Built in the 1970’s, Coppergate House is a 150-unit apartment building, located in central New Jersey, where energy costs have nearly doubled over the last few years. Those rising energy costs took an increasing bite out of Coppergate’s annual operating budget.

Coppergate’s winter heating and year-round domestic hot water was produced from an aging boiler system. Due to its age, the boiler had lost substantial efficiency and its maintenance costs had risen considerably. This combination along with the rising energy costs was creating an ever-increasing cost spiral.

Since Coppergate is home to seniors and owned by a private, nonprofit organization, rising costs of any kind have a significant impact. “I was seeking an effective strategy to both lower my energy costs and replace my older boiler system,” said Ray Marzulli, property manager of Coppergate House.


Working with Coppergate, American DG Energy, Waltham, Mass., conducted an energy audit to determine the feasibility of a cogeneration application. The audit involved evaluating the historical energy use patterns, assessing the installation and system modification costs, and estimating annual savings.

From the audit, American DG Energy determined that providing the facility with its On-Site Utility cogeneration system would enable Coppergate to realize significant energy cost savings at no cost and without the burden of maintaining the equipment. The On-Site Utility offers customers the energy saving benefits of cogeneration - producing electricity, hot water, and heating - through a long-term guaranteed-savings contract, without any capital costs or operating responsibilities. American DG owns and operates the equipment. Coppergate management agreed to go forward with the project. “We have significant experience with cogeneration. Once we had evaluated our options, selecting an On-Site Utility was an easy decision to make,” stated Marzulli.

American DG Energy installed a CM75 cogeneration module on the premises at Coppergate. As part of that installation, it was necessary to also make significant piping and control changes to the heating and domestic hot water architecture.

The single most important modification made was to eliminate non-heating season use, specifically the production of domestic hot water, of the older and more inefficient boilers. Instead of generating hot water using a boiler, whose efficiency had been de-rated to significantly below 65 percent, the CM75 module utilizes its thermal output to generate domestic hot water at a significant level of savings.

Another alteration, essential to ensure maximum efficiency and cost savings, involved adding new meters and controls that work in a coordinated way to reduce the energy formerly demanded by the older, less efficient boiler system. The old boiler system now acts as the backup instead of the primary heating system for Coppergate.

The new system’s value is not limited to the boiler solution. The CM75 module has delivered significant savings on electricity. It helps Coppergate keep summer peak electrical costs in check by providing a guaranteed method of producing electricity, cheaper than what management would otherwise pay to the local utility.

The project has been very successful. Coppergate now has an efficient, reliable energy source for all its electricity, heat, and domestic hot water needs. At the same time, the facility has also realized significant energy cost savings. Marzulli explained, “With American DG Energy’s On-Site Utility, we’re saving 15 percent on our electricity costs. It adds up to thousands of dollars in savings annually.”

Project Highlights:

American DG Energy achieved the following goals at Coppergate House:

• Installed a CM75 cogeneration module.

• Modified piping and controls for the heating and domestic hot water architecture.

• Eliminated use of the old boilers during the non-heating season.

• Utilized CM75 module thermal output to generate domestic hot water.

• Installed additional metering.

• Reduced year-round demand on the old boiler system.

For more information, visit the American DG Energy Website at www.americandg.com.

Publication date:12/25/2006