The benefits of regulatory boiler energy assessments
They provide real opportunities for facilities to assess energy-saving options
The large energy demand of boilers in manufacturing and industrial facilities creates opportunity to increase efficiency, reduce fuel use, lower operating costs and allow facilities to reduce emissions.
One-time boiler energy assessments are now required at approximately 80 facilities in New Hampshire by the U.S. Environmental Protection Agency’s MACT (Maximum Achievable Control Technology) and GACT (Generally Available Control Technology) rules. Sources of hazardous air pollutant, or HAP, emissions must complete boiler energy assessments by March 21, 2014, or Jan. 31, 2016, depending on the level of HAP emissions from the facility and boiler capacity.
Don’t consider the required boiler energy assessments an unnecessary, but obligatory, expense. Boiler energy assessments provide real opportunities for large facilities to assess energy-saving options such as fuel switching, thermal energy recovery, insulation upgrades, and steam end-use.
Facility decision-makers have a choice of whether the energy assessment is performed internally or by an external resource. A facility could benefit from an external third party auditor performing the energy assessment because the third party provides objective understanding of energy conservation measures and brings the knowledge of efficiency improvements that have been applied at similar facilities successfully. Alternatively, you may have the ability to conserve funds dedicated to regulatory compliance by using a team approach to facilitate the energy assessments.
Improving efficiency of boilers may also save financial resources by:
• Reducing fuel demand through improved boiler efficiency and thermal-energy recovery
• Reducing fuel costs by switching to more economical fuel types if fuel switching proves favorable based on payback analysis
• Lowering actual air emissions, thereby reducing annual emissions fees paid to state regulatory agencies.
For example, a facility that has a single 10 MMBtu/hr boiler that operates for approximately 4,000 annual full load hours is likely to be required to perform an energy assessment per the boiler GACT rule.
As summarized in the accompanying chart, prior to the assessment being performed, the thermal efficiency of the boiler may be 83 percent. Basic recommendations resulting from the energy assessment could include more frequent cleanings, adding a condensing economizer, a combustion air pre-heater, blowdown waste heat recovery, and/or oxygen trim controls.
By implementing these procedures and technologies, the boiler’s thermal efficiency could be increased to 91 percent, thereby decreasing annual fuel use and cost (savings of approximately $72,000 per year) and decreasing greenhouse gas emissions by more than 250 megagrams of CO2 per year.
An additional higher level recommendation that could be considered includes an upgrade to a highly efficient natural gas burner. The fuel switch for a boiler of this size would result in an annual fuel cost savings of more than $400,000. The fuel switch also has the potential to decrease greenhouse gas emissions by more than 700 megagrams of CO2 per year.
For those facilities required to perform boiler energy assessments, this example demonstrates the reduction in emissions and potential value of improved efficiency that can result from high level recommendations of the energy assessor. Regulatory boiler energy assessments are far from just an obligatory expense.
Heather Little is a senior project manager with Concord-based Sanborn, Head & Associates.