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Since 2009, the Penn State Health Milton S. Hershey Medical Center has been implementing a multiphase energy efficiency program. Six years into the program, Kevin Kanoff, the center’s campus energy engineer, knew the chiller plants were efficient – but he believed they could be improved. Kanoff performed an engineering site assessment (ESA), which proved him correct: optimizing the chiller plants across the campus would deliver significant energy savings.
Kanoff installed an HVAC optimization platform in June 2016; immediately, he found that the center’s 12 chillers were running at peak efficiency, saving electricity costs, using less water, and reducing carbon emissions. In fact, annual energy savings were found to be almost 4.2 GWh/year, roughly 1 GWh more than expected, and campus energy intensity dropped 4%.
The plant optimization project was not a small task. The Milton S. Hershey Medical Center serves more than 1.2 million patients and employs 10,000 people. The campus – which includes two hospitals, five institutes, and Penn State University’s College of Medicine – has 2.6 million square feet of air-conditioned building space served by three chiller plants: a central plant of eight chillers and two satellite plants with two chillers each that provide a total of 14,200 tons of cooling. The system also includes a 1.4 million gallon chilled-water storage tank.
The previous phases of the energy efficiency initiative had reduced the campus’s energy intensity by 20%; now, Kanoff had to find a way to squeeze out additional efficiencies. The ESA showed that optimization would provide the additional energy savings he sought.
The Solution: Analytics and Relational Controls Provide Real-time Data and Automatically Adjust for Efficiency
First, Johnson Controls installed variable-speed drives on pumps and fans, adding power meters and sensors for precise measurement of all system components and fully automating the manual plant.
Because the security of data systems is a high priority for a medical facility, Kanoff made sure his vendors worked closely with the center’s IT staff to ensure all data going from the plant in Hershey to the cloud-based platform he had chosen would be absolutely secure.
Kanoff chose Optimum Energy’s OptiCx platform and OptimumLOOP relational control software, which analyzes HVAC data, pinpoints what needs to be done to improve efficiency and stability, and adjusts equipment in real time.
The relational control automatically stages all the chillers and the chilled-water storage tank as an integrated whole, choosing the best option based on equipment efficiency and demand for cooling. The software continuously collects data from Johnson Controls’ Metasys BAS about plant operations, outside conditions, and hundreds of other parameters, and calculates how to operate for peak efficiency and operational stability. It then adjusts the set points of pumps, fans, and other components in real time.
The implementation at all three plants went smoothly, says Kanoff:
“From a building environment perspective, the system went through start-up seamlessly. Critical patient areas were not compromised.”
The project reduced the center’s energy intensity by 4%, which translates into electricity cost savings of about $300,000 per year. The center’s energy intensity has now been reduced by 24% over 2009 levels.
“We initially projected an energy savings of 3.4 GWh annually, but the electric utility’s evaluator found that savings are actually 4.16 GWh annually,” says Kanoff. As a bonus, the medical center earned a onetime $416,000 incentive from the utility.
The project has an estimated ROI of just 4.3 years (including the incentive).
The center has significantly decreased its carbon footprint. The optimization project has saved 7 million pounds of CO2 emissions through March 2017. It is also saving more than 1.4 million gallons of water per year as a result of the reduced energy consumption.
“Through this project, we are more aware of energy efficiency and savings,” said Kanoff. “It’s helping the team see the bigger picture—we’re not just providing chilled water, but we’re doing it as efficiently as possible and, ultimately, saving money.”
Optimization also streamlined chiller operations that staff had performed manually without having a complete picture of the system.
“The team still monitors the chillers and verifies the data, but now they do it with the new control system,” says Kanoff, noting that facility operators had been skeptical at first. “Now they’re able to accomplish more, managing and operating the entire plant without the old white-knuckle approach.”
Plant efficiency improvement: Annual average plantwide efficiency went from 0.828 kW/ton to 0.646 kW/ton.
Annual project utility savings includes:
- Electrical energy savings: 4.16 GWh/year
- Electrical demand reduction: 874 kW
- CO2 emissions reductions: 3,220 tons/year
- Water use savings: over 1.44 million gallons/year
Annual projected financial savings:
- Electricity cost savings: $300,000/year
- Estimated ROI: 4.3 years (includes incentive)