The Technical Challenges Facing the Integration of Small-Scale and Large-scale PV Systems into the Grid: A Critical Review

Abstract

Decarbonisation, energy security and expanding energy access are the main driving forces behind the worldwide increasing attention in renewable energy. This paper focuses on the solar photovoltaic (PV) technology because, currently, it has the most attention in the energy sector due to the sharp drop in the solar PV system cost, which was one of the main barriers of PV large-scale deployment. Firstly, this paper extensively reviews the technical challenges, potential technical solutions and the research carried out in integrating high shares of small-scale PV systems into the distribution network of the grid in order to give a clearer picture of the impact since most of the PV systems installations were at small scales and connected into the distribution network. The paper reviews the localised technical challenges, grid stability challenges and technical solutions on integrating large-scale PV systems into the transmission network of the grid. In addition, the current practices for managing the variability of large-scale PV systems by the grid operators are discussed. Finally, this paper concludes by summarising the critical technical aspects facing the integration of the PV system depending on their size into the grid, in which it provides a strong point of reference and a useful framework for the researchers planning to exploit this field further on.

An Investigation into the Potential of Hosting Capacity and the Frequency Stability of a Regional Grid with Increasing Penetration Level of Large-Scale PV Systems

“…(N strings × I sc ) < Max DC input current of inverter (5) The output of the PV system should be equal or closely related to the inverter's rated power. Moreover, in Europe, the inverter's power could be in the following range in respect to the PV generation [22]:…”

“…By 2040, it is predicted that PV technology will become the most dominant contributor in electricity generation among all other sources of renewable energy [4]. However, integrating large-scale PV systems into the grid will bring up a new set of technical and grid stability challenges because of their uncontrollable varying generation output [5].…”

Impacts of Renewable Energy Resources on Effectiveness of Grid-Integrated Systems: Succinct Review of Current Challenges and Potential Solution Strategies

“…The effects that some of these technical challenges would have depend largely on size, since small-scale solar systems tend to be compatible with distribution networks, while their large-scale counterparts are often targeted at transmission grids. For small-scale PV systems in distribution power grids, for instance, it is generally opined that issues of voltage regulation are the most critical technical challenges [222]. Several notable studies that investigated some of these challenges and applied solution strategies are discussed here.…”

Power Quality Assessment of Grid-Connected PV System in Compliance with the Recent Integration Requirements

“…PVPPs have various characteristics that differ from the traditional power plants, which in turn lead to new For power quality, grid codes from countries such as Germany [3], Italy [4], USA [5], Australia [6], and many international standards like IEC standards [7] and IEEE standards [8] have enforced strict power quality rules for PV and other renewable energy sources (RESs) integration. For instance, during voltage sag, which is normally caused by the grid faults, the new requirements necessitate injecting reactive current into the PV system to overcome the sag event and to support the grid stability [9,10]. The limits of voltage fluctuation, harmonics, power factor, voltage unbalance, and flicker have also been defined and imposed.…”