At a Glance


Government/Public Administration

Project Type

Commercial Energy Efficiency




New York, NY


Nirmalya Chanda created standardized calculators to estimate savings from energy conservation measures and identified the most suitable buildings for implementing these projects.


NYC Department of Citywide Administrative Services (DCAS) Division of Energy Management (DEM) enlisted EDF Climate Corps fellow Nirmalya Chanda to improve the Accelerated Conservation and Efficiency (ACE) program application process. The energy savings calculations, a critical aspect of the application, needed to be standardized to ensure uniform and accurate estimates of savings from conservations measures. The agency was also interested in identifying target buildings and analyzing the best energy conservation measures (ECM) for each of the identified buildings.


Nirmalya developed standardized Excel-based energy savings calculation models for 12 ECMs. The models included switching fuels, upgrading the lighting and replacing, boilers, inefficient windows with high performance alternatives, chillers in air conditioning systems, damaged insulations of pipes used for heating and cooling purposes, and faulty steam traps. Calculations were also included for installing COGEN systems, BMS, roof top units, variable frequency drives, and energy efficient elevators. These 12 standardized calculators covered the most commonly seen ECMs under the ACE program—such as such as pipe insulation and steam trap replacement—as well as the more advanced-- installing COGEN systems and roof top units for HVAC systems.

Nirmalya also analyzed 2013, 2014 and 2015 building energy data of 2702 buildings and used the tools available at DCAS to analyze the potential energy savings of 21 ECMs. He devised a ranking system for the ECMs, which determined the best for every building. Using a target building identification system tool that he developed, Nirmalya identified 1153 buildings for implementing energy conservation solutions. 

Potential Impact

The Excel based energy savings calculators can be used by agencies to standardize calculation methodologies when applying for funding under the ACE program—starting with the next round of ACE applications-- and to estimate energy savings for projects under the ExCEL program, provided that they are validated by DCAS. 

Using the target building identification system, DCAS can better advise agencies on which buildings to target for potential ECM, and agencies seeking ACE funding can use this information to get an estimate of the energy savings from individual ECMs without engaging in detailed calculation. Overall, more projects will be generated under the ACE program, bringing the City closer to reaching its 80X50 goal.

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