The 20 million pounds per year of carbon reductions expected for Erlanger’s new energy plant is equal to:
* Taking more than 4,000 cars off the road
* The carbon output from supplying 3,000 homes with electricity
* The amount of carbon sequestered from 26,000 acres of U.S. forests.
Source: EPA’s Greenhouse Gas Equivalencies Calculator
As Chattanooga's biggest hospital with more than a million square feet of buildings on its main campus and related offices, Erlanger Medical Center spends nearly $6 million a year on electricity and natural gas to heat and cool its downtown facilities and provide power for everything from hot water to air filtration systems and a host of medical equipment and services.
With more than 50 operating rooms on the main campus at Erlanger that require fresh air to be pumped in and filtered 20 to 30 times an hour to avoid any bacterial contamination, Erlanger is one of the city's biggest energy users for both electricity and natural gas.
A new co-generation system expected to go into operation in November should cut those expenses by up to $1.5 million a year and, in the process of saving energy, also generate power in a cleaner manner to reduce carbon emissions and air pollutants in the region.
"One of the biggest projects going on at Erlanger is something most people will never see," Erlanger CEO Kevin Spiegel said in a recent report on the new energy system.
In its nondescript building behind the hospital, Erlanger is installing a $13 million combined heat and power system — half of which is being financed with a $6.75 million grant from the Tennessee Valley Authority. The new combined heat and power (CHP) system is designed to capture and reuse all of the steam generated in the gas-fired power generators to produce electricity for lighting and appliances, hot water for laundry and showers, steam for building heat and chilled water for air conditioning across Erlanger's sprawling campus on East Third Street.
"We hope this can not only save energy and money but be a real showcase to demonstrate the potential of co-generation and distributed energy," said Ben Edgar, president of White Harvest Energy in Chattanooga which worked with Erlanger and TVA to implement the CHP system.
By having its own generation, the new system also will provide another layer of reliability by being able to supply all of the minimum necessary power to keep the hospital operating indefinitely even if the hospital loses power from the grid. Erlanger also has diesel generators for backup power in the event of an emergency.
The new system is expected to be in operation in November in the central energy plant originally erected as an incinerator for hospital wastes. Erlanger abandoned such incineration to limit its air pollution more than a decade ago and is now moving its energy system to a more efficient co-generation model that also will help produce power by generating 20 million fewer pounds of carbon emissions into the air every year.
"What makes this so attractive for us and to TVA is the load profile here," said John Loetscher III, vice president of facilities, engineering and real estate at Erlanger. "We use a tremendous amount of steam for heating and cooling and for hot water, and this will be much more efficient for us."
Loetscher, who joined Erlanger is 2015, said one of his early goals was to update the decades-old energy system to make it more efficient, cleaner and reliable. Co-generation systems can improve the overall energy efficiency of hospitals, but Loetscher said the initial costs of installation proved too high until Erlanger was able to partner with TVA to help fund the new system.
White Harvest Energy, an energy consulting firm, came to Erlanger with the prospect of landing the TVA grant, which the federal utility included in its 2011 consent agreement with EPA and environmental groups as part of $350 million allocated for clean energy projects to generate electricity with less of a carbon footprint and with fewer air emissions.
The project should have a payback of just under four years on Erlanger's $6.25 million investment. Erlanger is taking its share from an existing bank line of credit at a relatively low interest rate.
The project includes four modular natural gas reciprocating engine units sized at two megawatts each that were produced by 2G Energy AG, a German manufacturer of combined heat and power systems for decentralized generation.
"They supplied what we thought was the most complete and comprehensive package that cut down on the construction and complexity of what we are doing here at Erlanger," Edgar said.
The project is the biggest yet in the United State and the fifth biggest in the world for 2G, which has installed more than 5,000 energy systems in 37 countries around the globe.
The company assembled the energy units in Saint Augustine, Florida and shipped the units via truck to Chattanooga in June. The 2G CHP systems reach industry leading total efficiency between 85 and more than 91 percent, or nearly double the efficiency of most electrical generators by utilities which don't recapture all of the steam heat and require more long-distance power transmission.
When in full operation, the new energy plant should reduce enough carbon emissions to equal taking 4,000 cars off the road or planting another 400,000 trees.
Contact Dave Flessner at email@example.com or at 757-6340.