Melissa describes her experience with DC optimizers, where components on the roof start to fail. She had a system where one faulty optimizer shut down the entire string and then the inverter, while the monitoring platform did not show the issue. It can also happen that multiple optimizers fail until a string or the entire systems does not turn on anymore. Her experience underlines the compromised reliability that module level shutdown causes: a significantly increased number of sensitive power electronic components has to be installed on the roof, where they are exposed to extreme temperatures and harsh weather. Since every component has a certain failure rate, as well as a 100% wear rate over time, the reliability of systems is compromised.