IEA ISGAN Annex 6: Discussion paper "micro vs MEGA: trends influencing the development of the power system" (2020)

Whole-system coordination between micro and MEGA, together with cooperation between different system levels, are needed to provide the most value of investments. The microgrid concept could provide a large range of economic, technical and social benefits to different stakeholders. However, depending on opted configuration and operation schemes for a microgrid, conflicting interests might arise. An optimal mix between micro and MEGA approaches should be considered to identify  investment strategies that provide:

• the most socio-economic welfare, with decisions based on overall system optimisation
• increased reliability of the electricity supply
• optimal use of resources in a way to harness maximum utilization and integration of renewable sources and to minimize impact on the environment.

Renewable Energy Sources (RES), mainly as power electronic interfaced generation, play an increasingly important role in the power system. It is likely that RES will be the main source of electricity in the future, and power systems will need to evolve to meet this development. Significant investments are required in both the micro and the MEGA levels to allow the full utilisation and harvesting of available renewable resources.

In the conclusion of this report, main messages are provided in the areas of technology, market, and policy development, as highlighted by the various national directions regarding nuclear power. Finally, reliability levels and criteria used today for operating and planning the power system may not be the optimal for the future power system.

Considering diversified solutions for reliability and security of supply may lead to alternative decisions resulting in other directions in the development of the power system.