HOT|COOL NO. 4/2021 - "Going Greener"

District heating plant saves money and CO 2 with Thermal Drone Survey

More than 70 defects were mended in 40 kilometers of underground steel pipes located by drones equipped with thermal sensors to allow asset management programs to work more efficiently on reducing heat loss and CO 2 .

By Marianne A. O. Andersen, Senior PR Advisor, CSRPR

Before the thermal drone survey revealed the full condition of our steel pipe network, we lost up to 12-14 cubic meters of hot water in the grid every day. Now, this loss is only two to four cubic meters. In other words, we avoid heating enough water to fill 66 steam- ing bathtubs – every day. This reduction saves us around £1500 a month. That is a lot of money for a small district heating company like us. At the same time, we have reduced our CO 2 emissions by 10 [metric] tons a year. More importantly, it allows us to preserve and extend the lifetime of our network, maintaining its value to the community.”

These words are by Derek Leask, Executive Director of Shetland Heat Energy & Power Ltd.

The district heating company provides heating and hot water to over 1200 homes and businesses - in a cool climate with an average high summer temperature of only 11.5°C. He continues, “The resilience and longevity of the district heating pipe network in Lerwick were dramatically improved by achieving full visibility of our entire network. We are proud that we now save energy, CO 2 , and money at the same time.” Thermal mapping reveals weaknesses In January, Shetland Heat Energy & Power Ltd. used new technol- ogy to conduct a complete thermographic drone survey of their pipe network. The drone flew at night and used a thermal sensor to measure electromagnetic radiation at ground level. The result- ing data were processed and analyzed to create an ortho map of the whole network. It reveals places where the ground temperature was higher than average. Warm spots are shown as light dots on a purple map. Software specially developed in cooperation with district heating companies compares the map to the grid of pipes in the ground. This reveals irregularities like leaks, wet insulation, hot spots that need further investigations, or poorly insulated valves. A few nights’ silent flying produced a precise map showing the entire network layout with every bit of defect pinpointed. From this, a priority list was compiled, and over 70 interventions were carried out as part of the summer maintenance and renovation campaign, dramatically improving the grid condition. Thanks to expertise from

28 HOTCOOL no.4 2021

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