Energiesparrechner Machen Sie den Check! You are here: Private customers service More services Energy saving calculator Save energy Made easy With our energy-saving calculator in cooperation with CO 2 Online, you can check which heating or air conditioning system is the right choice in an environmentally and financially friendly way. Whether subsidies or modernization or energy saving tips - you can find all this in our energy saving calculator. Efficiency is the trend - for the sake of the climate. Customer service Find the right service form here quickly and easily. You are also welcome to log in to the online customer center . There you will see your bills and rates , your payments and deductions . To the services Customer center Ostring 28 44787 Bochum, Germany opening hours Customer center from now on opened again. Whatsapp Live chat Video advice Appointment Our app for iOS Our app for Android data protection Cookie settings imprint We use cookies to provide you with additional services and to analyze calls to our website so that we can continuously improve our offer. By clicking on "OK" you consent to the use of cookies. You can change or revoke your consent at any time via the cookie settings . You can find out more about this in the data protection declaration . OK More info imprint | data protection