Challenges and opportunities in grid connected commercial scale PV and wind farms

Wind power generation and Solar PV installations continues to grow and are the two key contributors to the large scale variable power generation mix. Utility transmission system operators impose stringent grid codes internationally. Grid code regulations are defined by system operators to outline the rights and responsibilities of all the generators and loads that are connected to the transmission/distribution system. In the past, grid codes did not include any regulations for Wind Power Plants (WPPs) and PV plants as the penetration levels were small. However, the situation has now radically changed as many countries have installed many GW worth of variable power generations. The increased reliance on renewable power generation has raised some serious concerns regarding the negative impacts of large WPPs and PV on the stability of power networks. Modern grid codes require WPPS and PVs not only withstand various grid disturbances but also to contribute to network stability support and ancillary services provision, as do conventional generating units. Solar shading can cause PV output to drop by as much as 70% in a space of few seconds. This requires strategies for solar smoothing. In this plenary paper, status review, research challenges and opportunities in developing enabling technologies in grid code compliances, solar smoothing, storage and congestion management to maximise renewable energy penetration into the grid are presented.