Waste-heat power (steam Rankine): Economics and contracts

Free heat makes power cheaper than the grid, mostly

With free heat and long running hours, steam WHR makes power at roughly USD 20-60 per MWh, well below typical industrial tariffs, so paybacks of a few years are common. The risks sit with the host plant.

Levelised cost of heat or avoided cost

DOE puts installed steam Rankine cost at USD 1,200-3,000 per kW (cheaper per kW at larger sizes) and operating cost at 0.5-1.3 US cents per kWh. Assuming 7,000 hours a year, an 8% cost of capital and 20 years, that gives roughly USD 23-57 per MWh (calculated). Against power bought at USD 0.10 per kWh, simple payback is about 2-5 years (calculated). For scale, a DOE CHP training example priced bought-in power at USD 0.1328 per kWh. Because the fuel is already paid for by the host, the only variable cost is operation and maintenance. For Indian cement plants CSE reports paybacks of 55-60 months (about 4.6-5 years), and Triveni cited operating cost falling from about Rs 4 per unit for thermal power to about Rs 0.5 per unit with WHR (company view).^1111516

Host factory credit risk

The unit is worthless without the kiln, furnace or engine that feeds it, so an investor is really lending against the host. Large integrated cement producers are relatively strong hosts: UltraTech alone runs 444 MW of WHR. Risks are kiln closure, a switch to a new line elsewhere on the site, lower clinker output in a downturn, and process changes (for example more preheater stages or alternative fuels) that cut exhaust heat. Indian cement WHR is mostly owned by the cement company for captive use, which keeps the credit question inside one balance sheet. Even gas pipeline hosts change: Ormat reports that its recovered-energy units run below capacity because the compressor stations feeding them run less, and that one customer is expected to end its waste heat agreement (2025 annual report).⁴²²

Heat-as-a-service and ESCO models

Third-party ownership is less common for steam WHR than for CHP, because the boiler sits inside the host's process. The clearest model comes from gas pipelines: Ormat holds the rights to compressor-station turbine exhaust heat, owns the recovery units and sells the power to utilities. A 2008 release (dated) described nine units of nearly 50 MW on the Northern Border pipeline and a 20-year PPA with Great River Energy; the 2025 annual report still lists about 50 MW across three recovered-energy portfolios. Those plants use an organic cycle, but the heat-rights-plus-PPA structure transfers to steam WHR. A build-own-operate deal shifts technical risk to the developer but needs take-or-pay or minimum-heat clauses that the host must accept.¹²²²

Sources

1. Waste Heat to Power, CHP Technology Fact Sheet Series (DOE/EE-2347) US Department of Energy, 2021
2. UltraTech becomes first Indian company with 2 GW green power capacity Construction World, 2026
3. CHP TAP training for Industrial Assessment Centers US DOE CHP Technical Assistance Partnerships, 2021
4. Ormat Technologies signs a new power purchase agreement with Great River Energy (dated) Ormat Technologies (press release), 2008
5. Cementing the Transition: the role of energy efficiency in decarbonising India's cement sector Centre for Science and Environment, 2026
6. Demand for WHRS has slowly picked up across the country, says Arun Mote, Triveni Turbines (interview; company view) EPC World, 2021
7. Annual Report 2025 including Form 10-K (OREG recovered energy plants, table of power plants and footnote 8) Ormat Technologies (SEC filing), 2026