Höganäs Energi avoids expensive power peaks with new measurement system
Metrum’s adapted measurement system provides early warnings that help Höganäs Energi avoid tariff infractions. At the same time, monitoring is performed of power quality and disturbances in the grid.
“Many of the customers connected to our part of the grid are homeowners,” says Anders Kallin, system manager at Höganäs Energi in charge of measurements. “On cold winter days, when it’s not enough with geothermal and air heat, many people use their immersion heaters for heating, and because everyone does it at the same time, power needs skyrocket.”
To improve knowledge about their power consumption, Höganäs Energi contacted a number of suppliers of measurement equipment. The choice fell to Metrum and in 2009, joint development began of an adapted system for power monitoring.
Höganäs Energi now uses Metrum’s measurement instrument PQ120 for monitoring a number of points of supply. This entails that they measure the total output and energy that is delivered to the grid area. The software provides automatic prognoses of anticipated hourly power values based on minute values from the respective measurement instruments. When the subscribed power tariff is in danger of being exceeded, an alarm is sent via SMS messaging and/or email, and the personnel at Höganäs Energi have the opportunity to take measures.
Costly to exceed tariff
Exceeding the tariff is expensive – Höganäs Energi pays at least SEK 250,000 each time this occurs, which corresponds to an additional power stage of one megawatt. The power peaks generally occur three to four times yearly, depending on the severity of the winter. This means annual savings of nearly SEK 1 million.
“Exceeding the tariff has cost us large sums over the years, but with the help of early warnings, we can now counter the peaks with backup power and other measures,” says Anders Kallin.
Power consumption in the grid is shown on displays next to the lunch room at Höganäs Energi. The visualization is much appreciated and the display has become a natural gathering point for personnel.
Continuous power quality measurement
With the new measurement equipment in place, Höganäs Energi measures its power extraction in real-time while simultaneously monitoring power quality in accordance with applicable directives. This includes among other things, detailed statistics for both consumption and any disturbances. With continuous power quality measurement, it is also possible to determine whether a disturbance is due to something within the grid – such as the result of a faulty connection or a problem at the site of a connected industrial customer – or if the problem is upstream and beyond the utility´s control.
The utilities in Sweden are always responsible for showing that the electricity delivered to customers is of good quality. To further strengthen its capabilities to verify quality, Höganäs Energi has invested in a number of portable Metrum SPQ instruments, which are connected directly to customer sites where problems are being experienced. An initiative for installation of measurement equipment at each substation is also in the works; yet another measure that can help identify problems and limit outages in the grid.
In conclusion, Anders Kallin mentions that besides improved awareness of consumption, installation of the system has been a positive experience for Höganäs Energi.
“Collaboration with Metrum has been very good; they’ve been both sensitive to our needs and very accommodating. During the years the system has been in service, they’ve fine-tuned it and added several smart functions. We now have an excellent finished product that gives us the information we need.”