Task 14 – High-penetration of PV Systems in Electricity Grids
The APVI has a research project on this Task. For more information on this project go here.
As solar electricity continues to grow its share of the global electricity mix, it becomes increasingly important to understand the technical challenges facing high penetrations of solar electricity, especially the effects of its variability with respect to the reliability and stability of electric power systems. Overcoming the technical challenges will be critical to placing solar electricity on an even playing field with other dispatchable generation resources in an integrated resources planning process and will allow solar electricity to be fully integrated into power system operations – from serving local loads to serving as grid resources for interconnected transmission and generation systems. There is a strong need for international R&D collaboration to address this evolving field and to collate and disseminate worldwide knowledge about high penetration levels of PV.
The main goal of Task 14 is to promote the use of grid-connected PV as an important source in electric power systems at the higher penetration levels that may require additional efforts to integrate dispersed generators. The aim of these efforts is to reduce the technical barriers to achieving high penetration levels of distributed renewable systems.
Task 14 will focus on electricity grid configurations with a high penetration of RES, where PV constitutes the main RES. Although up to now no common definition of “high-penetration PV scenarios” exists, there is consensus amongst the parties developing this Task that a high penetration situation exists if additional efforts will be necessary to integrate the dispersed generators in an optimum manner.
Task 14 will analyse the particular issues related to the penetration of PV in electricity grids and establish penetration scenarios in order to guide discussions on respective technical challenges. Key aspects which influence this definition can include:
- characterization of the load (worst case, average, peak, load shapes, seasonal aspects…)
- AC output characteristics of PV (seasonal, daily, spatia)
- influence of the grid characteristics (e.g. grid topologies, impedances, etc. )
Due to the fact that a number of distribution system integration-related issues are emerging first for PV systems, Task 14 will focus on working with utilities, industry, and other stakeholders to develop the technologies and methods to enable the widespread deployment of distributed, grid-connected PV technologies.
Task 14 aims to:
- develop and verify mainly technical requirements for PV systems and electric power systems to allow for high penetrations of PV systems interconnected with the grid
- discuss the active role of PV systems relating to energy management and system control of electricity grids.
PV systems have some unique features which have to be considered when integrating a large number of such distributed generators into the electric power system. Some characteristics are inherent to the technology (i.e. fluctuating generation, inverter connection) while others are dependent on the current state of the technology, costs and support incentives. Features of particular interest include: fluctuating generation profiles, typical system sizes, connection predominantly at LV and MV grids, inverter connection (no transformer), heavily dependent on support incentives, typically linked to buildings, suited for new decentralized storage solutions and currently limited to few markets / countries.
Large-scale installations are becoming more popular in a number of countries with specific support incentives while in other markets predominantly small-scale systems are installed. However, with changing framework conditions the current mix of small-scale to large installations may change dramatically over the life of this new Task. Similarly, if the expected reduction in PV costs to achieve (close to) grid-parity occurs during the period of this Task, then support incentives will be less important and it is likely that PV will become an increasingly important factor in many markets, rather than just a few.