In a new era of disaster planning, distributed energy can save lives when the grid fails.
The importance of disaster planning has risen dramatically since the Northeast Blackout of 2003 and hurricanes Katrina and Rita in 2005. Distributed energy has also seen a dramatic rise—as an advantage over traditional backup systems that failed under the stress of long-term grid outages, and moreover, these systems are providing energy cost savings, plus lower emissions at these facilities.
When disasters hit, the Federal Emergency Management Agency (FEMA) is often first on the scene, but rather than arrive after the fact, the agency is establishing emergency centers to protect people during disasters, and relying on distributed energy to supply power. Community colleges are proving to be ideal locations for these centers, and applications range from small 125-kW standby power, on up to 4.5-MW-and-larger.
Power solutions can be simple, or complex. A 125-kW diesel generator was the ideal solution for the Maple Woods Campus Center at Metropolitan Community College in Kansas City, MO. Aside from tornados, the area has a history of seismic activity, so the 14,389–square foot facility functions as one of six such locations on various Met campuses throughout Kansas City. A FEMA grant paid for 75% of the program’s $10.8-million budget.
Planning for backup power on a campus brings some unique demands, according to Greg Fendler, P.E., electrical project manager and a principal at the engineering firm of Lankford + Associates, in Kansas City. “Designing and monitoring of the controls was critical because each campus has a mass notification system, and they’re all tied into a central system,” says Fendler. “So the controls within each generator and the transfer switches had to be tied into the same system.”
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Photo: Mark Carriveau
CHP power plants, Elgin Community College |
Another component that had to be considered was the event of terrorism on a campus. “What happens if a building has a terrorist attack and loses power?” asks Fendler. “We had to consider a programmable sequence where certain doors remained locked but others were opened.” Fendler and his team designed the system so the generators would initiate a sequence in the building management system and also restart certain pieces of equipment in a set order. In effect, the generator was something of a linchpin that started the sequence to bring the building back to life after a disaster.
Beyond the control issues, Fendler broke new ground because Maple Woods was the site of the first US generator set certified per the International Building Code (a set of regulations designed for engineers that specify generating equipment and supervise its installation). Actually, the generator isn’t at ground level. Although the building’s centralized location made it ideal for FEMA’s requirement for accessibility within a 5-minute walk from anywhere on campus, the structure was designed to be aesthetically pleasing from all four sides, making the surrounding grounds less than ideal as a reasonable site for generator.
Mounting the Cummins Power Generation DGDK 125-kW diesel standby generator set on the roof solved the problem, but not without complications. “We suffered a lot of delays because the city was worried about the risk of the generator falling through the roof during an earthquake,” recalls Jeff Allen, director of facilities.
Allen notes that fueling the 336–gallon, dual-wall sub base fuel tank is another complication, because the surrounding grounds don’t support anything larger than a typical pickup truck. Fuel must be offloaded from large tankers and driven across the campus in tanks in the back of a smaller truck. Nonetheless, Meyer is happy with the unit’s performance, though to date it runs only during weekly 15-minute status tests.
Operations could become more frequent as the system enters its first season of summer. Fendler notes that his company integrated a building and management system that would expand the generator’s capabilities. “These campuses can use onsite power generation to limit their peak power consumption from the utility,” says Fendler. “They haven’t done it yet, but mainly it’s because the system was ramped up around fall of 2008, and we still haven’t seen the peak summer demand.”
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Photo: Burns & McDonnell
Dell Children’s CHP heat distribution with chilled water storage tank |
Expensive peak demand utility rates were a year-round problem for Elgin Community College in Elgin, IL, a northwestern suburb of Chicago. According to Paul Dawson, managing director of facilities at Elgin, the college averaged a $36,000-per-month peak use fee from Commonwealth Edison. “And that was on top of our consumption bill,” recalls Dawson. “Our CHP [combined heat and power] plant eliminated peak use fees and we saved over $400,000 per year.”
