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The central-plant expansion included the addition of a chiller and the conversion of the primary/secondary pumping loop to an all-variable-speed/primary-only system. Additionally, the university installed two components of ultrahigh-performance HVAC-optimization software: one that continuously gathers information about campus building loads and controls pump and chiller speeds to match central-plant chilled-water supply to real-time demand and another that provides the university's plant managers secure, real-time Web-based monitoring that enables automated measurement and verification, trend-data viewing, and energy-savings tracking. The combination of these software components is expected to ensure optimized HVAC-system performance for the life of the plant.

With the production of only the amount of chilled water required to maintain building comfort, the university's chiller-plant efficiency increased by 47 percent during the first six months of operation. During this time, the plant operated at an average of 0.55 kw per ton, compared with an average of 1.04 kw per ton prior to installation. Additionally, the project was supported by a $14,000 utility rebate. During the first year of operation, the university is expected to save more than 125,000 kwh of electricity and more than 70,000 gal. of water and reduce its carbon footprint by approximately 160,000 lb.

On-site solar-power generation

The Shops at Mission Viejo's solar-roof installation is the largest of any mall operator in the United States.

Photo courtesy of Element Markets, LLC.

The Shops at Mission Viejo in Mission Viejo, Calif., operated by Simon Property Group, is the site of a 20,000-sq-ft solar-roof installation. During its first two months of operation, the 173-kw system created 24,510 kwh, which offset 33,047 lb of CO₂ emissions. The 1,020 panels supply about 5 percent of the 4.2 million kwh the 1,150,591-sq-ft mall consumes annually.

Construction began Dec. 3, 2008, and was completed 20 days later. The project was funded partially through utility incentives, which helped mitigate total project installation cost by improving both project payback and net-present-value financial performance. To pay for the system, Simon Property Group entered into a multiyear power-purchase agreement with the project developer.

Combined heat and power (CHP)

When Shands HealthCare decided to build a cancer center in hurricane-prone Gainesville, Fla., it knew it needed an efficient, reliable, and environmentally friendly energy source to keep the hospital operational in the event of a power disruption. Following the Northeast Blackout of 2003 and hurricanes Katrina and Rita, emergency generators no longer are seen as viable for state-of-the-art digital hospitals. Shands required an on-site energy system that would keep the facility operational for days — not hours — after disaster strikes.

Shands selected the city-owned utility to finance, design, build, own, operate, and maintain an on-site energy center as part of a 50-year contract. The utility determined that a CHP energy system would be more efficient, reliable, and cost-effective than an N+1 emergency backup-generator solution.

The utility selected an international engineering consultant to manage the design and construction of the energy plant. The CHP system consists of a 4.3-Mw gas turbine capable of producing 800 bhp of steam and 2,400 tons of chilled water. Compared with a traditional central power plant, the on-site system produces 95-percent less nitrogen oxide, nearly 100-percent less sulfur dioxide, and 58-percent less CO₂.

CONCLUSION

Our focus increasingly is shifting from simply using energy to managing it. The emergence of smart-grid communications infrastructure and monitoring/control technologies gradually will modify the way we consume and manage energy in our homes, offices, and factories. Just as telecommunications has evolved from basic services, the energy industry will evolve.

This new era of energy-efficiency management promises to be both fascinating and challenging. Over the next several years, with continued legislative and regulatory initiatives, we likely will see greater economic justification for market adoption. There will be more technologies — and more choices — as we look to reduce energy consumption and cost.

For past HPAC Engineering feature articles, visit www.hpac.com.

Peter Armstrong is a strategic-marketing and business-development professional with more than 15 years of experience in the global energy industry. He can be contacted at petersarmstrong@aol.com.

Data courtesy of Pepco Energy Services