# Combined heat and power: What to track

Watch hours, spark spread, NOx and the greening grid

Source page: https://www.materialinsights.org/energy/e_chp/tracking/

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 examples^[4](https://iac.university/file/general/CHP%20TAP%20Training%20for%20IACs%20-%20February%2011%202021.pdf) | → 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 0.70-1.42^[1](https://betterbuildingssolutioncenter.energy.gov/sites/default/files/attachments/CHP_Reciprocating_Engines.pdf)^[2](https://www.energy.gov/sites/default/files/2017/06/f35/CHP-Absorption%20Chiller-compliant.pdf) | → 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 MW^[4](https://iac.university/file/general/CHP%20TAP%20Training%20for%20IACs%20-%20February%2011%202021.pdf) | → 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)^[1](https://betterbuildingssolutioncenter.energy.gov/sites/default/files/attachments/CHP_Reciprocating_Engines.pdf)^[3](https://19january2025snapshot.epa.gov/chp/chp-benefits) | ↘ 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 fuels^[1](https://betterbuildingssolutioncenter.energy.gov/sites/default/files/attachments/CHP_Reciprocating_Engines.pdf) | → 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.^[7](https://taxation-customs.ec.europa.eu/carbon-border-adjustment-mechanism/cbam-definitive-regime_en)^[10](https://www.cemnet.com/News/story/182273/eua-trading-in-very-narrow-range-awaiting-news-from-ets-revision-moves-driven-by-gas-price.html)^[11](https://taxation-customs.ec.europa.eu/carbon-border-adjustment-mechanism/price-cbam-certificates_en)^[12](https://icapcarbonaction.com/en/news/compliance-obligations-under-indias-carbon-credit-trading-scheme-enter-force-seven-sectors)^[13](https://climateriskhorizons.com/app/uploads/2026/07/CCTS-Report_WebsiteDraft_28.07.26-1.pdf) | ↕ 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](https://iac.university/file/general/CHP%20TAP%20Training%20for%20IACs%20-%20February%2011%202021.pdf) | ↕ 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](https://betterbuildingssolutioncenter.energy.gov/sites/default/files/attachments/CHP_Reciprocating_Engines.pdf) | → 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](https://www.meti.go.jp/shingikai/energy_environment/dr_ready/pdf/007_06_00.pdf) | ↗ improving | Shows micro-CHP can scale with subsidies; unit cost is still high. |

#### Sources

1. [Reciprocating Engines, CHP Technology Fact Sheet Series (DOE/EE-2764)](https://betterbuildingssolutioncenter.energy.gov/sites/default/files/attachments/CHP_Reciprocating_Engines.pdf) US Department of Energy, 2023
2. [Absorption Chillers for CHP Systems, CHP Technology Fact Sheet Series (DOE/EE-1608)](https://www.energy.gov/sites/default/files/2017/06/f35/CHP-Absorption%20Chiller-compliant.pdf) US Department of Energy, 2017
3. [CHP benefits (archived page, snapshot of 19 January 2025)](https://19january2025snapshot.epa.gov/chp/chp-benefits) US EPA Combined Heat and Power Partnership, 2025
4. [CHP TAP training for Industrial Assessment Centers](https://iac.university/file/general/CHP%20TAP%20Training%20for%20IACs%20-%20February%2011%202021.pdf) US DOE CHP Technical Assistance Partnerships, 2021
5. [CBAM definitive regime](https://taxation-customs.ec.europa.eu/carbon-border-adjustment-mechanism/cbam-definitive-regime_en) European Commission, Taxation and Customs Union, 2026
6. [Home fuel cell ENE-FARM and demand response (Fuel Cell Commercialization Conference of Japan, DR-ready study group, 25 November 2025)](https://www.meti.go.jp/shingikai/energy_environment/dr_ready/pdf/007_06_00.pdf) Ministry of Economy, Trade and Industry (METI) committee papers, 2025
7. [EUA trading in very narrow range awaiting news from ETS revision; moves driven by gas price](https://www.cemnet.com/News/story/182273/eua-trading-in-very-narrow-range-awaiting-news-from-ets-revision-moves-driven-by-gas-price.html) CemNet (International Cement Review), 2026
8. [Price of CBAM certificates](https://taxation-customs.ec.europa.eu/carbon-border-adjustment-mechanism/price-cbam-certificates_en) European Commission, Taxation and Customs Union, 2026
9. [Compliance obligations under India's Carbon Credit Trading Scheme enter into force for seven sectors](https://icapcarbonaction.com/en/news/compliance-obligations-under-indias-carbon-credit-trading-scheme-enter-force-seven-sectors) International Carbon Action Partnership (ICAP), 2026
10. [Unlocking Ambition for India's Carbon Credit Trading Scheme (Anirudh TR)](https://climateriskhorizons.com/app/uploads/2026/07/CCTS-Report_WebsiteDraft_28.07.26-1.pdf) Climate Risk Horizons and Energy Transition Ventures, 2026

## Other sections

- [Summary](https://www.materialinsights.org/energy/e_chp/index.md)
- [Overview](https://www.materialinsights.org/energy/e_chp/overview/index.md)
- [Correlation](https://www.materialinsights.org/energy/e_chp/correlation/index.md)
- [Science and thermodynamics](https://www.materialinsights.org/energy/e_chp/rc-sci/index.md)
- [Engineering and integration](https://www.materialinsights.org/energy/e_chp/rc-eng/index.md)
- [Economics and contracts](https://www.materialinsights.org/energy/e_chp/rc-econ/index.md)
- [Impact and additionality](https://www.materialinsights.org/energy/e_chp/rc-impact/index.md)
- [Relationships](https://www.materialinsights.org/energy/e_chp/links/index.md)