If you want to delete a turbine, you need to go to the “Turbines” submenu. Here you select the turbine that you want to delete, then you click on the button next to “Delete selected turbine(s)”. After that, you need to confirm that you are sure to delete the turbine. When you are, click on the “Check” button. It is also possible to delete a turbine in the left view by clicking on it and choosing the “Delete” option in the menu.