Government Power: Engineers measure circuit-level energy loads using the small battery-powered HOBO data logger UX120-018 for the New York State Government Office
To keep the New York State government running smoothly, its capital offices need a steady, reliable power supply, even during emergencies. When General Services decided to replace emergency backup generators for their offices in Albany, the first challenge was for engineers to accurately assess and measure the power needs of more than 20 buildings.
The complex includes the Capitol, which is a 19th-century Italian Renaissance, Romanesque, and French Renaissance architectural style, as well as several high-rise office buildings ranging in height from 20 to 30 stories. In the event of an emergency cut to the building from the main grid, emergency generators are required to provide sufficient power for lighting and other essential services.
Ryan Thordson Associates is a general office of energy engineers and New York Power, a state-owned electricity provider. He is responsible for assessing emergency energy loads so that the company's multimillion-dollar generators, last year, can be sized correctly. He admits that a lot of riding is getting this right.
Thordson acknowledged that it is possible to rely on electricity to measure the energy use of the entire building, but for this project, the engineers needed more details. The challenge was to measure electricity demand at the individual circuit level, which meant collecting data from 200 points spread across 20 buildings, all over the project's roughly half-year period.
Thordson's experience with energy assessment and recording equipment led him to suggest small, battery-operated portable data loggers for this project. GSO purchased 16 HOBO® Energy Loggers from Onset Multi-Channel Data Logger UX120-018 (U12-018), connecting each to a WattNode® kilowatt-hour transducer with a pulse input adapter cable. Sensors monitor current and voltage, and convert them into pulses proportional to degree, which are then sent to HOBO energy loggers, which record the resultant data.
Energy data loggers, which are wired via sensor circuits in the building's electrical installation switch room, where they take readings every minute, 24 hours a day. Once a week, Thordson downloads the energy data for each circuit to his laptop. When he connects the data logger to the computer via a USB cable, Onset's HOBOware® professional graphing and analysis software recognizes the logger and downloads the week's data points in seconds. He then connects a new circuit to nearby U12-012 or moves to another building.
Thordson likes that energy data loggers are easy to set up and use, which was one of the main reasons he chose them. The software is intuitive and automatically recognizes loggers and sensors when plugged in. , setting up the device does not involve any programming or wiring.
Using the small portable data logger RX3000 is not the way the NYSG could gather energy load information. Thordson explained that they could infect another engineering firm for $200,000 to $250,000. However, by purchasing the UX120-018 and collecting and analyzing them themselves, they will be able to do the research for about $25,000 -- a significant savings.
Another benefit is that the company now owns 16 portable HOBO data loggers UX120-018 and can reuse them in the future. Since each unit has six plug-and-play data input channels, they are flexible and can be used for multiple monitoring needs. The UX120-018's ability to easily adapt third-party sensors, using the optional analog module, is also beneficial, he said, because engineers won't know what data collection needs they'll have.
The unit has been successfully collecting energy usage data for several months, and Thordson expects he will be on target to profile the engineers responsible for delivering the energy sized to the generators.
He also predicts that industries such as granular energy use data will become increasingly important. Building managers and engineers typically rely on the use of power meters, he explained, but the way to have a quality energy management program is to have some sort of on-site metering. Understanding energy loads at the circuit level can translate into significant cost and energy savings.
