Analysis of the impact of controlled charging and vehicle to grid on growth of electric vehicle and photovoltaic systems: a case study in Amsterdam

Abstract

In this research the impact of increasing share of photovoltaics (PV) and electric vehicles (EV) growth on the existing low voltage (LV) grid in Amsterdam is assessed. A model has been created that simulates the impact of the changing electricity supply and demand in a typical neighbourhood in the centre of Amsterdam based on governmental target until 2040. In order to make statements on impact in different kind of areas, an uncertainty analysis has been performed as well. Besides grid performance with existing technology, two new charging technologies are assessed to determine their impact. These are controlled charging (CC), where the charging speed of EVs can be altered, and vehicle to grid (V2G), which has the potential to return electricity from an EV back to the grid. Furthermore, also battery degradation due to CC and V2G services is looked into. The simulations have shown that overdemand will firstly occur in January 2018. From 2021, overdemand also occurs during evening demand peak on weekdays in July. From then overdemand grows every year until EV growth stagnates. Oversupply due to exceeding PV power generation only occurs in periods with high solar intensity, starting in 2031 when installed PV capacity equals 57,5% of fixed electricity demand in the neighbourhood. From then the amount of overcapacity grows with increasing PV capacity. Controlled charging avoids overdemand by slowing down charge speed during peak electricity demand and by charging EVs with PV surplus during midday. Although charge speed is reduced during peak demand, all EVs were able to perform their required trip. CC reduces PV oversupply with two years and increases PV self-consumption in one neighbourhood in 2040 from 42,1% to 50,9%. Vehicle to grid has shown the same results as CC. The main reason is that CC already avoids overdemand, so from the point of view of the electricity grid V2G is not required with CC technology in place. CC reduces the average state of charge of an EV battery, which improves battery performance. Since V2G services are not simulated, the impact on battery degradation could not be found. A short literature study on battery degradation due to V2G services however indicated that despite the lack of consistency on this topic, intensive V2G use could have a notable impact on battery degradation. However, flexible pricing mechanisms and new business cases for EV batteries could turn this into profit for EV owners.