Study of the potential implication from large scale BEV employment in Swedish households

Abstract

The electrification of society could radically change the electricity consumption of households when loads like Battery Electric Vehicles are introduced. The annual maximum power demand (also referred to as the rated power demand) of a house hold, represents how much electricity a household consumes when it consumes the most in the time-span of one year. This study investigates how the rated power de mand of households changes with a deployment of Battery Electric Vehicles. Data from The Swedish Energy Agency on apartments and villas electricity consump tion was combined with estimated charging profiles for Battery Electric Vehicles, extracted from GPS measurements of 429 vehicles in Western Sweden. Results from this study indicate that the increase in households annual maximum power demand (rated power demand) from the introduction of Battery Electric Ve hicles can vary from a 50 % increase to a 800 % increase, depending on how many Battery Electric Vehicles are charged simultaneously and how many vehicles are connected to the same part of the grid. Limitations of current fuses indicate that load balancing and controlled charging could be a necessity. The result shows a clear linkage between the type of household (villa or apartment), the number of inhabitants and the increase in households rated power demand. In dependent of the number of households included in a combination, Apartments most frequently display a higher increase (250 %) in rated power demand compared to villas (75 %). Current household fuses are not able to cope with this increase in power demand and thus the results implicate the need for load balancing in house holds - distributing the increase over a longer time. For a certain number of inhabitants, the increase can vary in magnitude, this varia tion seems to decrease as the number of inhabitants increases i.e. when aggregating the power demand of more and more households. The maximum possible increase, change less and less as the number of inhabitants increase, which could strengthen the argument that a neighborhood is better suited for a full introduction of Battery Electric Vehicles if only uncontrolled home charging is available. The maximum observed rated power increase with the size of the neighborhood. For a neighbor hood consisting of up to 16 apartments it is 140 kW and for a neighborhood made up of 20 villas it is 150 kW, whereas the corresponding number for a neighborhood consisting of the combination of apartment and villas is 225 kW. The study indicate benefits of controlled charging as there is a possibility to reduce power demand, by strategically charge vehicles at certain periods of time.