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Facilities with existing affected units subject to the area or major source Boiler NESHAP must conduct an energy assessment as part of the compliance requirements. The following are appropriate considerations to meet the energy assessment requirements.

What units require an energy assessment?

Develop a list of the boilers and process heaters at your facility that require an energy assessment. Energy assessments are required for:

  • Area Sources – existing coal, biomass or oil boilers with ratings ≥ 10 MMBTU/hr
  • Major Sources – all existing boilers and process heaters
Do you have a prior energy assessment or Energy Management System?

If you completed an energy assessment (EA) meeting the rule requirements on or after January 1, 2008 you may use that assessment to comply with the EA requirement. Also, if you have an Energy Management System that is compatible with ISO 50001 that includes the affected units, an EA is not required.

What is the required onsite duration for the facility’s energy assessment?

In order to determine the maximum onsite technical labor hours for the EA, you first must determine the annual heat input capacity for all affected units.  Document each affected boiler and process heater and the maximum heat input capacity for each unit.  Add the maximum hourly heat input capacity for all affected units and multiply by 8,760 hours per year to determine the total annual heat input capacity. The regulation provides the maximum onsite duration as follows:
NESHAP Energy chart 1

What is the scope of the energy assessment for your facility?

Based on the annual heat input capacity for all affected units, you can also determine which energy use systems should be reviewed as part of the onsite EA. Make a list of the energy use systems using energy (steam, hot water or electricity) associated with the affected boilers and process heaters. The percentage of energy used by those systems should also  be determined.

An energy use system uses energy (steam, hot water or electricity) provided by an affected boiler or process heater.  These systems may include process heating, compressed air, machine drive (motors, pumps, fans), process cooling, facility heating/ventilation/air conditioning, hot water, building envelope, lighting, or other systems using the energy from the affected units. Energy use systems may be segmented by production area or energy use area, such as product X manufacturing area, product Y drying area, building Z, etc.

Only energy use systems that utilize a portion of the energy produced from the affected units equal to or greater than the percentage shown in the table below must be evaluated.

NESHAP Energy Chart2

Who is qualified to conduct the energy assessment?

The regulation requires that a “Qualified Energy Assessor” conduct the energy assessment. The qualifications ensure that the assessor has demonstrated capabilities to evaluate energy savings opportunities for steam generation and major energy using systems and is familiar with boiler system operations (including combustion management, thermal energy recovery, insulation, steam trap and steam leak management, condensate recovery, and steam end-use management).  The assessor also must have capabilities and knowledge that includes familiarity with operating and maintenance practices for process heating systems, steam system improvement opportunities, process heating system opportunities, cogeneration systems, and industry-specific steam end use systems.

The Qualified Energy Assessor for your facility may be someone at your facility, a team of staff at your facility, a team including onsite and outside staff, or an outside consultant. 

What is the purpose of your energy assessment?

The assessment team will need direction on how thorough of an assessment is desired at your facility.  Does the organization want  an assessment that meets the requirements of the regulation and nothing more?  Or, is a more thorough review desired to identify additional energy savings measures beyond what is required in the regulation?

Do you want to utilize efficiency credits?

Under the major source boiler rule, there is an option for existing units at major sources to utilize efficiency credits for compliance demonstration in lieu of installing controls.  If your facility has preliminary data indicating that a unit is very close to an emission limit and would like an option for compliance other than installing controls, efficiency credits may be worth investigating. The major source regulation provides a method to calculate efficiency credits based on implementation of energy conservation measures identified in the energy assessment.  The energy assessment will include the establishment of a baseline or benchmark for future comparison with the energy savings gained from implementing energy conservation measures selected by the facility.  If your facility might benefit from efficiency credits, advance planning and coordination will be necessary to ensure compliance prior to the deadline.

What is the outcome of the energy assessment?

At the end of the assessment process, a report will be prepared identifying energy conservation measures and opportunities, and establishing costs and simple payback on investments, compared to potential energy savings.  Under the Boiler NESHAP, facilities are encouraged, but not required, to use the results of the EA to increase energy-efficiency and cost-efficiency of the boiler and process heater systems.

What to do next? 

The countdown has begun! Working through these considerations will help you to prepare a plan to meet the energy assessment deadlines, and procure any external assistance if required. Trinity Consultants has Qualified Energy Assessors and Certified Energy Auditors (CEA) available to assist you. For more information on how Trinity can assist with the energy assessment process, please contact  Jose Orsini at or Aimee Andrews at, or call your local Trinity office at 800-229-6655.NESHAP Energy Photo