The savings began in 1996, with a new CHP plant on campus. In the first phase involved four, 800-kW Waukesha lean burn natural gas electricity generators. Heat for steam is extracted by four, Beaird Heat Recovery units that produce 2,800 pounds per hour of 15-psig steam per engine. A York, single-stage, 500-ton absorption chiller supplies chilled water, and additional hot water comes from three Kewaunee hot water boilers.
The system’s operational parameters and size have changed since it was installed. But at launch, it was a load-following design that operated during Edison’s on-peak energy period from 9 a.m. to 10 p.m. With the savings calculated at $440,000 per year, Elgin expected a payback on its $2.5 million investment within 6.5 years. Surprisingly, it happened in 5.7 years. Not a bad financial track record, and the performance made for a persuasive argument to expand the system. But Dawson says it’s more than just a monetary issue.
“It’s also about reliability,” explains Dawson. “We now have almost 200 personal computers on this campus. If you just consider how long it takes to reboot, it is probably 10 minutes. Multiply that by 2,000, and there are 20,000 minutes of lost productivity from a power outage, plus the time for recovery of lost data.”
In 2001, a $41-million referendum made money available to upgrade the CHP system, and a fifth generator came online in 2003. Dawson wanted to be in a situation where he had enough engines, so, should one go down, he wouldn’t have to buy outside electricity. In summer months, the base load of the campus surges to 2.7 MW, more than the 2.4–MW system could generate. Moreover, Dawson didn’t like the risk of maintenance or repair time reducing his capacity to three engines. That would leave him no alternative but to buy from Edison. “There is also the risk of overloading the system if you can’t lower the demand quick enough,” says Dawson. “So we wanted to have enough capacity even if we’re down one engine.”
The additional capacity allows Dawson to supply all of the campus with power from the CHP system, and that includes functioning as a FEMA center. The college is the ideal location for FEMA, with ample space and facilities such as showers and seven kitchens on the campus. Barring a disruption of the natural gas supply, electricity, and heat will stay on through a disaster.
Deregulation of electricity ended the peak energy burden on Elgin, but price fluctuations still influence the economics of running the CHP system. Today, Dawson uses a software program to track his cost to make an electricity, and a has yearly contract with an electric power broker for a 2.6-MW block of power during the hours of 9 a.m. to 6 p.m. “The program checks daily on the hourly price of electricity and the difference can be 10 times as much from high to low,” explains Dawson. “This program tells us when to run the engines, and another program calculates gas and maintenance costs to determine the savings or difference in price of steam from the cogen engines rather than the boilers.”
Recently, with the price of natural gas falling, the price of electricity has followed, and Dawson doesn’t need to run the engines as much. “Our goal is to buy natural gas at the lowest point, and if I determine that I can make electricity cheaper than what I’m buying it for I will.” If Dawson’s broker can sell Elgin’s excess electricity at a higher rate on the market, they refund the difference between the higher price and Elgin’s purchase price. Dawson considers the CHP plant’s performance as a success in economics and reliability, and plans on adding another generator to satisfy the college’s future expansion of 200,000 square feet.
The college also views the system as successful in fulfilling its role as an environmentally responsible institution. Overall emissions were 4,106 per year, a figure that amounts to just 11% of the institution’s allowable maximum of 35.93 tons.
Environmental benefits figured strongly in design of Dell Children’s Medical Center of Central Texas. In fact, the US Green Building Council awarded Dell Children’s an official designation as the world's first LEED Platinum hospital. The LEED (Leadership in Energy and Environment Design) rating system has become an internationally recognized benchmark of high-performance green buildings. To achieve LEED certification, sustainable green buildings are rated in five areas: sustainable site development, water savings, energy efficiency, materials selection, and indoor environmental quality.
