Combined heat and power: What to track
Watch hours, spark spread, NOx and the greening grid
What this tab covers The attributes worth tracking regularly, with the latest value, the direction of travel and why each matters.Track hours, efficiency, host health, abatement per dollar against a changing grid, heat exchanger fouling and carbon rules, plus spark spread and NOx limits.
| Category | Attribute | Latest | Trend | Why it matters |
|---|---|---|---|---|
| Operational | Capacity factor and operating hours | 7,450-8,700 h/yr in DOE examples4 | → stable | Fewer hours mean fewer kWh to repay fixed capex, so payback lengthens quickly. |
| Techno-economic | Thermal efficiency or COP over time | 75-82% overall (engines); chiller COP 0.70-1.4212 | → stable | Falls if heat is dumped because demand drops. |
| Counterparty | Host counterparty credit and utilisation rate | Third-party BOO deals such as Solvay/DTE 8 MW4 | → stable | Minimum-take clauses tie returns to host survival. |
| Impact | t CO2e avoided per dollar invested | About 1.0-2.1 t CO2 per USD 1,000 of capex per year for a 1 MW engine (calculated)13 | ↘ worsening | Uses EPA's 4,100 t/yr saving and DOE capex; the saving falls as grids decarbonise. |
| Operational | Heat exchanger fouling and cleaning frequency | Low on natural gas; higher on biogas and liquid fuels1 | → stable | Exhaust boiler and jacket exchanger fouling cut heat output first. |
| Policy | Local carbon pricing and penalties | EU ETS December 2026 allowance about EUR 84.50/t (23 October 2026), after trading at EUR 82-87 over the previous month; CBAM certificate price EUR 82.32/t for Q3 2026, up from EUR 75.28 in Q2 (definitive regime since 1 January 2026). India CCTS: intensity targets bind about 490 entities in seven sectors for 2025-26 and 2026-27 against a 2023-24 baseline; no certificate trading had been reported by July 2026, and analysts assume an opening price near USD 10/t CO2e.710111213 | ↕ volatile | Carbon prices raise the cost of gas burned on site as well as grid power. EU prices sit in the low to mid EUR 80s while ETS reform is debated; India's targets are modest (cement average cuts of about 1.89% by 2025-26 and 3.22% by 2026-27), so CCTS adds little value to recovery projects for now. |
| Market | Spark spread | DOE example: 4.2 US cents/kWh to generate vs about 8 cents/kWh bought (calculated)4 | ↕ volatile | Gas and power price swings decide CHP economics. |
| Compliance | NOx limits | Lean-burn 0.5-1.0 g/bhp-hr before SCR; SCR removes 90-95%1 | → stable | Tighter urban air rules add capex and O&M. |
| Market | Residential micro-CHP deployment | ENE-FARM: about 550,000 units sold in Japan since 2009 (industry paper to METI, November 2025)9 | ↗ improving | Shows micro-CHP can scale with subsidies; unit cost is still high. |
Sources
- Reciprocating Engines, CHP Technology Fact Sheet Series (DOE/EE-2764) US Department of Energy, 2023
- Absorption Chillers for CHP Systems, CHP Technology Fact Sheet Series (DOE/EE-1608) US Department of Energy, 2017
- CHP benefits (archived page, snapshot of 19 January 2025) US EPA Combined Heat and Power Partnership, 2025
- CHP TAP training for Industrial Assessment Centers US DOE CHP Technical Assistance Partnerships, 2021
- CBAM definitive regime European Commission, Taxation and Customs Union, 2026
- Home fuel cell ENE-FARM and demand response (Fuel Cell Commercialization Conference of Japan, DR-ready study group, 25 November 2025) Ministry of Economy, Trade and Industry (METI) committee papers, 2025
- EUA trading in very narrow range awaiting news from ETS revision; moves driven by gas price CemNet (International Cement Review), 2026
- Price of CBAM certificates European Commission, Taxation and Customs Union, 2026
- Compliance obligations under India's Carbon Credit Trading Scheme enter into force for seven sectors International Carbon Action Partnership (ICAP), 2026
- Unlocking Ambition for India's Carbon Credit Trading Scheme (Anirudh TR) Climate Risk Horizons and Energy Transition Ventures, 2026