University Medical Center at. Healthy Success: Hospital energy system showcases best practices. Feature Story

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1 Feature Story Healthy Success: Hospital energy system showcases best practices Guy Molinari, PE, LEED AP, Senior Vice President, Concord Engineering Group; Thomas Batten, PE, Project Manager and Lead Mechanical Engineer, Concord Engineering Group Courtesy Princeton HealthCare System. The University Medical Center of Princeton at Plainsboro is set within a 171-acre health campus that currently also includes medical offices and a skilled nursing and rehabilitation center; proposed other uses for the campus include pediatric outpatient treatment, adult and child daycare, senior independent living, assisted living, health and fitness, and a 32-acre public park. University Medical Center at Princeton in New Jersey is a leading teaching hospital and acute care facility with a national reputation for excellence. Established in 1919, it is a unit of Princeton HealthCare System (PHCS) and is affiliated with the University of Medicine and Dentistry of New Jersey Robert Wood Medical School, The Cancer Institute of New Jersey and The Children s Hospital of Philadelphia. Early in 2012, the hospital is due to be replaced by a $447 million new state-of-the-art facility, the University Medical Center of Princeton at Plainsboro (UMCPP), located just 2.5 miles from the center of Princeton. Designed by a team of internationally renowned architects and consultants, the new 636,000-sq-ft hospital will incorporate the latest green building technologies. Among its green features is an efficient on-site central energy plant that has the capacity to supply the facility with 100 percent of its heating, cooling and power. The project was developed by NRG Thermal LLC, a wholly owned subsidiary of Princeton-based NRG Energy Inc., which will also own, operate and maintain the plant. The planning District Energy / Second Quarter

2 and construction of this plant created an innovative model for securing financial support and operating campus energy systems that can be replicated on similar projects throughout the country. Making Every Dollar Count In 2005, PHCS presented its plan for the new UMCPP. It was an opportunity to build a hospital from the ground up with the most advanced medical services, easy patient access and room for future expansion. PHCS aimed to use green building practices while incorporating a variety of environmentally friendly and sustainable initiatives. To accomplish this, the company decided to outsource the financing, design, construction, ownership, operation and maintenance of its energy operations. NRG Thermal was selected for the job. After careful review and assessment, NRG determined the new hospital would benefit from its CHP+NRG package, a combined cooling, heating and power (CCHP) plant that supplies electricity while producing steam for heating and sterilization, and chilled water for air conditioning. A long-term energy services agreement established that NRG would provide electric and thermal energy to the hospital through a collateralized investment. This forward-thinking outsourcing decision freed up capital that would otherwise be required to finance the energy plant. The additional capital would allow PHCS to invest in what it knows best: delivering exceptional health care services. Outsourcing the energy plant freed up capital and allowed PHCS to invest in what it knows best: delivering exceptional health care. In executing a third-party designbuild-own-operate-and-maintain concept, NRG sought the expertise of Concord Engineering Group (CEG) of Voorhees, N.J., for its engineering and construction management services with a specialization in power plant and district energy plant projects. As the plant s engineer and construction manager, CEG provided NRG with a competitive construction management fee structure that, in combination with the hospital s initiatives and NRG s expertise in financing, developing and operating similar projects, served as a catalyst to move the project forward. The ability to integrate engineering and construction management from a single firm as a single point of responsibility was a significant factor in meeting scheduling and cost constraints for the $34 million design-build project. This unique approach toward construction of the CCHP plant, known as NRG Princeton Energy Center LLC, has been the key to its successful construction to date. All major equipment was prepurchased and prepackaged for delivery to the site, thereby minimizing installation and maintenance costs as well as accelerating the project schedule. By integrating engineering, construction and startup, NRG and CEG were able to meet the project s schedule and budget. This arrangement required that CEG share in the responsibility of all project aspects. The NRG- CEG partnership has resulted in lower overall installation costs for NRG as the owner-operator. The integrated approach unified responsibility, eliminated finger pointing and minimized change orders. Alternative funding was another component of the project s economics that made it feasible. A significant grant from the local utility, Public Service Electric & Gas, provided funding directly to PHCS for energy efficiency upgrades for the central plant and hospital HVAC systems. The project also received commitments for a $1.9 million Clean Energy Solutions American Recovery and Reinvestment Act Combined Heat and Power Program grant administered by the New Jersey Board of Public Utilities and the New Jersey Economic Development Authority (NJEDA), a $3 million Clean Energy Solutions Capital Investment (CESCI) Fund nointerest direct loan and a $2 million CESCI grant from the NJEDA. According to Barry S. Rabner, PHCS chief executive officer and president, the CCHP plant will have an estimated payback of less than five years with annual savings of hundreds of thousands of dollars. Third-party outsourcing to NRG, CEG s construction management approach and financial support through grant programs have established a proven best-practice model for executing major capital construction projects. Utilizing the Latest Technology NRG Princeton Energy Center will use a 4.6 MW Solar Mercury 50 gas turbine matched to a supplemental-fired heat recovery steam generator. For a turbine of its size, the recuperated Mercury 50 has the lowest emissions of any prime mover and the lowest heat rate compared to other turbines, with an electrical efficiency exceeding 38 percent. The high-temperature exhaust available for energy recovery made it an attractive choice to meet the needs of the 150-psig steam distribution system already designed by the hospital. The natural gas turbine requires a compressor system to boost the utility gas pressure, which varies significantly from winter to summer conditions. The seasonal fluctuations presented an opportunity for significant energy savings, since suction pressure has an exponential effect on compressor brake horsepower requirements. CEG worked with the compressor vendor to develop a controls strategy to minimize energy consumption of the parasitic load, which will contribute directly to the plant s generating capacity during periods when electrical demand is highest. The result is a system that has increased maintenance benefits and an expected payback within two years. A 1 million-gal thermal energy storage (TES) system is another unique aspect of the plant design that provides substantial operating energy cost savings, capacity for future load growth and useful operational flexibility. Economies of scale associated with large-capacity TES plants typically produce the most favorable economics. 8 District Energy / Second Quarter 2011

