Boston Medical Center, the busiest trauma and emergency services center in New England, went live on April 24 with a $15 million, natural gas-fired, 2-MW combined heat and power plant (CHP or cogeneration) that is expected to save the hospital about $1.5 million on its energy costs annually.
The cogeneration facility – about the size of a tractor trailer – operates at 70 percent efficiency. In addition to powering and heating much of the hospital, the facility will also serve as a backup power source for city and state emergency communications.
BMC is the only major teaching hospital in Massachusetts that currently has “black start” capability, meaning that if the electric grid goes down, the hospital can restart the cogeneration plant and heat and power its inpatient units on an “island” for months at a time, as long as it has a supply of natural gas. The cogen plant is located on the roof of the Yawkey Ambulatory Care Center, high above any potential floodwaters.
The plant – manufactured by Caterpillar and designed by Engineered Solutions – will supply more than 41 percent of the hospital’s electricity and has the capacity to meet 25 percent of peak electricity demand at any given time.
By reusing trapped heat for hot water, humidification, and maintaining room temperature, the hospital will lower costs by reducing its need for steam heat by an estimated 44,000 pounds annually. Cogeneration also is expected to reduce electric grid consumption by more than 16 million kWh a year.
Partial funding for the plant came from a $3.7 million grant from the Massachusetts Department of Energy Resources’ Community Clean Energy Resiliency Initiative. The Boston Public Health Commission partnered with BMC in securing the grant.
In addition, regional utility Eversource provided BMC with financial incentives to bring cogen to the hospital campus. In the last four years, Eversource and BMC have partnered on more than 30 efficiency projects, achieving more than 8 million kWh in annual energy savings, or roughly 5 percent of the hospital’s total electricity usage.
“BMC can make a strong case for being the greenest and most resilient hospital in Boston,” said hospital CEO Kate Walsh. “For us, increasing efficiency and resiliency makes financial and operational sense. Cogen will save about $1.5 million in energy and heating costs, which are resources we can spend on patient care, instead of utility bills.”
“We’ve learned lessons from Hurricane Katrina and Sandy, which devastated the health care infrastructure in their communities,” said Bob Biggio, SVP for Facilities and Support Services. “Hospitals that had cogen were able to stay open and care for patients, while those without cogen were forced to evacuate.
“As the largest safety-net hospital and biggest trauma center in New England, we have an obligation to protect our patients in a natural disaster.” Biggio continued. “Cogen gives us the ability to continue to care for the most vulnerable population in our city, even when the electric grid goes down.”
The hospital has taken other important steps toward resiliency: installing new generators on floors of patient care buildings; creating cross-building critical infrastructure connections, so when one patient building loses power, it can connect to the generator in an adjacent building; and programming elevators to stop short of the lower floors to maintain patient care in the event of a flood.
BMC, which was already cutting emissions by 50 percent as part of a clinical campus redesign, also announced a solar power purchase agreement last fall with MIT and the Post Office Square Redevelopment Corporation.
The solar purchase is equivalent to 100 percent of BMC’s projected electricity consumption, making BMC the greenest hospital in Boston and on pace to become the first carbon-neutral hospital in New England upon completion of the campus redesign in 2018.