Waste Heat Recovery Chillers: How to Calculate ROI for Your Generator Exhaust

Waste Heat Recovery Chillers: How to Calculate ROI for Your Generator Exhaust

BROAD India Engineering Team
August 15, 2026
9 min read
Financial Analysis

Waste Heat Recovery Chillers: How to Calculate ROI for Your Generator Exhaust


Quick Links: The Opportunity | ROI Calculation | Real Examples | Get Analysis


Your generator is throwing money into the atmosphere.Exhaust gases at 400 - 550°C contain enough energy to power substantial cooling. Waste heat recovery chillers (Exhaust-Fired VAMs) capture this "free" energy. Here is the financial case for why capturing exhaust makes sense.

Understanding the Opportunity

A 1,000 kW generator produces ~1.5 MW of thermal exhaust energy.BROAD's exhaust-fired VAMs can convert this into 350-450 TR of cooling without burning a drop of extra fuel.


The ROI Calculation Framework

1. The Cost(CAPEX)

Exhaust - Fired VAM System(500 TR): ₹7.7 - 9.4 Crores

Comparable Electric Chiller: ₹5 - 5.9 Crores

Premium to Recover: ~₹3 Crores

2. The Savings(Annual OPEX)
  • Electricity Avoided: ₹1.89 Crores (2.1M kWh @ ₹9/unit)
  • Demand Charges Avoided: ₹43.2 Lakhs (900 kVA reduction)
  • VAM Operating Cost: -₹79 Lakhs (Auxiliaries/Maintenance)

Net Annual Savings: ₹1.53 Crores

3. The Payback

Formula: Premium CAPEX ÷ Net Annual Savings

Result: 1.95 Years(approx. 23 months)

* Includes 8 % generator efficiency gain from improved backpressure.

Real - World ROI Examples

  • Pharma(Bangalore): 600 TR VAM on 2x1250 kVA gensets. Payback: 2.1 Years.
  • Food Processing(Gujarat): 400 TR VAM on 1500 kVA genset. Payback: 1.8 Years.
  • Textile(Tirupur): 350 TR VAM on 1000 kVA genset. Payback: 1.6 Years.

Key Variables Affecting ROI

  • Operating Hours: 5,000+ hours/year yields ideal 2 - year payback.
  • Electricity Rates: Rates above ₹10/kWh accelerate payback to <18 months.
  • Carbon Credits: Can add ₹15-30 lakhs/year in value.

Lifecycle Value(20 Years)

While electric chillers cost ~₹38.8 Crores over 20 years(due to power costs), a Waste Heat Recovery Chiller costs only ~₹20.9 Crores total. Total Lifecycle Savings: ₹17.9 Crores.

Optimizing Your Investment

  • Right - Sizing: Match VAM capacity to actual generator load profiles.
  • Hybrid Setup: Use VAM for base load and electric chillers for peak tips.
  • Performance Guarantees: BROAD offers contractual COP guarantees tied to exhaust conditions.

⭐ Calculate Your Waste Heat Potential

Don't let free energy escape. Contact BROAD for a site-specific financial model.

Frequently Asked Questions

What is a Vapour Absorption Chiller?
It's a thermally-driven cooling system that uses water/LiBr solution and heat (from steam, hot water, exhaust, or gas) instead of electricity to produce chilled water, drastically reducing energy costs.
Can BROAD chillers run on waste heat?
Yes, our absorption chillers can capture waste heat from industrial processes, generator exhaust, or boiler steam to provide free cooling, resulting in significant OPEX savings.
Do you provide after-sales service in India?
Absolutely. BROAD India provides comprehensive design consultation, commissioning, operator training, and 24/7 after-sales support with remote monitoring capabilities.

Need Help With Your Cooling System?

BROAD India's engineering team can assess your facility's cooling requirements and recommend the most energy-efficient solution - from vapour absorption chillers to waste heat recovery systems.

Waste Heat Recovery Chillers: How to Calculat… | BROAD India