As a consumer you have to calculate with increasing energy costs. This calls for an independent energy supply. dach & fach strunz recommends the roof as an energy source: not only electricity but also warm water can be obtained with the installation of photovoltaics and solar thermal energy for self-sufficiency.
With the input in the public power grid, you can secure governmental support. Additional support offer solar credits or the EEG-support, so that the one-time investment of the installation is improving a rate of return and the efficiency of the system, for you to get independent.
An overview of different support measures 2018/ 2019 for photovoltaics and what to consider can be found here: