1. Frankfurt (Germany), 6-9 June 2011 Jukka Lassila – Finland – Session 6 – Paper 0773 Network Effects of Electric Vehicles Case from Nordic Country LUT Jukka Lassila Juha Haakana Jarmo Partanen Fortum Kari Koivuranta Saara Peltonen

2. Frankfurt (Germany), 6-9 June 2011 Key questions Jukka Lassila – Finland – Session 6 – Paper 0773 Defining of technical (MW) and economical (€) effects in electricity distribution networks -Classification of information used in analysis -Defining of charging curves for electric vehicles -Developing power flow calculation -Defining of marginal cost of the present network +MW +€

3. Frankfurt (Germany), 6-9 June 2011 City Rural area Urban area Case area o Located in Fortum Distribution network, Finland o 20 kV network (6 feeders) from city, urban and rural areas o Peak load on the feeder*: 3.6–8 MW /feeder o Annual energy*: 10–32 GWh /feeder o Number of delivery sites: 390–5200 /feeder o Estimated number of cars: 980–4000 /feeder * Without electric vehicles Jukka Lassila – Finland – Session 6 – Paper 0773 EV information: -Driving distance: 50 km/day per car -Consumption: 0.2 kWh/km -Charging power: 3.6 kW/car

4. Frankfurt (Germany), 6-9 June 2011 Hour Workdays Weekends Number of cars Present load curve of the medium-voltage feeder (peak week of the year, without EVs) Estimation of amount of EVs charged during the day on the feeder Peak power [kW] Mon Tue Wed Thu Fri Sat Sun Evening Day Night Morning

5. Frankfurt (Germany), 6-9 June 2011 Load curves with EVs (100% and 50%) Present load In residential area (urban area) evening and night- hours are the most challenging from the network capacity point of view

6. Frankfurt (Germany), 6-9 June 2011 One-year load curve with EVs (the topmost curve) from the feeder. The bottom curve illustrates the powers without EVs. The curves include the peak powers of each day; the minimum loads of the days are not presented. One-year load curve with EVs

7. Frankfurt (Germany), 6-9 June 2011

8. Reinforcement costs (method of marginal cost) Network value compared with the peak -low-voltage networks 360 €/kW -medium-voltage network 230 €/kW -primary substation level 100 €/kW Power flow Peak power An example of defining required reinforcement investments on the medium voltage feeder 20 kV feeder (Feeder 1) -Present peak load of the day: 5.6 MW -Additional power because of EVs: +2.0 MW - Average marginal cost: 230 €/kW  Estimated need for reinforcement: 230 €/kW x 2000 kW = 460 000 €

9. Frankfurt (Germany), 6-9 June 2011 Summary of the feeder-specific results Total additional load without load control for the case feeders in the MV- network is 10.3 MW. An estimation for reinforcement needs is 2.4 M€. When the reinforcements of the LV-networks and 110/20 kV primary substations are taken into account, the total reinforcement investments will be 7 M€. Replacement value of the case network would increase by 41 % from the present 17 M€ to 24 M€.

10. Frankfurt (Germany), 6-9 June 2011 Optimised charging (red curve) for the feeder. All the energy for EVs can be taken from the network without increasing the present peak power. Optimised charging There is demand for Smart Grid functions to optimise charging of electric vehicles. With successful optimisation reinforcement of 7 M€ could be avoided in this case area.

11. Frankfurt (Germany), 6-9 June 2011 Summary of the study  Intelligent control of charging of EVs is strongly recommended in order to avoid a) unnecessary reinforcement investments and b) an increase in distribution fees paid by the end-customers  Without intelligent control of charging, the load growth can be significant, varying from 20 to 50 % in the case feeders  With intelligent charging (smart grids) most of the reinforcement investment could be avoided or delayed  To understand the network effects of EVs, the present electrotechnical condition of the distribution network has to be studied first, and careful estimation of the penetration schedule has to be made  More efforts have to put for developing charging profiles which consists both normal household consumption load curve and EV charging curve for different purposes Jukka Lassila – Finland – Session 6 – Paper 0773

12. Frankfurt (Germany), 6-9 June 2011 Jukka Lassila – Finland – Session 6 – Paper 0773