Schools and universities have struggled for many years with the rising cost of energy. The recent energy crisis in California put a new edge on this already important issue. The blackout in August that plunged eight northeastern states and part of Canada into darkness accentuated awareness of the need for education institutions to improve the reliability of their own energy infrastructure and reduce operating costs.
Maximizing core systems
Schools must maximize the efficiency of their core systems — HVAC, lighting and controls. Exponential improvement in these technologies over the years has allowed schools to improve the reliability and cost-effectiveness of these systems.
As the management and flow of data have become more important to the academic and administrative functions of education institutions, schools also must consider establishing uninterruptible power capability in the form of battery backup to enable an orderly shutdown of computer servers in the event of a power outage. Standby systems employ diesel-engine generators that provide power for critical systems in the event of a prolonged outage. Recent advances in standby power technology have decreased the size and installation cost of these systems.
An added benefit to developing a comprehensive standby power strategy is the issue of power quality. Standby systems can be engineered to detect voltage irregularities and power surges, kicking in automatically to protect critical systems.
Colleges and universities have the opportunity to achieve energy independence. Many institutions have the need to protect valuable research, not only for its own sake, but also because it represents a significant source of funding. This creates a critical power-quality requirement and raises the liability associated with a power outage.
Poor power quality characterized by voltage sags, harmonic distortion and background electrical “noise” wreaks havoc with sensitive digital electronic equipment and risks loss of valuable data. A power outage can destroy years of research. At the same time, aging infrastructure and the rising costs of electricity and fuel are consuming a greater portion of institutions' operating budgets.
A standby power system is one solution to reliability problems, but there is a more comprehensive solution. The year-round need for thermal energy and high-quality electric power creates the opportunity for colleges and universities to install a cost-effective, on-site power generation system.
On-site cogeneration uses proven technologies to produce electricity and thermal energy heat from a single fuel source, enabling institutions to achieve greater reliability at lower cost. Cogeneration provides the benefit of low-cost thermal energy and reliable power generally at a lower cost per kilowatt hour than traditional utility supply.
In recent years, cogeneration facilities have improved dramatically with unit size, occupying a smaller footprint; efficiency, using less fuel to produce more energy; reduced emissions; and, most important, lower capital costs. Combustion turbines and engine generators can operate using natural gas or diesel fuel, as well as landfill gas. Units range in size from 5KW to 16,000 KWe for single-engine generators with turbines ranging from 1,500 KWe to 22,000 KWe.
The new cogeneration systems also offer flexibility in system configuration to meet an institution's particular needs and budget. A system can be designed in parallel with the utility to supply partial loads. It may be designed in an islanded configuration, which operates independently from the utility. This type of setup usually includes redundancy, providing for extra units to take over in the event of failure (or offline maintenance) of the main units.
The system also can be designed in islanded mode with utility backup, which enables the plant to operate independently of the utility under normal conditions, with utility backup in the event of a catastrophic failure of the on-site plant. The most reliable system available, it may be appropriate for certain high-level research institutions.
Most college and university cogeneration plants are 5 to 25 MW in size, providing electricity and thermal energy, typically steam, hot water and chilled water to existing campus distribution systems. In many cases, the implementation of cogeneration is a timely decision in terms of creating new physical-plant assets.
A turnkey approach
There are various ways to go about pursuing cogeneration. Some colleges and universities use a conventional general contracting approach, awarding separate contracts for design, engineering and construction.
Others opt for a design-build and operate (DBO) approach carried out by a “turnkey” contractor/engineer/operator. The latter approach provides a single point of contact, interaction and control, freeing the institution's facilities engineers from the day-to-day details, and affording greater opportunities to introduce and incorporate elective elements into the design and construction.
In the DBO approach, the contractor/operator is responsible for coordinating the design disciplines and overseeing all aspects of the design process with a focus on designing and constructing for long-term operation. Essentially, this life-cycle approach focuses the DBO firm on the best solution for the long-term because of its ongoing operating role. Typical responsibilities may include coordination of mechanical, electrical, structural and civil engineers; equipment manufacturers; acoustical consultants; and emission-control consultants. The contractor may be responsible for design-quality control, review and approval of all design components, as well as management of the construction process itself. The contractor also may be responsible for obtaining air-quality permits and negotiating utility connections.
If advantageous, construction may be phased to allow the institution to preserve capital resources while building a thermal and electrical plant that provides a reliable and economic source of energy. Once the project is completed, the contractor/operator may staff the new plant, or the institution could operate it if it has sufficient internal resources and expertise.
In a climate of rising energy costs and uncertainty over the reliability of the power grid, education institutions must re-evaluate their ability to cope with power outages and fluctuations. Today's improving technologies and large-scale construction/facility service companies offer schools and universities a greater incentive than ever to increase their energy independence.
Martin is executive vice president for EMCOR Energy & Technologies, Norwalk, Conn.
New cogeneration systems offer flexibility in system configuration to meet an institution's particular needs and budget. The types:
- IN PARALLEL
A system can be designed in parallel with the utility to supply partial loads.
A system can be designed in an islanded configuration, which operates independently from the utility. This type of setup usually includes redundancy, providing for extra units to take over in the event of failure (or offline maintenance) of the main units.
- ISLANDED MODE WITH UTILITY BACKUP
The system can be designed in islanded mode with utility backup, which enables the plant to operate independently of the utility under normal conditions, with utility backup in the event of a catastrophic failure of the on-site plant. The most reliable system available, it may be appropriate for certain high-level research institutions.
Cogeneration coast to coast
Colleges and universities from coast to coast are asserting their energy independence through implementation of cogeneration. The University of California at San Diego (UCSD) used a contracting firm to construct a design-build cogeneration facility.
The gas-turbine simple-cycle plant configuration incorporates two solar 130S gas turbines with two heat-recovery steam generators. The plant furnishes 25 MW and 203 million Btu/hr at a net plant efficiency of 73 percent. The plant incorporates new emission-control technology, maintaining 2.5 ppmv NOx, 90 percent CO reduction and 90 percent VOC reduction. The plant also has been designed acoustically to produce less than 65 dba sound. The balance of the plant includes a gas-compressor facility, paralleling switchgear, cooling water systems, boiler feedwater pumping systems and process-control systems.
The project required extensive retrofit of the central plant electrical and data systems. The emergency power plant was reconfigured to provide “blackstart” capability, which will allow UCSD to operate under island mode in the event of a utility blackout. The control system integrates an existing electrical metering system and HVAC controls with the new cogeneration plant process controls.
Because technology alone is not enough to manage utility costs, UCSD employs an integrated control strategy, including demand shedding and import-export regulation based on trends in the electrical market.
The final design was completed under a fast-track schedule in five months. The plant went online in the summer of 2001.