3 Courtesy NRG Energy Inc. The $34 million NRG Princeton Energy Center will be fully operational in 2012 when hospital construction is completed. This is especially relevant when installed during new construction when capital cost can be offset by capital savings associated with downsizing conventional chiller plant capacity. However, in order to meet the hospital s requirements, the chiller plant capacity was not reduced. The main benefit of TES in this case is the ability to offset approximately one-third of the hospital s total demand in a congested area of the PJM grid. During peak electric price periods, cogenerated electricity sold to the grid enhances TES system economics. Another benefit is the tank s ability to flatten thermal and electrical demand profiles, improving the overall performance of CCHP when used with a hybrid chiller plant. By itself, the cost of constructing the TES system yielded a simple payback of 10 years, which fell within the local utility s 15-year maximum required payback period and therefore was eligible for partial funding. If the capital credit for the equivalent additional chiller plant capacity provided by the TES system is incorporated in the analysis, the simple payback period drops to just under three years. Another plant design feature is the use of a deaerator feedwater preheater. Typically used in large utility power plants, this unit could result in adverse conditions such as coil steaming or gas-side condensation when used in a small system where there is a wide range of steam production. Proper selection of the unit was therefore important to avoid these operational issues and had to consider the actual range of exhaust temperature and load combinations. The preheater is expected to provide an increase in overall cycle efficiency of 2.5 percent and will help achieve an annual cycle efficiency greater than 65 percent higher heating value (HHV), which accounts for heat rate degradation over time. The peak overall cycle efficiency is expected to be above 77 percent HHV (86 percent lower heating value) with the heat recovery steam generator fully fired. One consideration in selecting the power generation, boiler and chiller plant equipment was the need to accommodate future load growth. The hospital had constructed the main patient tower with the ability to expand by two floors, which would increase the total heating, cooling and electrical loads by approximately 25 percent. The plant was designed with the ability to meet the future demand even with failure of major equipment such as a chiller or boiler. The resulting high initial capital cost of meeting the redundancy target placed further emphasis on energy efficiency to provide an economically attractive project. CEG and NRG evaluated several other technologies, including direct-contact heat recovery systems for the turbine exhaust on the back end of the heat recovery steam generator and packaged backpressure steam turbines. However, these technologies were not District Energy / Second Quarter

