High Penetration of PV in Local Distribution Grids

The massive deployment of grid-connected PV in recent years has brought PV penetration in the electricity grids to levels where the conventional fit-and-forget approach to interconnecting PV reaches its limits. In many cases, constraints and limitations of existing electricity infrastructure already have evolved to one of the key barriers delaying or impeding the realisation of PV projects.

While until recently grid issues associated with increased PV Penetration levels have been an issue in just a few local markets mainly in Europe, it has since then become a truly global issue - attracting global interest and attendance. In many cases PV has already become a game - changer in the way utilities, transmission as well as distribution system operators plan and operate power system infrastructure. Last but not least the grid integration of High Penetration PV has been identified as key prerequisite for the future development of the world-wide solar industry.

It is clear that resolving these global challenges requires the broad collaboration of experts from different stakeholders involved and the access to global information on experiences and best practises. Consequently, the Photovoltaic Power Systems Programme of the International Energy Agency (IEA-PVPS) has put up grid integration of on top of its research agenda, following its strategic mission "to enhance the international collaborative efforts which facilitate the role of photovoltaic solar energy as a cornerstone in the transition to sustainable energy systems".

Coordinated by Task 14 "High Penetration PV in Electricity Grids" a worldwide group of experts has been working together exchanging expertise and developing innovative solutions addressing technical as well as non-technical challenges for the advanced integration of PV. From its beginning Task 14 has focused on working together with utilities, electricity industry, and leading research to develop the technologies and methods to enable the widespread deployment of distributed PV into the electricity system.

Task 14 addresses integration challenges and technologies on two main levels of the power system, local distribution grids and the overall power transmission system.

The present report specifically covers aspects related to distribution integration, presenting a worldwide selection of best-practice case studies and the latest findings from the working period from 2010 to 2013 within the IEA Task 14 Subtask 2. It enables the reader to deeply understand the fundamental characteristics of the national distribution grids and associated technical issues that are related to high PV penetration in the local power system. including current technical and regulatory interconnection requirements.

Highlighting technically effective and economically efficient solutions for improved distribution grid integration of high levels of PV penetration, the report supports experts from utilities and industry as well as responsible authorities in their business to design, manage and effectively operate power distribution systems with High Penetration PV.