Interplay between EV batteries and power grid - learning from the EDISON project Ningling Rao Innovation Center, Group R&D DONG Energy, Denmark March 21, 2012
Agenda DONG Energy at a glance Challenges and opportunities in renewable energy integration EV batteries: grid congestion threats or flexibility resources? EDISON project The consortium Proof of concept testing The green energy landscape 2
DONG Energy - a leading energy group in Northern Europe We are headquartered in Denmark Our business is based on procuring, producing, distributing and trading in energy and related products in Northern Europe 3
The journey of the Danish energy sector towards a reliable and sustainable energy system in an international market Paradigm changes in the Danish energy system 1970s 1980s 1990s From oil to coal CHP champion Wind power 2000s Liberalization Oil Coal Gas Biomass 2010s Green & flexible Oil fired plants Oil crisis Retrofit for coal State-of-the-art CHP Gas network Climate change starts to gain attention Wind power grows From single turbines to wind farms Interconnectors New market framework Sector on commercial terms Large scale offshore wind World leader in offshore wind High share of green energy Integration via flexibility Smart energy cause changes in the underlying structure of the energy system % % 100 100 100 50 Thermal 50 Thermal 50% 0 0 0 % Wind 4
Danish green energy targets put the energy system under pressure for change Government targets are driving this process which has extensive impact on the energy value chain % Wind penetration relative to demand 21% 2010 50% 2020 Increasing proportion of intermittent power (wind) Production Significant extension of wind and biomass to provide renewable power Heat constrained operation on CHPs cause surplus power production CO2 emission reduction relative to 1990 11% 2010 40% 2020 Transmission Need for increased interconnector capacity and enhancement of the transmission net Pressure to store renewable power within heating, cooling and the gas transmission. Distribution Pressure on distribution net capacity and ability to integrate local PV production and new loads % RE in electricity and heating** 34% 2010 100% 2035 100% Increasing proportion of new loads and local generation Consumption Increase in green" and efficient customer solutions Power based energy consumption Deployment of distributed generation 22% % RE in all sectors 2010 2050 Source: Danish Ministry of Climate, Energy and Building, Group Regulatory Affairs * Note: 11,4% refers to non-adjusted data. If the data is adjusted for the low emissions in 1990 due to large hydro reserve in the Nordics, the reduction is 23,8%. While the Kyoto target refer to non-adjusted data, it remains unclear what the Government target refers to. ** Note: No coal for power production, neither oil burners for heating in 2030 5
VISION Clean and reliable energy
Denmark has been a first mover when it comes to adding intermittent energy to the energy system The extensive build-out of wind turbines has earned Denmark a leading position internationally Potential impact for balancing 15 25% 5.000 ~25%* GW 10 5 20% 15% 10% 5% Wind share* MW 4.000 3.000 2.000 0 0% 1990 1995 2000 2005 2010 Central Decentral Wind Wind share* 1.000 0 * of total power consumption Wind powered energy production Demand load 25 5.000 ~50% Wind share % 20 15 10 5 MW 4.000 3.000 2.000 1.000 0 DK IR DE UK NL SE Onshore Offshore 0 Wind powered energy production Demand load Source: Danish Energy Agency "Energy Statistics 2010", and EEA based on NREAPs 7 Source: DONG Energy S&D *Data from West Denmark, January 2010 (Energinet.dk Markedsdata)
Increasing wind power shares create imbalances in the power system Increasing wind leads to the identification of four distinct problems DK1 in January Wind 2000 Increase Wind 2011 MWh 4000 3500 3000 2500 2000 1500 1000 A B Surplus When wind power exceeds all demand, surplus of wind power has to be utilized. Deficit When wind power falls short in meeting the demand, deficit has to be compensated by back-up sources. Load 2011 500 0 1 11 21 31 Surplus A Days ' C Ramping When the amount of wind power changes rapidly, the power system has to be highly flexible to absorb the fluctuations. Ramping C B Deficit Grid services D Time D Grid services Large share of wind and PV power implies strong need for ancillary services to secure grid stability. 8
