Grid impact of photovoltaics, electric vehicles and heat pumps on distribution grids — An overview

Distributed generation, such as photovoltaics (PVs), and electrification of heating and transportation with heat pumps (HPs) and electric vehicles (EVs) will play a major role in the energy transition. However, these low-carbon technologies (LCTs) do not come without side effects such as voltage violations, power loss increase, component overloading, higher energy consumption, power peaks, and power quality issues, e.g., harmonics and phase unbalance. This work constitutes a review analysis and summary of all the important findings concerning the various grid impact issues that can appear due to the grid integration of these 3 LCTs. The work also encapsulates various research characteristics such as grid topology, seasons, simultaneous operation under various LCT combinations, penetration levels, etc. Moreover, it incorporates a qualitative analysis of the impact level of the most investigated grid issues and quantitative comparisons between the different grid types and LCTs. It has been shown that the combined integration of PVs-EVs and PVs-HPs can result in mitigation effects without extra solutions. Moreover, voltage deviations and unbalance affect more the rural grids while component overloading is more hazardous for suburban grids. Finally, proposed mitigation solutions, such as energy storage, smart charging, etc., are correlated with their respective grid impact issues. • Rural grids: Most vulnerable to voltage deviations and unbalance due to long distribution lines. • Suburban grids: most vulnerable to component overloading due to high already existing loading. • Unbalance, harmonics, power factors: still not adequately investigated for combined LCT integration. • Combined PV and EV integration: provides grid impact mitigation with less need for extra solutions. • Contradictions in the literature about the grid impact level comparison between PVs, EVs and HPs.