MONITORING & METERING
THE EVER-INCREASING BENEFITS OF OWNING A POWER AND ENERGY LOGGER
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n recent years Power and Energy Loggers (PELs) have become more prominent in the facility manager or site electrician’s arsenal as their many different use cases increase, particularly those concerning energy efficiency and maintaining the economic and reliable performance of the electrical installation. Whether it be for identifying inefficient equipment, which is responsible for 20% of the electrical energy used by the average UK SME, or reporting out of hours electricity use, which accounts for 46% of UK SME electricity consumption, many businesses are already benefitting financially from investing in a PEL. Add to that the PELs ability to identify poor phase loading and balance, which would otherwise result in one or more phases carrying a higher current than the others. This increases losses due to heating and
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reduces the available supply capacity, and at its worst, could lead to a voltage imbalance that negatively affects some of the 3-phase equipment in the same installation. Fortunately, the measurement of voltage and load (current) balance, and therefore the identification of imbalance, is easily achieved using a PEL. A Power and Energy Logger will also monitor and record power factor, with poor (low) power factor reportedly affecting almost 50% of UK businesses resulting
ENERGY MANAGER MAGAZINE • NOVEMBER/DECEMBER 2023
in higher energy bills. Poor power factor also impacts on the reliability of the installation itself and can cause a variety of electrical issues that may result in the early failure of capital equipment. This equipment often gets replaced at great expense without the root cause ever being observed or identified. Poor power factor can also impact heavily on the capacity to add new loads when a business expands. Logging with a PEL to determine maximum demand is rapidly growing due to the complexity of the diversity calculations required, the fact that the figures in the IET On-site guide are out of date, and the large margins for error built into the calculations. In many recent cases logging has revealed an actual maximum current demand significantly lower than that arrived at using the prescribed diversity calculations, and generally with significant implications on cost savings pertaining to expansion work or determining supply suitability. PV / Battery installation surveys are being performed using PELs prior to embarking on a solar PV project, enabling businesses to gain a comprehensive understanding of their electricity usage patterns by measuring consumption throughout the day and night, assessing variations on a daily, weekly, and monthly basis, and identifying seasonal fluctuations due to factors such as lighting, heating and air-conditioning. The data captured by the PEL provides valuable insights into the actual energy consumption patterns, identifying peak demand periods and usage trends. Information that is imperative when sizing battery systems. In addition to these existing uses for Power and Energy Loggers there are a few “modern day” issues that are now being reported, one of which is the increasing numbers of businesses that are having problems with their EV chargers unexpectedly shutting down. This mostly concerns