The four balancing challenges produce a range of cases A Surplus B Deficit C Ramping D Grid services High wind No wind Wind fluctuation Congestions High winds combined with low demand results in increasing excess capacity Periods with little or no wind will necessitate back-up production thus narrowing base load periods Change in wind speeds and the occurence of e.g. storms necessitate fast regulation of back-up capacity The exisiting distribution grid is risking periods of congestion as loads increase, e.g. by EVs Forced production CHPs are forced to run to produce heat resulting in excess capacity even when the wind is also producing Import limits In dry years and during wind deficits there could be extreme pricing of electricity in the future system Peak loads Unpredictable loads will create needs for fast ramping of CHPs to respond to sudden peak demands Distr. generation Local production from e.g. PV will increase pressure for grid investments 9
EDISON - Electric vehicles in a Distributed and Integrated market using Sustainable energy and Open Networks Key figures Official establishment of consortium was 25 Feb. 2009 Total budget of the project is approximately 6.5M Public funding from FORSKEL (Project No. 10426) program is approx. 4.4M
Electric vehicles in the Distribution Grid: are they grid congestion threats or flexibility resources? The need for intelligence Different charging patterns in peoples homes have different consequence. Uncontrolled charging Alt. 1 Uncontrolled charging during the afternoon peak will create a situation where the capacity of the network has to be almost doubled, compared with the situation today. Alt. 2 Intelligent charging where charging intervals are placed in off-peak hours will open for a situation where the need for network enhancement will be only 35 pct which is more or less in line with already existing plans. Intelligent charging
Smart charging Avoid charging at peak load Charge when there is a surplus of renewable energy! 250 200 150 100 50 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Estimeret el til transportformål Normalt forbrug 10/0,4 kv station What to control? How to control? Who is controlling? What are the costs? What are the benefits? 180 160 140 120 100 80 60 40 20 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Estimeret el til transportformål Normalt forbrug 10/0,4 kv station
Do we need smart charging - case study A SUBURBAN STREET with 50 residences Between 3 and 8 of the households are able to charge an electric vehicle, if this is done unintelligently and in the household activities peak periods. All 50 households (and 30% more) are able charge an electric vehicle, if this is done by smart charging!
EDISON proof of concept tests Test A Test B Test C Test D Test E Batteries Communication Grid impact Fast charging System integration 15
SYSLAB test setup for smart charging and power balancing
Proof of concept test platform
Battery test samples Battery Size Max charge current (A) Max discharge current (A) Quantity NMC pack (12X8S1P) 26.6 kwh 75 Ah / 355 V 225 450 1 NMC module (8S1P) 2.2 kwh 75 Ah / 30 V 225 450 2 LFP pack (10X10S1P) 16 kwh 50 Ah / 320 V 100 500 2 LFP module (10S1P) 1.6 kwh 50 Ah / 32 V 100 500 2
Smart charging algorithms Driving loads converted from actual driving data 1. Constant charging current (used as the reference) 2. Constant charging power 3. Charging power reduced with increasing SOC 4. Charging power reduced with battery temperature 5. Intemmitent charging
EDISON battery model Key observations from battery model validation SOC, temperature, DOD and internal impedance are important factors to influence battery life. Different charging algorithms can be applied depending on the smart charging needs and type of battery chemistry. EV batteries can successfully deliver power balancing services to the grid when the communication interfaces between the battery BMS, charging inverter and the control room of the grid are standardized for interoperatability. 20
Summary The fluctuating nature of renewable energy challenges the reliability of the energy system and requires high level of flexibility. Smart charging can turn electric vehicles from grid congestion threats to flexibility resources. EDISON project has developed technologies to support intelligent interplay between EVs and power grid, and demonstrated that standardization and interoperatability are key success factors. EV battery could become one of the powerful tools in the flexibility toolbox to enhance the integration of renewable energy in the future energy system. 21
Capacity rating (kwh-mwh-gwh-twh) The future energy landscape Interconnectors Pumped hydro CHP on biogas Interconnectors Green gas Hydrogen CHP peakers Thermal storage Compressed air Electric vehicles Heat pumps Demand response RE firming Supercaps Flywheels Batteries Securing power quality hour day Shifting night and day week Storing for the weather month Leveling the seasons year
Visit www.edison-net.dk to learn more about EDISON project Thank you for your attention Ningling Rao ninra@dongenergy.dk ForskEL Project No. 10426