Smart Integration of Electric Vehicles in the Dutch Power System: Designing mechanisms to manage large volumes of electric vehicle recharging demand in a capacity constrained distribution system

Smart Integration of Electric Vehicles in the Dutch Power System: Designing mechanisms to manage large volumes of electric vehicle recharging demand in a capacity constrained distribution system

Van Beek, R.B.

Herder, P.M. (mentor)
De Vries, L.J. (mentor)
Kunneke, R.W. (mentor)
Slootweg, J.G. (mentor)

Technology, Policy and Management

Energy & Industry

Systems Engineering, Policy Analysis & Management

2010-08-19

The introduction of large numbers of Electric Vehicles (EV) poses significant challenges to the power infrastructure. The combination of expected consumer recharging behaviour and the technical characteristics of the EV’s recharging power demand could potentially lead to significant increases in peak demand and cause overloads. Conventional asset management in distribution network planning is to invest in grid reinforcements to accommodate the expected future peak demand. But, this strategy would result in an significant increase in the currently redundant energy capacity during off-peak hours. In addition to such inefficiency, the long lead times and high costs of reinforcements have led DNO Enexis B.V. to search for alternative strategies. One such strategy is to manage EV recharging demand within the grids’ capacity constraints. EV recharging is presumed to be highly time-flexible and may therefore be interruptible, schedulable and potentially susceptible to economic incentives. If coordinated properly, large numbers of EVs could be accommodated without deterioration of service reliability. Our research was aimed to design such a coordination mechanism for this specific purpose. We concluded that any coordination mechanism should include a DNO operated demand control mechanism which interrupts the recharging in response to overloads. For technical and economic efficiency considerations, the interruption of EVs should be selective. Methods by which the individual consumer is selected may be based on technical criteria or economic differentiation such as bids or prices. Real time dynamic pricing methods were judged insufficient in resolving overloads because of concerns about the level of consumer price response and the differences thereof between consumer categories. The different technical characteristics of Plug-in Hybrid Electric Vehicles (PHEV) and Battery Electric Vehicles (BEV) led us to conclude that their related consumers’ level of response to prices may be absent in some cases and will at least be insufficiently reliable. The alternative technical selection methods, although their discriminatory nature is in conflict with current legislation, are considered preferable over economic selection methods. Such methods could provide BEV consumers, which are critically dependent on the grid and may have a recharging necessity, priority over other (PH)EV consumers. Technical selection based interruptions may not require transactions such as compensations in the early phases of EV adoption. As long as grid energy capacities are still readily available and the EV consumer does not necessarily experience any loss of service due to interruptions. Scarcity of energy capacity, however, may occur soon at local level grids and cables. In addition to response to overloads, an ex-ante mechanism which can spread out recharging demand in time should be considered to limit the frequency of DNO induced interruptions as well as to optimize the utilization of the grid in the longer term. We concluded that the current Dutch legislative environment prohibits DNOs from active planning and scheduling of recharging demand on behalf of EV consumers. Although operated with reliability objectives, such activities effectively constitute an energy supply service which, additionally, would be competitive with similar services offered by energy providers. Alternatively, DNOs should consider introducing price incentives by substituting or supplementing the current fixed connection capacity charges with a usage based network charge. Out of the four rate designs considered in this study, static Time of Use pricing was considered to best meet the DNOs cost objectives as well as consumers’ cost and comfort objectives. Concluding, a coordination mechanism consisting of Time-of-Use pricing accompanied by selective interruptions for real time reliability are proposed. Interruptions of recharging should be based on selective methods which differentiate between consumers on technical criteria. Such a method is considered discriminatory and will likely require institutional changes.

electric vehicle
recharging demand
power distribution
congestion
demand side integration

http://resolver.tudelft.nl/uuid:c32602cc-3edd-4f7d-9c6c-bb688890f8b8

Campus only

Student theses

master thesis

(c) 2010 Van Beek, R.B.