG plant in India — typically a plant producing in the range of 1-3 tonnes per day of CBG (roughly 100-300 m³/hr of upgraded biomethane). At the exchange rate of approximately ₹83-85 per USD, this corresponds to ₹15.8-17 crore in INR terms, consistent with the lower end of the 5 TPD plant cost band that appears in SATAT and MNRE programme documents.

The capital build-up behind this number breaks down approximately as follows. Digester and upgrading skid (35-45%): CSTR digesters of 1,500-3,000 m³ working volume, gas holders, biogas upgrading by water scrubbing or membrane separation, gas booster and conditioning. Civil and structural works (15-20%): digester foundations, slurry pits, control room, security and approach roads. Pretreatment line (10-12%): shredders, magnetic separators, mixing tanks, pumps. Compression and storage (8-10%): 200-bar CNG-style compressors, cascade storage cylinders. Utilities, electricals, piping, instrumentation (12-15%). Pre-operative, statutory, contingency (5-8%).

The figure should be read with three caveats. First, it excludes land cost, which can add ₹40 lakh to ₹2 crore per acre depending on location. Second, it excludes working capital and interest during construction, which together can add 12-18% to the total initial investment. Third, the range reflects vendor mix and technology choice — water scrubbing upgrading is cheaper than membrane or amine, Indian fabrication is cheaper than European, and BS-VI-grade dispensing equipment adds 8-12%.

For investors, the USD 1.9-2.0M benchmark functions as a quick sanity check. A small CBG project whose DPR shows CAPEX significantly below this should be scrutinised for under-specified pretreatment or undersized upgrading; one significantly above should be checked for over-engineering, gold-plating or scope creep. Comparing against actual ratecards from at least two vendors and one operating Indian peer plant of comparable scale is the prudent next step before equity commitment.