In brief, the purpose of the project is to draw up a coherent plan for power system control towards 2025. This involves interdisciplinary collaboration and consensus concerning the underlying principles, both internally in Energinet.dk and among external partners in the Danish electricity supply sector, among power generators, the industry and politicians. International developments are also being monitored with a view to ensuring that standards and products are prepared for the power system of the future. For this purpose, coordination with Danish energy research and development along the way is also called for.

Main conclusions
So far the project results are divided into focus areas for integrating 50% RE into the Danish power system and derived technical issues incidental to maintaining the high level of security of supply.

As regards the efficient integration of RE production into the power system, three main fields are emerging as focus areas if we are to avoid having to build new power stations to meet demand when the wind is not blowing.

The most important focus areas are:

• Activating consumption both in markets and as automatic reserves (more consumption must be activated in the markets when the price is low, not necessarily at night).
• Standardising communication and control of consumption and generation (necessary to ensure open and equal access to market players).
• Utilising the distribution network through the efficient use of local power generation and consumption (active consumption -> local congestion -> preventing optimum demand-response).
• The derived technical issues which must be handled through a combination of market adjustments and new technical requirements as regards both power generation units and certain types of power consumption.

The most important technical challenges are:

• Frequency stability with more inverter-based power generation (wind turbines, photovoltaic cells, fuel cells, batteries etc.) and with more automatic demand-response.
• Short-circuit capacity with fewer large power stations and more inverter-based power generation.
• Voltage, with even greater variation in power transmission (especially in the distribution network from exporting solar power during the day to importing power for electric cars and heat pumps at night).

The focus on electric cars and heat pumps with heat storage in particular makes it possible to realise the political ambitions of reducing CO2 emissions from non-ETS sectors, while at the same time paving the way for the improved national utilisation of RE-based power generation. However, activating these consumption units will contribute to changing consumption patterns in the local distribution networks.

While activating consumption is already technically feasible and possible in the market, it is not sufficiently widely used to meet future demands for integrating RE into the power system. Energinet.dk has, for several years, been working on and supporting the development of solutions which will contribute to standardising communication and the utilisation of the distribution networks, for example under the Cell Project, NextGen, FlexCom, Edison etc.