Small, unobtrusive submeters
Brooklyn co-op installs small new meters that measure electrical usage and transmits information used to run the heating and safety systems. Some of the costs of the new meters are being paid for by NYSERDA. The benefits of submetering and the basics of how it works is explained.
Cadman Plaza North, a 27-story, 250-unit cooperative residential building near the Brooklyn end of the Brooklyn Bridge, is about to take a great leap forward into 21st Century energy management. The building is installing new electrical meters which will not only measure electrical usage but will also have the capacity to collect and transmit information useful in running the heating and safety systems.
These new meters, which will be owned and read by the cooperative, are small, unobtrusive, and easily installed without major rewiring. Perhaps the best part is that much of the cost of the installation will be paid for by the New York State Energy Research and Development Authority (NYSERDA), through its Comprehensive Energy Management (CEM) program.
At the completion of the installation phase of this submetering project, each apartment will have its own electric meter and be charged by the cooperative only for the actual electrical usage in that apartment. Until now, the building, built as a Mitchell Lama cooperative in the mid-1960s, has had a single electrical meter - a master-meter - for the whole structure. Under the master-meter set-up, the energy cost for the entire property is allocated to each apartment on a pro-ration formula based on unit size (or number of shares). High consumption appliances such as air conditioners and dishwashers have been subject to an additional flat fee surcharge collected by the cooperative.
There are many problems with master-metered buildings, not the least of which is the built-in inequity among shareholders. Studies show that in a master-metered property, 70 percent of the residents - low-users - consume only 50 percent of the energy; 20 percent of residents - medium-users - consume 25 percent of energy used, and 10 percent of residents - high-users - consume another 25 percent of the energy.
The high-users know that they have a good thing: their consumption is subsidized by their neighbors and they have no incentive to conserve. Even the surcharges for appliances don't discourage usage, as these are usually a flat fee per month. (For an extra cost of about $20 per month, a resident can run his air conditioner non-stop from May through September, using far more than is covered by the additional fee.)
"Our board is in favor of submetering because it will distribute the cost of electricity in a more equitable manner among the shareholders," notes Peter Burgess, president of Peter Burgess Management, the manager of Cadman Plaza North.
In addition to solving the inequity issue, submetering enables people to conserve energy and rewards them for their efforts. Even though a master-metered property enjoys the benefits of wholesale rates (as does a submetered building), there is no way for the co-op to manage its consumption effectively. Master-metered buildings that try to control their energy costs often end up resorting to intrusive policies, such as apartment inspections to see if tenants have non-complying appliances installed. Resentment towards the board and management is a frequent result.
"Submetering makes a lot of sense for a building like Cadman Plaza North," says Herbert E. Hirschfeld, a professional engineer with several decades of experience in finding metering solutions for real estate owners and the technical consultant for the Cadman Plaza North project. "The building will be able to buy electricity at wholesale rates and the shareholders who choose to conserve energy will have the information they need to plan and manage their energy usage."
The actual mechanics of converting a master-metered building to submeters used to be quite expensive, which tended to discourage implementation. In most cases, each apartment had its own fuse box or circuit-breaker panel and the meter needed to be directly wired into that box. In addition to the installation cost, the property had the ongoing expense of sending someone to read the meters each month.
Engineers have developed technical innovations to address those issues. Power Line Communications (PLC) technology entails installing a meter in each apartment that measures usage and communicates the information to a central computer over the existing building wiring. This saves the cost of expensive building rewiring. In addition to PLC, wireless communication has been incorporated into some newer metering systems. With a wireless set-up, each meter sends the information it collects to the main computer via a radio signal. These technologies have helped to make submetering a viable solution for buildings coming off master-metering.
(Submetering is also different from direct metering. In a direct-metered building, each apartment has its own meter that is owned and read by the utility supplier. Apartment owners are billed directly by the utility and the building is not involved. Direct-metered shareholders pay retail rates and don't get the benefits of wholesale pricing offered by submetering. There are programs available for buildings to convert from direct to submetering.)
In Cadman Plaza North, the board will be installing a compact meter about the size of two cigarette packs. It uses wireless communication technology and is manufactured by Intech 21, a Long Island-based company. The new meter will not only measure and report electrical usage, but also record the time of day when the electricity is being used. In a deregulated energy market, price differences based on the time of consumption can be significant. Thus, a "smart" meter system will enable the apartment residents to purchase energy efficiently (for example, running a dishwasher in the evening when rates are lower) and realize the cost savings associated with "real time" pricing.
The meter being installed in Cadman Plaza North also has a temperature sensor that enables the system to collect temperature readings from every apartment and discern the heating pattern in the building. This information can then be used to control and manage the building's. The system should then be able to distribute heat to where it is needed and not overheat other areas.
Boiler optimization is only one of the potential additional benefits that can be provided by the new high-tech meters. Stevenson Commons, a multi-building complex in the Bronx, is a demonstration site for NYSERDA's Integrated Building Control Module program. This project includes submetering, apartment temperature monitoring for boiler optimization. and monitoring of safety and security systems.
"With this system, which is web-enabled and connected to the internet, you can monitor and control most of the major building systems from anywhere in the world," says Hirschfeld. "You can go online and tell if the access doors to the roof are closed without having to send personnel to check."
In the apartments at Cadman Plaza North, the connection to the box is made by drilling a small hole in the sheetrock and connecting sensor wires into the back of the box. "It will take a technician only about an hour to complete each apartment installation," Hirschfeld says. Because of the building's participation in the NYSERDA program, the net cost will be about $150 per unit.
"That's about one-third of the actual cost," says Hirschfeld. "That's a pretty good deal for all the additional capability that is being installed, and on top of that they are equipped to take advantage of future NYSERDA savings programs when they are introduced."