Microgrids encompass a wide range of technologies and applications. However, one common thread is the objective to maintain reliable power using multiple power sources. One example of this is an application that Capstone Turbine Corporation developed for a new green data center at Syracuse University in New York State.
An objective for the Green Data Center was to achieve 50% reduction in energy usage compared to traditional data centers. Achieving this goal meant implementing a variety of innovative technologies, including DC distribution, battery storage, and rear door heat exchangers that use chilled water to cool each server rack independent of its neighbors. There is no traditional hot aisle/cold aisle arrangement since the entire room is now cool.
A significant contributor to the energy efficiency improvement is the use of 12 patented Hybrid UPS microturbines from Capstone Turbine Corporation that power the entire facility. Capstone’s Hybrid UPS system is the first to integrate clean-and-green C65 (65 kW) microturbines directly with a dual-conversion UPS to provide power for mission-critical loads. The microturbines can deliver power to the site loads from three independent sources—a connection to the electric utility, the microturbine engines, or a battery storage system. Normally the system is connected to the utility grid. However, the system can also transition to standalone operation when the grid is unavailable and can do so without interruption of power to the site loads. The microturbines are arranged in a dual cord 2N configuration to increase availability and can operate on either natural gas or a propane-air mixture as backup.
The microturbines are part of a combined cooling, heating, and power (CCHP) system to achieve maximum overall efficiency. Two 150-ton Thermax® absorption chillers convert exhaust heat from the microturbines into energy that chills water used to cool the server racks and the entire building. A Cain Industries heat exchanger can be used at the same time as the chiller to produce hot water to heat peripheral areas of the data center and the building next door. The system also employs free cooling when the temperature outside is low. A separate heat exchanger is used to produce chilled water directly from a cooling tower on the roof.
The system was commissioned in 2009 and has provided both high availability as well as energy savings.
Editor’s note: Steve Gillette is Vice President of business development at Capstone Turbine Corporation.