Balance of power
When The Reading Hospital and Medical Center teamed with Z&F Consulting for a physical plant commissioning project in 2003, the two didn't realize the project would lead to a cogeneration facility and an innovative energy approach.
Cogeneration is part of a comprehensive financial and energy strategy for the hospital. The strategy takes advantage of free-market energy purchases, dual-fuel central plant flexibility, and in-house energy generation for long-term benefits and significant cost savings.
Conscientious cost controls
Founded in 1867, The Reading Hospital and Medical Center is a nonprofit healthcare center providing community-based services from its 36-acre Berks County, Pennsylvania, campus and 20 county locations. The hospital staff numbers nearly 6,200, with 680 physicians in 50 clinical specialties. Annual admissions number 32,000.
The hospital has been recognized for its lower-than-average patient costs. Faced with similar budget constraints as other U.S. healthcare providers, the hospital implemented conservation efforts to limit energy spending. Unsatisfied with the results, the hospital pursued proactive energy planning.
In 2003, Z&F Consulting of Wayne, Pennsylvania, was engaged by the hospital for construction administration and commissioning of new physical plant equipment. The plant provides power to two million square feet of campus buildings. The Z&F team brought to the project its combined knowledge of mechanical, electrical, plumbing, and critical systems engineering. Led by principals John W. Zabilowicz, PE, LEED AP, and Brian M. Flynn, PE, LEED AP (co-author of this article), the project put equipment in place to equalize The Reading Hospital's energy load demand and prepare it for the future.
Specifically, Z&F provided installation oversight, startup, and commissioning of two 1,300-ton steam-turbine chillers; three 900-ton electric-driven chillers; one 30,000 lb/hour high-pressure, dual-fuel-fired boiler; auxiliary air-handling systems; a direct digital control system with 24/7 remote monitoring; and a 3,000-gallon fuel oil system.
The key to this project initially was implementation of dual-fuel equipment that lets the hospital choose and bid natural gas or fuel oil, depending upon market pricing. In addition, campus backup generators were enrolled in utility payback programs. Together, the measures resulted in a net revenue reduction of 15% of the hospital's annual electric costs.
In 2007, The Reading Hospital again commissioned Z&F to perform a feasibility study to further reduce electric costs. The study evaluated alternative fuels, solar panels, and cogeneration. Cogeneration uses an internal power plant to simultaneously generate both electricity and useful heat. Whereas a typical power plant would release waste heat through a cooling tower, cogeneration recaptures waste heat and re-uses it, making cogeneration a thermodynamically efficient practice.
The study was a systematic and detailed undertaking. Z&F used proprietary X-Load software developed by Flynn and written specifically for the Reading Hospital project. The software analyzed the hospital's energy usage and cost data in 15-minute increments for a full year. The software obtained an accurate picture of energy-grid costs and compared those values to the costs of purchasing energy on the spot market, purchasing a combination of spot energy and cogenerating, and purchasing a prepackaged power contract as a standard utility customer.
Cogeneration proved to be the most cost-effective energy-reduction plan. The equipment installed in 2003 produces and utilizes large amounts of high-pressure steam, which can be extracted and used to produce hot and chilled water. Thus, with appropriate equipment already in place, cogeneration made sense. Schematic design of a cogeneration plant began in April 2007.
Energy market in Pennsylvania
A major difference in the Z&F approach at The Reading Hospital is the opportunity to take advantage of Pennsylvania's free-market electricity bidding process. Rather than base-loading the cogeneration plant (i.e., generating as much as capacity permits) and making up the difference in purchased power, the approach lets the hospital buy when prices are low and self-generate when prices are high.
In 1994, Pennsylvania's electricity rates were capped. Beginning in 2010, however, the caps will expire in Berks County and electric rates will significantly increase. The Reading Hospital's properties straddle the jurisdictions of two energy providers. Its main campus is serviced by Metropolitan Edison Company, while satellite locations fall under the auspices of PPL Corporation. PPL prices are expected to rise 35% on January 1, 2010, from the $59 per-kilowatt-hour capped rate to $98 or more. Metropolitan Edison Company's rates will increase at the end of 2010 from $66 per kilowatt hour to $120 or more. The major factor in surviving this energy deregulation will be the ability to conserve energy. If demand reduces, then electricity prices will moderate.
In Pennsylvania, utility companies bid electricity capacity on the free market at prices that fluctuate daily according to supply and demand. The least expensive price is dispatched first, with prices increasing as the day progresses. Electricity costs look like a bell curve, highlighting peak usage periods and highest prices at the top of the curve. Low-cost electricity may be available, for example, in the early morning hours when demand is lowest; during peak business hours it is priced highest.
The Reading Hospital, and hospitals in general, can capitalize on free-market energy purchases because a hospital is a 24/7 operation-it doesn't have lower energy-usage periods. Since its load doesn't decrease, a hospital can realize cost savings by purchasing electricity at night when rates are lowest.
A cogeneration plant clips the tip of the bell curve. The Reading Hospital can purchase electricity at low rates, and when costs exceed what the hospital wants to pay, it can generate its own electricity via the cogeneration plant. Generating on-site means no energy is wasted, because waste heat is re-used to heat and cool the hospital.
Z&F also wrote a software program that incorporates real-time cost-analysis data into the hospital's building automation system. The system modulates the cogenerating plant's operation based on electricity prices.
As mentioned, The Reading Hospital's new cogeneration plant generates steam and domestic hot water for heating. The plant consists of two natural-gas-fired, turbine-driven generators, each with net capacity of 5.0 MW after parasitic loads. The generators are coupled to a 700-horsepower waste-heat boiler to capture heat from combustion gases. Also included are waste-heat economizers for boiler-feed water preheat and domestic water preheat. This design reduces the hospital's carbon footprint by 35% and reduces emissions of carbon dioxide, nitrous oxide, sulfur oxide, and particulates.
The cogeneration plant was initially designed within the hospital's existing central plant. During design development, however, it was deemed more appropriate to move the plant to a separate building, and Z&F brought Array Healthcare Facilities Solutions, of King of Prussia, Pennsylvania, onto the team for architectural design. Array Project Manager Herman Van Fleet III, AIA, commented, “The project represents an opportunity to develop an environmentally conscious prototype.”
The plant's new location is on the main campus, adjacent to the hospital's emergency department. This location accommodates future expansion potential and allows the hospital to install two generators rather than a single unit, improving efficiencies for the present and future.
The Reading Hospital and Medical Center's cogeneration plant is expected to be online and fully operational in the fourth quarter of 2010, to coincide with Metropolitan Edison's rate increases.
Return on investment
The combination of generation and capture of waste heat to produce high-pressure steam is predicted to result in a net usage of 87% of energy expended, compared to 35% when generating alone. Based on an initial investment of $9.1 million, the plant will realize a 30% return on investment, or simple payback of four years.
Incorporation of a cogeneration plant at The Reading Hospital and Medical Center not only reduces energy expenses and makes the hospital more efficient, it also reduces per-bed costs and, consequently, reduces overall medical costs for patients. The project represents a re-evaluation of an existing technology and using it to shape the needs of a healthcare provider. HD
Brian M. Flynn, PE, LEED AP, is a founding principal of Z&F Consulting and holder of several patents. He can be reached at 610.995.2988, x223 or
firstname.lastname@example.org. Amanda Gibney Weko is a writer and communications consultant, and chair of the AIA Philadelphia Communications Committee. She can be reached at 856.607.9657 or
email@example.com. Healthcare Design 2009 August;9(8):20-28