Power systems around the world are faced with a wide range of challenges in order to realize the objective to integrate an increased amount of renewable energy sources in the modern electricity grids. The consequences affect the daily operation and longterm planning of transmission and distribution systems, and the network owners and operator’s ability to ensure continuous, reliable and high quality of supply to the customers. The needs of each actor within the electrical supply chain provide drivers for revision of current practices and promotes future adaptions of functional components and systems, economic and regulatory areas.
This document provides insights in the work of ISGAN Annex 6, in form of key messages consolidated from the views of the focus areas

• Technology Trends and Deployment
• Expansion Planning and Market Analysis
• System Operation and Security
• Transmission and Distribution System Interaction

micro and MEGA represent two trends which largely influence the decisions and the evolutionary process of power grids.

The trends are both aimed at enabling very high penetration of renewable energy sources
in the electric power system, from two perspectives:

• micro focuses on local solutions, while
• MEGA focuses on system or even intra-system wide solutions

ISGAN Annex 6 has dedicated an activity to study the micro and the MEGA trends, with the objective to present a critical assessment of these trends, based on the questions:

• Does one trend outcompete the other?
• Does increased investments from one perspective increase the need for investments
  from the other perspective?
• To what extent can one perspective benefit from the other perspective?

The intention is not to proclaim one solution being superior to another, rather to provide well
informed insights to the needs of considering both perspectives during the planning
and decision-making process for the sustainable development of the wider energy
system.

The outcome of this activity are communicated through publications, presentations and workshops, with contributions from a large number of parties:

• In the Policy Brief: micro vs MEGA – trends in power system development, the condensed knowledge from this activity was published for the 11th Clean Energy Ministerial hosted by Saudi Arabia, September 2020

• In the Discussion Paper (DOI: 10.13140/RG.2.2.11569.61287), the full report is provided from this activity, including detailed insights into the micro & MEGA trends and their perspectives together with experiences from around the World.

• Workshop and meeting in Montreux
  A highly successful event, gathering a total of 30 participants, with presentations (available here) from Italy, India, Spain, Belgium, France, Germany, Norway and Sweden.
  The participants at these two meeting days have shown a high level of engagement and it has been highly valuable to learn from each other. In short, we can conclude that these meetings were very productive and successful in gathering a large amount of knowledge.

In Europe, there is a sharp increase in reserve needs for coping with the variability introduced by a steadily increasing RES share in the generation. The big challenge is to extend the possibility of providing Ancillary Services (AS) – frequency and voltage control, congestion management, etc.) to entities connected to the distribution network.
All these issues have been addressed by the SmartNet European research project (http://smartnetproject.eu/), which aimed at comparing different TSO-DSO interaction schemes and different real-time market architectures with the goal of finding out which would deliver the best compromise between costs and benefits for the system. The objective of this three-and-ahalf year project (2016-2019) was to develop an ad hoc simulation platform which models all three layers (physical network, market and ICT), analysing three national cases (Italy, Denmark, Spain).

In addition to providing information on the main results obtained by the SmartNet project, this report include some information on the status quo of the procurement of ancillary services in selected countries. A questionnaire was formulated and distributed among the members of ISGAN Annex VI. The questionnaire contained the following questions:

• What system services are provided in your country (voltage regulation, frequency regulation, inertia, support to power quality…)
• Who is providing them (generators and/or loads?)
• Modalities to collect ancillary services: via markets, contracts, compulsory non-paid services… Please describe in detail.
• Are generators and/or loads located in distribution admitted to provide system services? If yes, how is TSO-DSO interaction carried out (please describe in detail)
• Are there plans from the national regulator to activate demand side management or to collect inputs from generators connected to distribution for the future? Which timeframe? Are pilot projects already active?

Solutions providing advances in flexibility are of utmost importance for the future power system.
However, flexibility is not a unified term and is lacking a commonly accepted definition. The flexibility term is used as an umbrella covering various needs and aspects in the power system which complicates the discussion on flexibility and craves for differentiation to enhance clarity.

ISGAN Annex 6 has dedicated an activity on flexibility with the intention to support an increased understanding of the flexibility concept, proposing categorisation of flexibility needs in the power system.

This activity resulted in several publications with contributions from parties in: Sweden, Austria, Canada, France, Germany, Italy, Norway, and Switzerland.

• The final results and conclusions of this activity were presented at a dedicated ISGAN Webinar, November 2019.

• In the Fact Sheet: Grid Evolved – Power System Flexibility, the condensed knowledge from this activity, with collaboration with Mission Innovation, was published for the 10th Clean Energy Ministerial in Vancouver, Canada, May 2019.

• In the Discussion Paper (DOI: 10.13140/RG.2.2.22580.71047), the full report is provided from this activity, including description of the flexibility categories: Flexibility for Power, Flexibility for Energy, Flexibility for Transfer Capacity, and Flexibility for Voltage.

• The Leaflet: Power system flexibility – the ability to manage change presents an executive summary of the discussion paper, giving a good insight into the work. This leaflet was published for the ISGAN Conference The future of electricity markets in a low carbon economy in Stockholm, Sweden April 2019.

• The Scientific paper: Flexibility to support the future power systems, based on the discussion paper, was published for the CIGRE Symposium in Aalborg, Denmark, June 2019.

The main objective of this report is to assess the future data exchange and ICT requirements concerning the interaction of distribution and transmission networks, by identifying key challenges that deserve attention.

This report is based on a questionnaire regarding the ICT aspects of TSO-DSO interaction. The questionnaire contained questions regarding technical aspects (e.g. technical connection points between TSO and DSO in the countries), regulatory aspects, flexibility markets, drivers and barriers for TSO-DSO interaction as well as experiences from projects and lessons learned. The questionnaire was sent to the Annex partners and nine responses were collected. In particular Belgium, Germany, Italy, Finland, Sweden, United States, China, India and Austria have sent comprehensive answers.

