Evolutions in the grid operation sector will require an ever closer cooperation between Transmission System Operators and Distribution System Operators. The current interaction between TSOs and DSOs has been investigated for six specified grid operation challenges, and possible future ways of cooperation have been identified. Technical aspects as well as policy aspects have been taken into account.
The technical requirements for an evolved interaction between TSOs and DSOs can be met using available technology. However, several non-technical issues and points of discussion have been identified, of which some are related to the regulated environment grid operators are working in.

Energy access constitutes one of the fundamental building blocks for economic growth, as well as social equity, in the modern world. Access to sustainable energy is needed to achieve sustainable development. This paper serves as an input document to the global discussion on how to reach the UN goal of “Sustainable Energy for All”, by sharing case study knowledge in the field. The following topics are considered through the examination of several implemented cases from different parts of the world:

• Analysis of the interaction between centralized grids and microgrids.
• Analysis of stakeholder decision parameters for electrification through extension of the central grid or microgrids; such as distance from grid, economic feasibility and environmental sustainability.
• Analysis of design differences and requirements for microgrids, based on intended purpose and the needs of the end customer.

It has been determined that good planning, appropriate requirements and clear regulations for microgrids limit the risk of stranded assets and enable better business cases for the involved stakeholders.