Obviously, the hospital excels in all of these areas, but according to Ed Mardiat, DBIA, principal at Kansas City, MO-based Burns & McDonnell, a design, procurement, and construction engineering company, Dell’s unique CHP plant (with efficiency ratings of 70–80%) tipped the scales in favor of a platinum rating, rather than the second-highest rating of gold. But this CHP plant is more than just a prime example of green efficiency, it’s also an example of a new generation of distributed energy projects designed to survive disasters and keep critical institutions safe from utility problems.
A look at the lineage of this system provides plenty of reasons for the power plant’s success. Burns & McDonnell based the design on lessons learned from a 2005 prototype project for the Department of Energy and Oak Ridge National Laboratory, to develop a packaged cooling heating and power system at the Domain Technology Business Park in Austin, TX. The project documented efficiency ratings of greater than 80% with the use of a Centaur 50, 4.3–MW natural gas combustion turbine made by Solar Turbines Incorporated, San Diego, CA, and a Broad Air Conditioning 2500 heat recover two-stage absorption chiller. Recorded emissions without catalyst were 9-ppm nitrogen oxide and received the EPA Energy Star Recognition. Using a modular design approach allowed for fast construction times of less than nine months, and less than three months for installation of the CHP modules from startup to commissioning.
Dell’s CHP plant continues the modular design philosophy. The power plant in this setting is Solar’s 4.6-MW Mercury 50 recuperated gas turbine generator. The turbine exceeds requirements of the Texas Commission on Environmental Quality and City of Austin’s green Building Standards. It provides 100% of the electricity requirements of the hospital and related offices, plus absorption, and electric chillers. Heat recovery equipment produces process steam, with a backup boiler for redundancy, plus a chilled water storage tank for off-peak production.
Austin Energy is the local utility that owns and operates the plant, and Dell has long-term contracts for the purchase of power, chilled water, and steam. Although Austin can’t discount the price of power because utilities are still under regulation in Texas, Dell benefits from lower costs for steam heat, plus hot and cold water, thanks to the high efficiency of the CHP system. Then too, the hospital saved $7 million by choosing not to build or operate its own plant, and the modular design kept construction to 12 months, and will accommodate expansion for future growth from a planned “urban campus” on the site that is part of a brown field redevelopment.
According to Mardiat, hospitals are consuming more energy and prefer to have an energy partner finance, design, build, own, and operate their power plants, so they can focus on healthcare service. Moreover, they expect their partners to deliver high-quality power that can provide security from major disasters. But also minor disasters that can disrupt their data center operations. The healthcare industry has forgone paper records in favor of digital record keeping, so clean reliable power has become a critical factor in day-to-day operations.
In fact, the Veterans Administration has mandated that all of their hospitals must have enough onsite power to run in “island mode” (disconnected from the grid) and supply full operations for up to four days (See www1.va.gov/vhapublications/ViewPublication.asp?pub_ID=1379). Additionally, those in disaster areas such as flooding, earthquake, or hurricane zones must have capacity to operate for seven days.
Under normal circumstances, Dell’s CHP plant runs parallel with the local grid, and can use the grid for backup, but it’s ready to switch to island mode at a moment’s notice. “Nearly all hospitals are fed from two independent grid feeds,” explains Mardiat. “Dell’s system is monitoring those feeds so, in the event of a disruption, a voltage stag, or brownout for any abnormal situation, the plant will automatically switch to island mode. The hospital’s operations won’t be affected, because this transition is seamless. Once the problem is identified and cleared, operators can synchronize back up with the grid.” Before the hospital opened, the plant was in its final stages of commissioning, in mid 2008, and there was a brownout situation in Austin—the plant reacted by disconnecting from the grid and continued to run in island mode.
Ultimately, the Dell Children’s Medical Center is a state-of-the-art application of distributed energy benefits, but it’s not that far removed from simpler disaster power sources such as the single generator at Maple Woods. These systems are efficient, reliable, expandable, economical, and, as Dell has demonstrated, capable of achieving a Platinum LEED rating. Now with the growing demand for island mode operations, such as those of the Veterans Administration, more such installations to answer the need for reliable power during disasters are sure to come.