Abstract

The Swedish transportation sector needs to undergo major changes in order to achieve the established goals for climate and environment. The largest change is the replacement of fossil-fuelled vehicles to vehicles propelled by renewable energy sources, such as biofuels and electricity. To account for an increase in local electric power consumption, the electric power infrastructure of Sweden needs to adapt through expansion and reconstruction of the electric power grid. However, changes in infrastructure are usually expensive. It is therefore suitable to also examine alternative solutions, which could potentially be more cost efficient. One of these solutions are vehicle-to-grid (V2G), where electric vehicles acts as local electric power control and provides auxiliary services to the electric power grid. This thesis is a case study of a part of a low-voltage electric power grid on Gotland, with the goal of analysing the potential of V2G in the investigated area. The study focused on utilizing V2G for balancing electric power consumption and generation, and for adjusting voltage levels. Simulations of the area were executed in PSS®E for three different cases; one high-load case, low-load case and average-load case. It was found that by utilizing V2G a ramp up of electric power during mornings was delayed by approximately one hour, making the electric power grid potentially more compatible with photovoltaics (PV). However, the overall effects from V2G was fairly low. This outcome can partly be explained by the assumptions made in the report, and also due to some odd behaviour of the system model. 

Abstract

How many Teslas will it take to crash the Los Angeles, California, grid? This thesis conducts a thought experiment to explore whether rapid adoption of electric vehicles (EVs) in Los Angeles will reduce the reliability of electric power in the Los Angeles Department of Water and Power (LADWP) service territory. Federal and state regulations are encouraging the shift to electric transportation in support of policy priorities that include reducing greenhouse gas emissions and reducing dependence on foreign energy sources. However, high market penetration by EVs will change the patterns of electricity use, especially in urban areas. Under some scenarios, EVs could pose a risk to the reliability and resilience of the electric grid serving these areas. To explore this issue, I developed a model that projects the impact of EVs on the peak power load in Los Angeles in 2030 under different scenarios of EV market penetration and constraints on demand for vehicle charging (e.g., time-of-day pricing). I found that even with moderate EV penetration, if vehicle charging is unconstrained, the load placed on the LADWP grid will exceed the established reserve margin in 2030. Only by adopting some form of incentives for EV drivers to shift their power demands from the normal end-of-day charging routine will the LADWP be able to maintain the reliability and resilience of the power grid. http://archive.org/details/hittingtheaccele1094563490 Civilian, Department of Homeland Security Approved for public release; distribution is unlimited.

Abstract

Range anxiety is a relatively new concept which is defined as the fear of running out of power when driving an electric vehicle. To decrease range anxiety you can increase the battery size or decrease the minimum state of charge, the least amount of power that can be left in the battery, or to expand the available fast charging infrastructure. But is that economical feasible or even technically possible in today’s society? In this project we have used a theoretical model for estimating range anxiety and have simulated the average electricity consumption using two different kinds of electric vehicles, to see how often they reach range anxiety according to a specific definition of range anxiety implemented in this model. The simulations were performed for different scenarios in order to evaluate the effect of different parameters on range anxiety. The result that we got were that range anxiety can be decreased with bigger batteries but to get range anxiety just a few times a year you have to use battery sizes which aren’t economical feasible today. Despite the shortcomings of todays electric vehicles there are promising new and future technologies such as better batteries which might help alleviate range anxiety for electric vehicle owner. The conclusion from this study is that in the present fleet of electric vehicles is in need of more charging stations and faster charging to get by the problem with range anxiety and having a chance to compete with gasoline and diesel vehicles.

Abstract

Electric vehicles (EV), both as battery electric vehicles (BEV) and plug-in hybrid electric vehicles (PHEV) have noteworthy potential to reduce global and local CO2 emissions. However, the fully exploitable potential depends on the actual vehicle kilometers travelled (VKT) that can be electrified. For BEV, the limited range excludes long-distance trips from electrification. For PHEV, long-distance trips are not excluded but the shorter electric driving range could reduce the miles electrified. The aim of the present paper is to compare the potential to electrify total VKT of BEV and PHEV. We use real-world driving data from several 780 German conventional passenger cars that are simulated as BEV and PHEV of different ranges. Furthermore, the CO2 emission reduction potential of both technologies and the influence of battery sizes are analyzed, by combining electrified kilometers with CO2 emission factors. We find PHEV to electrify more miles, both individual VKT as well as total VKT of the overall car fleet for given electric range. The difference in fleet electrification potential is maximal for about 30 km electric range. Compared to conventional vehicles both PHEV and BEV can significantly reduce well-to-wheel CO2 emissions when using renewable energies for recharging. The maximal reduction potential per vehicle is larger for PHEV and achieved at smaller range than for BEV.