This summer, NorthBay Healthcare took a giant step toward greener facilities when it flipped the switch on cogeneration systems at VacaValley Hospital and NorthBay Medical Center.

The move is expected to save millions in energy costs during the next 10 years, according to Dave Mathews, director of plant operations and general services for NorthBay.

The units—two at NorthBay and one at VacaValley—were installed by Siemens Building Technologies Inc., Energy and Environmental Solutions group, based in Hayward. A 10-year energy savings performance contract and three-year maintenance plan with Siemens guarantees savings of nearly 30 percent in annual electricity costs.

The new system will reduce the need for utility-delivered energy and save the hospitals money by producing both heat and electricity.

‘We are under tremendous pressure to find new ways to manage operating costs without impacting patient care or staffing,’ said Mathews.

Facility-wide energy efficiency improvements installed during the past three years have been designed to reduce electrical, heating, cooling and waste disposal costs, as well as allow NorthBay Healthcare to generate some of its own electricity.

“However, it’s the cogeneration system that will offer the biggest portion of energy savings, contributing nearly 30 percent of total annual kilowatt-hour reductions at both facilities,” said Scott Wallace of Siemens Building Technologies.

The units use small, extremely efficient natural-gas engines—similar to helicopter engines—to spin the generators that make electricity.

When operating, these engines create tremendous amounts of heat, which in theory could be wasted if just allowed to vent. With cogen, the heat generated by the engines is captured through heat exchangers to heat the water that would normally have to be heated separately by boilers—much like a hot water heater in one’s home. This process offsets the natural gas normally used to heat the water used to regulate Heating Ventilation and Air Conditioning (HVAC) systems.

The new-found energy efficiency will contribute to the overall sustainability of NorthBay’s facilities. Energy savings for both facilities are guaranteed to reach 2,765,634 kwh per year. According to Siemens, during the 10-year term of the contract, this will reduce emissions of typical greenhouse gases by approximately 17 million pounds and save emissions equivalent to driving the typical family car some 100,000 miles. Siemens also financed the project, loaning NorthBay the money to complete it.

“Implementing this performance contract solution with Siemens was an excellent way to achieve our cost-savings goals because the energy-efficiency upgrades—which normally would consume our capital improvement budgets—are financed by the savings the upgrades are guaranteed to produce. More importantly, we will have better overall control of each facility’s environment, which means better patient and staff comfort, as well as a significant reduction in environmental emissions,” said Mathews.

And, after the loan is paid off, the savings generated by the reduced energy costs all goes toward the bottom line, he added.