Due to the integration of renewable energy sources, the interaction between TSOs and DSOs gets more and more important to handle the high volatility of generation and unexpected load growth in power grids. Additionally, new market mechanisms and the connected flexibilities require a closer interaction between TSOs and DSOs.

System efficiency is a multifaceted concept, which in the present document is broken down in the dimensions of carbon dioxide (CO2) emissions, energy and economic efficiency.
In order to improve the efficiency of a given system there are a number of available solutions at the disposal of policymakers and market actors. In this work, five action areas have been chosen and defined – multi-energy systems, electric storage, electric mobility, demand side management and automation & sensor technologies – and a review of activities and initiatives currently underway in several countries has been presented.
The efficiency measures and indicators identified in this report are key for bringing about the vision of an environmentally friendly and economically profitable electrical energy system, although some alternatives are not yet at a stage where they could be readily deployed in a systematic or widespread manner. In these cases and depending on the specific circumstances, regulatory policies and support measures can provide guidance and sustenance to overcome the uncertainties of future developments and promote potentially promising solutions.

In this work, the concept of a single marketplace for flexibility is introduced. Based on the requirements for TSO-DSO interaction, the concept of a single marketplace for flexibility has been assessed. This assessment does not provide a comparison with other ways to ensure a coordinated use of flexibility, but it shows the strengths and weaknesses of a single marketplace for flexibility.

The single marketplace is a lean and transparent concept to deal with the procurement of flexibility, which could theoretically lead to an economical optimum for the entire system, while respecting technical boundary conditions. On the other hand, the marketplace will not function properly without sufficient flexibility offers, there is no practical experience with this concept and the ICT requirements for its implementation are challenging.

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.

A synchrophasor is a time-synchronized measurement of a quantity described by a phasor. Like a vector, a phasor is a complex number that represents both the magnitude and phase angle of voltage and current sinusoidal waveforms at a specific point in time. Devices called phasor measurement units (PMU) measure voltage and current, and with these measurements, calculate parameters such as frequency, real power (MW), reactive power (MVAR) and phase angle. Data reporting rates for these parameters are typically 30 to 60 records per second, and may be higher. In contrast, current supervisory control and data acquisition (SCADA) systems typically report data every four to six seconds – over a hundred times slower than PMUs.

Measurements taken by PMUs in different locations on the network are accurately synchronized with each other and can be time-aligned, allowing the relative phase angles between different points in the system to be determined as directly measured quantities. Synchrophasor measurements can thus be combined to provide a precise and comprehensive “view” of an entire interconnection, allowing unprecedented visibility into system conditions.

The number of PMUs installed worldwide, as well as the number and type of grid operations informed by PMU data and applications, have seen notable increases in recent years. The past six years have seen a significant increase in the number of PMUs installed across North America’s transmission grid, from fewer than 500 installed in 2009 to nearly 2,000 today. This rapid increase in deployment of PMUs was spurred by the 2009 American Recovery and Reinvestment Act (ARRA), which funded federal Smart Grid Investment Grants (SGIG) and Smart Grid Demonstration Projects (SGDP), with matching private funds. In Norway, responsibility for the deployment of PMUs has recently been assumed by the Transmission System Operator’s IT division, meaning that PMUs are becoming an integral part of the grid information infrastructure for system operations.

Higher flexibility in network dispatching can be achieved either by increasing the deployment of bulk storage in the transmission network, or by widening the set of resources available as a base for energy balancing. The latter strategy could potentially be actuated by allowing reserve procurement across transmission operator jurisdictions.

In a European context this strategy would be referred to as trans-national balancing; and could also be relevant to procurement across different Regions and Balancing Authorities in North America. A further positive could be achieved through participation in the balancing mechanism from generators and loads located in distribution networks. Beyond supporting dispatching efficiency, these flexibility elements make it possible to deploy a sustainable expansion strategy of the trans-national transmission corridors, taking into account the current difficulties faced in achieving public consensus for the building of new overhead lines. This report illustrates the potential of these strategies by referencing the results achieved in a number of important and ongoing European research projects.

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.

Changing patterns of demand that new types of load such as electric vehicles (EV) will introduce large and unpredictable fluctuations in the power balance as well as variations in voltage can jeopardize the quality and availability of power. The T&D system has to be stronger and smarter to provide the real-time flexibility needed to efficiently handle the new conditions. Investment needs in the power T&D infrastructure are large and require long term planning and deployment. The environmental concerns and public acceptance issues that often arise when constructing additional conventional transmission lines will require more efficient solutions with lower environmental impact.

This Discussion Paper from ISGAN Annex 6 Power Transmission & Distribution Systems Task 3 and 4 focuses on “Smarter & Stronger Power Transmission” and is a review of feasible technologies for enhanced transmission capacity and flexibility in terms of status and deployment. This includes both the primary AC and DC technology for the high voltage transmission grid as well as the information and communication technology (ICT) required to efficiently supervise and operate the power system. Focus is on the development of power electronics including flexible AC transmission (FACTS) and high voltage DC (HVDC), the standardization within ICT such as IEC 61850 and Common Information Model (CIM) in order to obtain vendor independent interoperability as well as the progress of wide area monitoring, protection and control (WAMPAC). The combination of smarter ICT applications together with power electronics such as FACTS and HVDC can be described as a digitalization of the power system operation offering the required flexibility. Most of the examples given are from the Nordic European power system, reflecting the participation of the authors from ISGAN Annex 6 Task 3 and 4, with additional input from North America and selected International case studies.