(Sektorkopplung) Sector coupling refers to the integration of electricity, heating, and mobility in order to increase the share of renewable power used in the latter two, which have so far seen little progress in switching to cleaner energy sources. Sector coupling can also help stabilise the grid by providing → 'storage' (see below) for excess renewable electricity when production surges – for example in car batteries, or in the form of synthetic methane stored in the gas grid (see → power-to-x).
To maximise the efficiency of the power system and to keep the grid stable with a growing share of renewable power – much of it from small, distributed providers – scientists say the power grid needs to respond to real-time information on supply and demand. Smart grid network gadgets include smart meters and appliances that automatically adjust consumption to make use of power when it is abundant (and cheap), and save it when it is scarce (and expensive). In Germany, they are yet to be deployed on a large scale – partly because Germany’s strict data protection laws complicate the collection of data on power consumption.
(Speicher) Because renewable production fluctuates with the weather, it often causes grid congestion and cannot always be relied on (see → re-dispatch costs), while → baseload power from conventional power plants is still used to ensure security of supply. In the future, storing renewable power is predicted to play a more important role in allowing Germany to give up fossil fuels altogether, alongside flexibility options like demand-side management. Some industry players already use battery storage plants to balance short-term fluctuations in power supply and to keep the grid stable (see → grid services), but operators argue that the current design of the power market does not offer sufficient financial incentive for the development of battery plants. Longer term storage would require the availability of much larger volumes of power, which in turn would call for other solutions, for example power to gas conversion (see → power-to-x).