Mixture of energies symbolises system integration of renewable energy; Source: BMWi/Holger Vonderlind

© BMWi/Holger Vonderlind

In future, renewable energy should provide the majority of the energy supply in Germany. By 2050 it is aimed for at least 80 per cent of the power supply to come from renewable sources. Renewable energy must therefore be constantly integrated into the power supply system so that it can progressively replace conventional energy sources. This requires a fundamental change in the energy supply system. Ensuring a reliable, environment-friendly and economically efficient power supply is one of the major challenges of the transformation of energy policies.

The goals of the system integration of renewable energy are especially:

  • Reliable grid operation using a high proportion of renewable energy,
  • Improved flexibility of power generation and power demand,
  • Smart interaction of power generation, consumption and modern grids,
  • Efficient use of the existing grid structure.

New challenges

These goals create new challenges for the general framework conditions of electricity markets and the expansion and modernisation of power grids. The statutory and regulatory conditions must adapt to a constantly changing power supply system and must intelligently influence the transformation process.

At present, the proportion of renewable energy in the electricity supply is about 30 per cent. But this value is merely an average for the whole year. In the course of a year, this proportion already reaches higher levels at peak times. On an hourly basis, the fluctuating proportion created by renewable energy - i. e. wind and photovoltaics - is sometimes more than 60 per cent. According to the grid development plan 2014 (scenario B), in 2024 there will probably be almost 140 GW of installed renewable energy capacity in Germany. But the power consumption (load) within one year will only fluctuate between approx. 40 and 80 GW. This means that in future, renewable energy will increasingly be able to meet or even exceed the current demand for electricity. On the other hand there will also be periods, such as long wind-free times in winter, when not much renewable energy is available. In the foreseeable future, such "dark phases" will still need to be covered by facilities such as flexible conventional power stations to ensure the reliability of the power supply. Eventually, such periods could also be covered by long-term electricity storage.

Important role of power consumers

The energy supply system must adapt to the large temporary variations in the supply and demand situations. In addition to a regional or national compensation for weather-related fluctuations in renewable energy, areas such as power generation must also be better adapted to the demand. On the other hand the consumption of electricity ("load") must also become more flexible, e. g. by load management. In this system, electricity is systematically used when a lot of electricity is available, e. g. when the winds are strong. Variable tariffs can make it possible for such "load shifts" to be financially worthwhile for the end user. Adjustments on the consumer side can also be used to reduce the maximum load, and thus the volume of power needed for a reliable supply. This means that power consumers can also contribute to the reliability of the power supply.

In addition, the largely decentralised renewable-energy installations must increasingly take a share of the responsibility for the overall system and provide the sort of services to ensure the stability of the power supply which have so far especially been provided by central fossil power stations.

Necessary changes in the electricity market design

Renewable energy will be the dominant source of power in the coming years. The rules of the electricity market (the "electricity market design") must therefore be developed to ensure that the electricity market will continue to ensure a reliable, cost-efficient and environment-friendly power supply with a growing proportion of wind and solar power in the future. Against this background, the Federal Ministry for Economic Affairs and Energy has established a new dialogue model in which various structural options are discussed and developed together with the relevant market participants: the Electricity Market Platform.

SINTEG funding programme aims to integrate renewable energy into the grids

The Federal Ministry for Economic Affairs and Energy's new funding programme "Smart Energy Showcases - Digital Agenda for the Energy Transition" (SINTEG) aims to develop in large model regions exemplary solutions for a climate-friendly, secure and efficient energy supply with high proportions of intermittent power generation on the basis of wind and solar energy. The programme focuses on smart grids which should help to ensure stability and improve the interplay of power generation, consumption, storage and grids by means of modern information and communications technologies. You can find out more about SINTEG here.