Major energy plant with in total 6 boilers, which is mitigating from fossil to renewable fuels, partly coal fired and partly biomass. Currently 70% from the power produced is from biomass. Each unit has a capacity of 660MW, which combines to an overall capacity of 3.3GW. The client faced instable throughput followed by unexpected and costly challenges in shutdowns and non-effective offline cleaning. A trial cleaning has been done by Online Cleaning Technologies to clean one boiler as a test project during the full production. The response of the client was after he witnessed the Online Cleaning Technologies of the production line: “Get them back next week to clean all boilers”. This biggest challenge for Online Cleaning Technologies was the size of the installation, over 20m Width and the enormous high temperatures in the area to be cleaned. Going up to 1600 degrees and direct flame radiation.