A steady, energetic humming sound heard on the east side of the Christiana Care campus is broadcasting good news about Christiana Care’s growing commitment to environmental stewardship and energy efficiency.
The buzz is coming from a new energy building, built next to the central utility plant to house a new combined heat and power system designed to put previously wasted heat to beneficial uses at Christiana Care.
Inside the building, an 18-cylinder natural gas engine and an electrical generator runs 365 days a year to create 2 megawatts of electricity, producing 16,000 megawatt hours per year. In conventional electricity creation, the heat generated by this power production would be a wasted byproduct vented to the atmosphere. But with the combined heat and power system now in place, that recovered heat is captured used to produce steam and hot water for the HVAC system, laundry, kitchens and medical sterilization process.
“We estimate we will achieve $1.2 million in annual savings now that we have the combined heat and power system online,” said Bob Mulrooney, vice president of Facilities and Services. He added that this green technology is expected to generate more than 30 percent of the annual electricity needs of Christiana Hospital.
The new system will also help to reduce regional power plant emissions.
“Because of new efficiencies in the combined heat and power electricity production, an estimated 21,000 fewer pounds of nitrogen oxides are released into the atmosphere each year, and 120,000 fewer pounds of sulfur oxides,” said Jeff Krebs, manager of Mechanical Engineering. Both of these chemical compounds are associated with the negative health effects of air pollution. “The nitrogen oxides emissions reduction is equivalent to taking 1,100 cars off the road.”
A conventional power plant is about 40 percent efficient when creating electricity, whereas a combined heat and power system achieves upwards of 80 percent efficiency, said Krebs. Because of this efficiency, the Delaware Department of Natural Resources and Environmental Control (DNREC) provided a $1 million grant for the project, reducing Christiana Care’s design and construction costs to $5 million.
The U.S. Office of Energy Efficiency and Renewable Energy has encouraged hospitals to consider combined heat and power technology, making the case that it is a “cost-effective, near-term opportunity to improve our nation’s environmental and economic future.”