NJHEPS Energy Case Studies -- Short Takes
Best Practices, 2003 - 2004

By taking advantage of new technology and the recent deregulation of energy prices in the region, Princeton is hoping to cut down its energy costs -- possibly saving more than $1 million each year out of the roughly $10 million spent on energy.

Starting in August 2003, the University has taken advantage of fluctuations in the price of power in the local area to save money. At night, when electricity demand is usually lowest, the University can get power from the local grid for very low prices and sometimes for free. But during the day, the prices can hover around $100 per megawatt-hour and spike to $1,000 per megawatt-hour on hot summer days. When it is cheaper to take power from the outside grid rather than produce its own, Princeton scales back its power production, using a complex algorithm to determine how much power to make on campus and how much to buy. The algorithm takes into account current and predicted prices of both fuels and electricity as well as current and predicted weather. In addition to adjusting the co-generation plant's output as power prices change, engineers can also switch which fuels are used to power the plant.

For example, when electricity is cheap, the University uses electrically-powered chillers to make cold water for the campus. But during the day, when electricity is more expensive to buy, the University makes more of its own in the cogeneration plant, using the steam produced to power steam-driven chillers.

Just the technique of switching power sources as needed is expected to save the University several hundreds of thousands of dollars. Additionally, the University soon will take this concept to the next level by using a giant "thermal battery" to store night-time cheap energy for the next day. Beginning in 2004, the University will construct a 2.6 million gallon tank that it will cool to near freezing temperatures each night when power is least expensive. Then, during the day, the cool water will be pumped out as needed. In addition to cost savings, thermal storage brings additional benefits: one national study found that thermal storage reduces greenhouse gas emissions by 5-25%, compared to standard technologies--depending on local differences between the mix of power plants used to generate electricity by day and by night. Princeton, therefore, can also expect its thermal storage equipment to help reduce its greenhouse gas emissions. (Flory, John, January 1995, "TES Reduces Source Energy Use and Air Emissions", ASHRAE 1995 Winter Meeting, Seminar 10).

Contact Edward Borer (609/258-3966, etborer@princeton.edu), manager of Princeton's mechanical systems, for more information.

Middlesex County College: Involving Students in Lighting Research

The Middlesex County College Biology Club not only studies life on Earth -- they also have taken steps on campus to help our ecosystem and lighten human impacts on the planet. Under the leadership of Professor Robert Colburn, Club President David Leon lead a cadre of students in monitoring light usage in 2 classrooms. Their reporting helped Middlesex decide that it would be cost-effective to install automatic lighting sensors, which turn lights off when no one is in the room. Further confirmation of just how wise a decision this would be came from the work of NJHEPS-funded intern Calvin King. He discovered and installed testing devices that documented the energy that would have been saved if lighting sensors had been in use. These devices made the case clearly and graphically -- in beautiful color-coded graphs that spelled out the energy and cost savings.

Calvin King also researched the equipment needed to switch over to these motion-detecting sensors, and helped Middlesex apply for SmartStart energy subsidies to support the financial outlay of purchasing the sensors. Because of this substantial student work, David Fricke, Director of Purchasing & Inventory at Middlesex, was able to purchase over 100 of these energy-saving lighting sensors for the entire campus, and a SmartStart subsidy application for these sensors submitted and approved.

Rowan and CAES, Rutgers: Involving Students in Audits and Assessment

CAES (Center for Advanced Energy Systems, caes.rutgers.edu), Rutgers University, has utilized students meaningfully and successfully to monitor, assess, and report on building energy usage and energy progress. Students in engineering and related fields have worked through CAES to provide energy services and advice to small and medium-sized manufacturers, gaining hands-on experience in energy and waste auditing in industrial settings. Students perform audits, learn about applied research and practical engineering analysis, and work with CAES staff to rigorously research "on the ground" engineering issues. Rutgers facility staff, the student group RUSustainable, and CAES are working together to put together a project to utilize the skills and expertise of CAES and its cadre of students to improve energy efficiency at Rutgers campuses.

In Fall 2003, students at Rowan gained practical skills and course credit as they advanced energy progress at their institution. Dr. Peter Jansson, Assistant Professor of Electrical and Computer Engineering, led a small group of students in an NJHEPS-supported special section of the engineering program's required Junior-Senior Clinic. In this multi-disciplinary engineering project, students performed energy audits of several Rowan buildings, learning the many aspects of performing this service (gathering data, calculating costs and benefits, making informed energy recommendations, etc.) from Al Lutz, a skilled and experienced energy consultant. Students gathered data weekly, using a template designed by Mr. Lutz, and significantly contributed to the data available to Rowan's facilities personnel. They moreover jointly wrote a report to Rowan's Energy Review Panel, ensuring that as they gained useful skills, these students also helped Rowan make better-informed energy choices. (See below for more information on Rowan’s Energy Review Panel). During their second presentation, these eager and concerned researchers, through careful observation and enhanced experience with Rowan campus life, came up with three to four times the energy savings for Rowan Hall as an earlier "professional" audit. These results are soon to be published in the Journal of the American Society for Engineering Education.

Rowan University: Energy Review Panel Creates Synergy and Progress

At Rowan, an Energy Review Panel brings together students, faculty, facilities personnel and administrative decision-makers to regularly consider energy decisions and policy options. The Comptroller and a Facilities Vice-President are on the committee, ensuring that decision-makers’ concerns are heard early in the energy project design process. The Panel also serves as a vehicle for involving broad expertise in generating and vetting ideas, adding immensely to the soundness and credibility of the projects the ERP approves. Some results:

• Enhanced communication between facilities planning, facilities management, and financial decision-makers, which is advancing the implementation of high performance design at Rowan.
• A college commitment to implement sub-metering for all utilities, and an expertise-filled research effort to find the best options.
• Developing outside partnerships (e.g., the US EPA’s ENERGY STAR, NJHEPS).
• Solid and quickly-endorsed plans for chilled water plant and cogeneration plant upgrades.
• Generating, researching and securing approval and funding for over 20 diverse projects involving over $90,000 in SmartStart subsidies (lighting, lighting controls, variable-frequency drives, and premium motors).
• Increased involvement and contributions from faculty and students.

The College of New Jersey: DC and AC Solar Go Head-to-Head

At a large TCNJ building, Nextek will be installing a solar-assisted lighting system. With their Direct Coupled™ system, the flourescent lights are powered by both the solar panels and the utility grid. This is one of the most efficient ways to use solar electricity in a commercial and industrial setting.

In this system installation, the flourescent light ballasts are replaced with high-efficiency DC ballasts. These ballasts are then powered by a centrally-located NPS-1000 DC power supply. The NPS-1000 power supply takes AC power from the grid, converts it to DC and adds it to the DC power from the solar panels. This means that the system uses ALL of the solar energy and some from the grid (if needed).

A 2 kW Nextek system will be installed along with a 2 kW conventional solar system. The conventional system will convert the solar energy to AC power and send the power directly to the grid, also reducing the electricity usage, and cost, to the building.

Nextek is seeking to demonstrate that their DC-based system is considerably more efficient than the conventional system because it uses the power where and when it is produced, rather than converting it AC and sending it to the grid. The BPU is supporting this pilot project, and more support may be forthcoming for this technology if it proves to be reliable and efficient. More information is at www.NextekPower.com, or call Mark Robinson at (603) 305-1942.