Electrical outages are a nuisance anywhere; in a state-of-the-art digital hospital, patient care will stop. Hospitals typically have an emergency diesel-powered generator that kicks into action in the event of a power loss. Code requires that the emergency generator start within 10 seconds but only generate enough power to allow safe egress of occupants in the event of a grid outage.
Most recently, prolonged grid outages have been caused by natural disasters like Hurricane Katrina and Rita along the Gulf Coast and by manmade outages like the 2003 power blackout in the northeastern United States and the Sept. 11, 2001, terrorist attacks. These real-world examples demonstrate what can happen when we lose power for long periods. One study investigating the reliability of emergency generators during the northeast blackout showed that nearly all started within the required 10 seconds, but more than 60 percent failed to keep running.
But today, a digital hospital needs more than emergency power to get people out of the hospital. It needs an on-site energy system to keep 100 percent of the hospital operational for days, not hours. There is a better way: An on-site combined heat and power (CHP) system can generate all power needed for the hospital and use the waste heat from the generator to produce all required chilled water for cooling and steam for heating. A CHP system also enhances the efficiency and reliability of the hospital’s systems and significantly reduces emissions compared to a hospital being fed from the grid alone.
When Shands HealthCare decided to build a new cancer hospital in hurricane-prone Gainesville, Fla., it knew it needed an efficient, reliable and environmentally clean energy source to keep the hospital operational in the event of a power disruption. It also decided to find an energy partner to own and operate the on-site energy system to provide electricity, chilled water and steam. After a competitive solicitation, Shands selected Gainesville Regional Utilities (GRU), the local municipal utility, to finance, design, build, own, operate and maintain an on-site energy center as part of an innovative 50-year energy agreement.
Burns & McDonnell is one of seven companies — and the only engineering and construction firm — selected by the U.S. Department of Energy in 2004 to develop on-site energy CHP systems. The GRU South Energy Center at the Shands Cancer Center is the second such plant designed by Burns & McDonnell. The first went into operation in 2006 at the Dell Children’s Medical Center of Central Texas.
“At a time when the nation’s power grid seems increasingly vulnerable to interruption, an on-site power source offers the improved reliability that can be achieved by running in parallel with the grid. It also has the ability to disconnect from the grid without disruption of service to the hospital or facility,” says Ed Mardiat, principal and director of CHP development for Burns & McDonnell. “In addition, hospitals have grown more reliant on digital technology, such as MRIs and CAT scans, which are extremely sensitive to power quality and voltage fluctuations. That means that reliable and quality power is more important than ever.”
The GRU South Energy Center, which went into service in February 2009, efficiently converts fuel into useful energy. The Department of Energy report “Combined Heat and Power: Effective Energy Solutions for a Sustainable Future” defines CHP as “the concurrent production of electricity or mechanical power and useful thermal energy (heating and/or cooling) from a single source of energy. CHP is a type of distributed generation, which, unlike central station generation, is located at or near the point of consumption. Instead of purchasing electricity from the local utility and then burning fuel in a furnace or boiler to produce thermal energy, consumers use CHP to provide these energy services in one energy-efficient step. As a result, CHP improves efficiency and reduces greenhouse gas (GHG) emissions.” The GRU South Energy Center is designed and sized to meet the hospital’s thermal baseload demand.
In this case, compared to a traditional central generation plant fueled by fossil fuel, the natural gas-fired CHP system produces 95 percent less nitrogen oxides, nearly 100 percent less sulfur dioxide and 58 percent less carbon dioxide. This carbon dioxide reduction is equal to the annual carbon stored by 5,446 acres of pine and fir forests or the carbon emissions of 4,365 passenger vehicles per year, as calculated by the U.S. Environmental Protection Agency CHP Emission Calculator.
In Gainesville, the GRU South Energy Center, a three-story, 40,500-square-foot facility, can provide 4.3 megawatts of power, 800 bhp of steam and 2,400 tons of chilled water. It has been designed to accommodate future expansion of the hospital and future build-out of the Shands site campus.
Shands administrators chose GRU as their energy partner so they could focus on their core business of patient care. In turn, the arrangement allows GRU to focus on its core business of energy services. The innovative business agreement between Shands and GRU allows any excess power generated by the CHP system to be sold to the grid, with any proceeds being shared by both parties.
“The CHP plant is only part of the hospital’s power system. There are two independent grid feeds from GRU’s power distribution system, along with two on-site, diesel-powered emergency generators,” Mardiat says. “There’s a lot of flexibility in how GRU’s operators can configure this plant to keep it up and running.”
For more information, contact Ed Mardiat, 816-822-3344.