Emissions Control

The patented ultra-clean emissions control technology has been rigorously tested by independent labs and shown to consistently reduce the emission of criteria pollutants contributing to smog (CO and NOx) to near zero levels for natural gas engines.

Conforming to the current carbon monoxide and nitrogen oxide standards

Our emissions technology, developed with funding from the California Energy Commission and Southern California Gas Company, has been independently verified by New Jersey’s Department of Environmental Protection and by AVL California Technology Center. Emissions measurements from stationary systems equipped with the ultra-low emissions technology conform to the current California Air Resource Board (CARB) 2007 carbon monoxide (CO) and nitrogen oxide (NOx) standards for distributed power generation.

Engines retrofitted with our Ultera technology measure at or below current natural gas powered fuel cell emissions levels.

Understanding the Ultera Emissions System

History of Our Technology

Our journey in the emissions after treatment business began in 2006 as a response to California’s South Coast Air Quality Management District’s (SCAQMD) implementing more aggressive emissions rules based on California Air Resources Board (CARB) standards.

September 2016

Auto emissions control company Ultra Emissions Technologies Ltd. valued at $58.2M in third round funding

October 2016

Tecogen to develop Ultera emissions technology for propane powered fork truck market in collaboration with select industry manufacturers and with research funding from PERC

June 2016

Ultra Emissions Technologies Ltd. Phase 1 testing proves Ultera highly effective at automotive emissions control, delivering a substantial reduction of pollutants in excess of currently available technologies

April 2016

Phase 1 Ultera testing at AVL California Technology Center begins on light duty vehicle

January 2016

Ultra Emissions Technologies Ltd. contracts AVL for Phase 1 third party testing and validation of Ultera system for a gasoline vehicle platform

December 2015

Ultra Emissions Technologies Ltd. joint venture formed on advice from Emissions Advisory Committee to develop Ultera for automotive applications

November 2015

Emissions control technology rebranded as Ultera® (formerly “Ultra”)

October 2015

First biofuel application of an Ultera ultra-clean emission retrofit kit

Phase 2 order for additional standby generator emissions control retrofit kits received

Emissions Advisory Committee formed to explore application of Ultera system to gasoline fueled vehicle market following reports of widespread auto emissions problems

February 2015

Application of Ultera retrofit to commercial 130kW standby natural gas generator

November 2013

Worldwide patent granted for Tecogen’s Ultera low emissions technology

January 2012

Ultera made available on entire line of Tecogen’s clean energy equipment


Fourth-generation emissions controls capable of meeting latest ultra-low California standards, with partial R&D sponsorship coming from CEC, Sempra Utilities and others


Patent granted for controlling engine emissions


First low-emissions units developed for Southern California

End Market Applications

Our Ultera-low emissions retrofit kits have been successfully installed on the following engines:

general electric