Power for data centers, clean air for communities

The emissions a data center must monitor depend on its onsite power generation equipment, operating hours, fuel type, and local regulatory requirements. Facilities with diesel or natural gas generators typically monitor pollutants such as:

• Nitrogen oxides (NOx)
• Carbon monoxide (CO)
• Oxygen (O₂) for combustion efficiency and emissions correction
• Sulfur dioxide (SO₂), depending on fuel type
• Particulate matter (PM), where required
• Greenhouse gases (GHGs), if subject to reporting programs

Monitoring requirements vary by jurisdiction and permit conditions, so facilities should review applicable federal, state, and local regulations.

Data center generators are subject to emissions regulations during testing and operation, and accurate monitoring supports regulatory compliance, ESG reporting, and environmental accountability.

A CEMS continuously measures pollutant concentrations in exhaust gases to support regulatory compliance, emissions reporting, and operational oversight.

Stack testing and Continuous Emissions Monitoring Systems (CEMS) serve different but complementary purposes.

Stack testing is a periodic measurement performed by certified testing organizations to verify emissions during specific operating conditions. It provides a snapshot of emissions performance and is commonly used for permit compliance, equipment certification, and emissions validation.

CEMS continuously measures pollutant concentrations in the exhaust stream while equipment is operating. Instead of periodic snapshots, CEMS provides ongoing data that can demonstrate continuous compliance, identify operational issues quickly, and support regulatory reporting.

Many facilities use both approaches, with stack testing used to validate performance and CEMS providing continuous operational monitoring.

Continuous Emissions Monitoring is required when specified by environmental regulations or operating permits. Requirements vary depending on factors such as:

• Generator size and capacity
• Fuel type
• Annual operating hours
• Facility emissions
• Air permit conditions
• Federal, state, or local regulations

In the United States, facilities subject to EPA regulations such as certain New Source Performance Standards (NSPS), National Emission Standards for Hazardous Air Pollutants (NESHAP), Title V permits, or state permitting programs may be required to install and operate CEMS. Facilities should consult their permit requirements to determine whether continuous monitoring is mandatory.

Continuous monitoring is typically required for larger combustion sources or where environmental permits mandate continuous emissions reporting. Smaller backup generators often rely on periodic stack testing.

Accurate emissions monitoring helps facilities demonstrate regulatory compliance, improve combustion efficiency, support sustainability reporting, reduce compliance risk, and maintain operational reliability.

Successful long-term compliance requires more than installing monitoring equipment. Organizations can strengthen their compliance programs by:

• Selecting monitoring systems that meet applicable regulatory performance specifications
• Establishing routine calibration and preventive maintenance schedules
• Performing regular quality assurance and quality control (QA/QC) checks
• Maintaining accurate emissions records and documentation
• Training personnel on system operation and regulatory requirements
• Working with experienced service providers to keep systems operating reliably

A proactive compliance strategy helps reduce downtime, improve data quality, and simplify regulatory reporting.

U.S. EPA regulations and performance specifications have historically been developed around reference measurement technologies. For NOx and CO monitoring, chemiluminescence analyzers for NOx and non-dispersive infrared (NDIR) analyzers for CO are well-established technologies with decades of demonstrated performance.

These analyzer technologies are widely accepted because they:

• Meet EPA reference and performance specifications for many applications
• Provide high measurement accuracy and sensitivity
• Have extensive validation across a broad range of combustion sources
• Are supported by well-defined quality assurance procedures

Thermo Fisher offers CEMS, iQ Series gas analyzers (42iQ, 48iQ, 410iQ), and the MAX-iR FTIR Gas Analyzer for emissions monitoring and compliance in power generation and data centers.

A relative accuracy test audit (RATA) verifies CEMS accuracy by comparing its measurements to approved reference methods.

The MAX-iR FTIR gas analyzer provides simultaneous, high-accuracy multi-gas measurements, making it well suited for reference data collection during RATA testing.

Yes. Thermo Fisher gas analyzers integrate with plant control systems, supervisory control and data acquisition (SCADA) platforms, and data acquisition systems for streamlined monitoring and reporting.

Accurate emissions data supports Scope 1 emissions reporting, regulatory transparency, and long-term sustainability goals.

Yes. Thermo Fisher Scientific’s gas analyzers support natural gas and hydrogen-blend combustion, enabling compliance as power systems evolve.

They are commonly installed at power plants, gas turbines, CHP systems, generator stacks, and data center power facilities.

Yes. Requirements vary by country and local authority; customers should consult their local Thermo Fisher representative for guidance.

Many utilities standardize on a single analyzer platform to improve consistency, simplify maintenance, and reduce operating costs across multiple facilities.

Standardization can provide several advantages:

• Common spare parts inventory
• Consistent operating procedures
• Simplified technician training
• Faster troubleshooting and maintenance
• Uniform calibration and quality assurance practices
• Easier integration with plant control and data acquisition systems

Using a standardized analyzer platform can also reduce lifecycle costs and help maintain consistent measurement quality across an organization's fleet.

The long-term value of an emissions monitoring system depends not only on the analyzer itself but also on the expertise behind it. Strong technical support and training can help organizations:

• Install and commission systems correctly
• Maintain analyzer performance over time
• Minimize downtime through faster troubleshooting
• Stay current with regulatory and quality assurance requirements
• Train new personnel on operation and maintenance
• Extend equipment life and reduce total cost of ownership

When evaluating analyzer suppliers, organizations should consider the availability of factory-trained service personnel, application expertise, training programs, spare parts availability, and long-term service support in addition to the analyzer's technical specifications.