Electrical Submetering and Time Sensitive Pricing

Noble Mansion is a master metered, rental type, residential building located at 1500 Noble Avenue, near the intersection of the Cross Bronx Expressway and the Bronx River Parkway in the Bronx. All 237 apartments are occupied by rent stabilized tenants and under the jurisdiction of DHCR and subject to DHCR guidelines. Noble Mansion implemented Time Sensitive Pricing (TSP) immediately upon completion of its submetering installation during 2007 and initiation of billing residents for electricity, thereby eliminating the confusion and negative feedback from tenants and building management which may occur when the billing process is altered from conventional to TSP billing.

Equipment – A wireless submetering system with integral temperature sensor

An apartment submeter was installed inside each apartment adjacent to the breaker panel in order to take advantage of an integral temperature sensor. The temperature sensor provides management the ability to monitor apartment temperatures and to optimize the building heating distribution system and boiler operation. This feature has assisted in addressing resident heat complaints and should result in significant fuel savings which will further improve the energy efficiency of this building.

Billing History
Noble Mansion Before Submetering
Baseline year before submetering

Noble Mansion After Submetering
Most recent year after submetering

An analysis of the building electrical data was conducted by Herbert E. Hirschfeld, P.E. in order to determine the impact of electrical submetering combined with time sensitive pricing on the building’s electrical usage (kWh), demand (KW) and associated utility costs. In order to determine the building’s cost benefit (or cost avoidance) due to submetering as well as TSP, the base line year (established prior to submetering – see Fig #1) was adjusted based on electric utility costs and weather data (cooling degree days or CDD) which occurred during a recent year of comparison after submetering (4/5/07 – 4/4/08 – see Fig #2). Time Sensitive Pricing was implemented immediately in order to eliminate the confusion inherent in changing billing methods for the residents. In this example the difference between the adjusted baseline period and the current period yielded an adjusted reduction in usage of 326,730 kWh or 18.9% and a cost avoidance of $65,314 which represents 19.18% of the adjusted building electric costs. Additionally, there was a reduction in peak demand of approximately 12.26% which should have resulted in Noble Mansion obtaining additional incentives by participating in the NYS ISO ICAP program.

Resultant Adjusted Reduction in Usage of 326,730 kWh or 18.9% and a Cost Avoidance from Electrical Submetering of $65,314 or 19.18%, as well as a Reduction in Billing Demand of 12.26%
Submeter Online

Contributed by Herbert E. Hirschfeld, P. E.