4 found to yield an attractive payback for this project. One important consideration regarding the application of energy conservation measures was coordination with the design and construction schedule of the hospital and its utility services. For example, evaluation of a backpressure steam turbine would have required increasing the distribution piping size throughout the hospital during an advanced stage of construction and would have had major schedule as well as financial impacts on the project. While specification of efficient equipment across its load range is important, control and operation of each of the components in the context of system performance is critical to minimizing long-term energy costs. The plant will use several coordinated layers of energy optimization software for control of the turbine generator and chilled-water systems. First, a proprietary dispatch software system will forecast market volatility and electricity prices at the local hub of grid operator PJM ahead of the utility s published locational marginal pricing based on weather, fuel costs, market behavior and historical data. The system will also model all thermal and power loads on both a 24-hour and seven-day day horizon. In real time, the system uses an adaptive model mapping load and market system outputs to make recommendations for operation of major equipment to maximize the economic benefit, including the charging and discharging rates of the system TES tank, operation of the hybrid electric and steam-fired chillers, and turbine operation while avoiding short cycling of equipment. The demand shift ability of the TES allows flexibility in targeting the highest electrical export prices, resulting in atypical operation when compared to conventional cost-avoidance strategies. In this way, the TES tank enhances the site s ability to export electricity, increasing the project s economic merit. The second layer of programming will include chiller plant optimization software based on the overall energy partitioning of the dispatch software. The wire-to-water control algorithms automatically modulate the chilledwater pumps, condenser water pumps and cooling tower fans to maintain a minimum kilowatt-per-ton ratio based on site load, temperature differential and outdoor air enthalpy. Variablespeed chillers were selected because of their ability to perform efficiently at lower condenser water temperatures, a condition that will occur frequently when the TES tank is charged at night. CEG selected chilled-water control valves for each of the hospital s airhandling units to achieve a site chilledwater temperature differential of 18 degrees F, which minimizes pumping horsepower. This high temperature differential is particularly critical and most difficult to achieve in off-peak conditions where the equipment will operate for more than 95 percent of the year. The CHP+NRG system provides multiple layers of redundancy in power provision. The CCHP design enhances power reliability by supplying electricity from four independent sources. Most hospitals are powered only through a main utility grid and backup generators that service crucial areas. The CHP+NRG system provides multiple layers of redundancy in power provision first System Snapshot: NRG Energy Center Princeton System Owner and Operator: NRG Thermal LLC Location: University Medical Center of Princeton at Plainsboro, N.J. Steam/Combined Heat and Power System Chilled-Water System Startup Year Full operation begins in 2012 (steam service for construction heating Full operation begins in 2012 (chilled-water service began in 2010, full service to hospital begins 2012) was available in late 2010, full service to hospital begins 2012) Total Square Footage Served 636,000 sq ft 636,000 sq ft Plant Type Combined cooling, heating and power (CHP+NRG ); Variable-speed chillers and distribution with Solar Mercury 50 gas turbine with heat recovery steam generator and 1 million-gal chilled-water thermal energy conventional boiler plant storage and advanced wire-to-water control Plant Capacity 50,000 lb/hr steam, 4.6 MW electricity, 3,000 tons chilled water, 10,000 ton-hr TES 6 MW emergency diesel generators Number of Boilers/Chillers 3 3 Fuel Types Natural gas, fuel oil Electric, steam Distribution Network Length Approx. 3,000 ft Approx. 3,000 ft Piping Type Insulated carbon steel Insulated carbon steel, ductile iron direct-buried to TES Piping Diameter Range Up to 10 inches Up to 18 inches System Pressure 150 psig N/A System Temperatures 366 F steam, 200 F condensate 40 F supply/58 F return Source: Concord Engineering Group 10 District Energy / Second Quarter 2011

5 from the on-site gas turbine, backed by two independent, full-capacity power feeders from the grid, with an additional source of power available from three 2 MW diesel generators. The turbine, which has black start capability, can provide redundancy even without the continued use of the diesel generators. The hospital will literally be a powerhouse, says CEO Rabner of PHCS. The environmental benefits of the plant are substantial, eliminating 18.1 million lb of annual carbon emissions. According to Bob Henry, NRG senior vice president of business operations, Efficiency is the key. We ll get about 70 to 73 percent versus 30 to 35 percent from a traditional power plant. Every source of energy is used to the extent possible, which benefits both the hospital and the environment. New Jersey officials, including the state Board of Public Utilities, have welcomed the new CCHP plant and its clean technology benefits, in line with the state s commitment to reduce emissions and increase energy efficiency by Plainsboro Mayor Peter Cantu says the plant will set a new higher energy efficiency standard for local developers. The New Jersey Hospital Association also applauds the plant as a model for hospitals seeking to improve operational efficiency. NRG Energy Center Princeton is expected to be fully functioning in 2012 when the construction of the six-story hospital is complete. The plant is already delivering steam and chilled water for construction heating and cooling. Outsourcing its energy center allows PHCS to focus on its core mission of providing health care while delivering a costeffective operation that benefits the surrounding community and the environment. As CEG President Michael Fischette concludes, Creative third-party financing partnerships and innovative engineer/procure/construct solutions eliminate barriers for large-scale facilities interested in reducing costs while fostering environmental stewardship. Guy Molinari, PE, LEED AP is senior vice president of Concord Engineering Group and director of operations for the engineering, commissioning, construction management and design-build sectors. Molinari has more than 30 years project management experience with industrial, commercial and power generation projects. Currently he is senior engineering and construction manager for the central utility plant and cogeneration project at the University Medical Center of Princeton at Plainsboro, N.J. Molinari can be contacted at gmolinari@ceg-inc.net. Tom Batten, PE, is project manager and lead mechanical engineer, Concord Engineering Group. Batten has directed interdisciplinary teams through all phases of master planning, design, construction and operational startup of cogeneration and central utility plant projects. He possesses extensive plan and specification and design-build experience in the fields of institutional and commercial heating, cooling and power generation. His address is tbatten@ceg-inc.net. Increase your visibility. Reserve your advertising space now to be sure your company is seen in print and online in front of industry professionals around the world. The City of Surrey, British Columbia, Canada is a place of innovative transformation and accelerated growth where the future is limitless and possibilities are endless. If you are excited about helping to build the city of tomorrow and you share our values of integrity, service, teamwork, innovation and community join us today. Energy Manager In this newly created position, you will champion energy strategies and projects to support our efforts to achieve our clean energy vision and goals. You will lead the City s District Energy initiatives, including the implementation of the City s first district energy system, which is focused on meeting the needs of civic facilities under construction in our City Centre. Contact Tanya Kozel, tanya.idea@districtenergy.org, (410) today! If you feel you have what it takes to be part of a great team, please visit us on-line for full details and to apply: District Energy / Second Quarter