State-of-the-Art development in distribution grid operation under the constraint of large RE contribution

Transcription

1 State-of-the-Art development in distribution grid operation under the constraint of large RE contribution Oldenburg, 19. November 2013 Dr. Johannes Rolink, R & D, EWE AG

2 Content 1 Facts about EWE 2 Regulatory framework for the integration of RES 3 Planning of distribution grids 4 Feed-in management 5 Transformer overloading prediction 6 5 %-Approach 7 Summary 2

3 EWE - the future of energy from a single source EWE brings together energy, telecommunications and information technology and therefore has all the key competencies for sustainable, intelligent energy supply systems at its disposal This means that the company can develop and operate modern energy supply systems from power generation to network management and from storage to energy use entirely in-house An energy industry pioneer: innovativeness and the focus on integrated infrastructure are the key to EWE's success Strong regional roots: customer proximity and a knowledge of the region's infrastructure drive local energy solutions for local people 3

4 EWE group key figures Figures for 2012 Electricity Natural gas TC Clients 1.4 million 1.6 million 670,000 (incl. htp clients) Sales 19.0 billion kwh 59.4 billion kwh Network 92,000 km 69,000 km 35,000 km EWE Group 9,049 employees (average for the year) 4,693 employees (average for the year) 8.2 billion sales 4.66 billion sales million consolidated million net net profit profit for the for the year period million capital expenditure 4

5 EWE our areas in Germany, Poland, and Turkey Head office EWE AG 5

6 EWE - installed capacity of RES Fig.: Installed capacity of RES in the EWE grid area 6

7 EWE - electricity production of RES Full Vollbenutzungsstunde hours of use n Wind: Windenergie: h/a PV: 820 h/a h/a Biogas: Photovoltaik: h/a 820 h/a electricity consumption 2010 Biogas: h/a feed-in RES 2010 pot. feed-in RES 2022 pot. feed-in RES 2032 Electricity production of RES in the EWE grid area 7

8 Regulatory framework for the integration of RES German Renewable Energy Act (EEG 2012) Target: support the RES in Germany Local SO have to integrate RES immediately ( 5) Large RES must be equipped with a control system in order to reduce power in case of congestions ( 6) Connection SO has to take over the electricity of the RES ( 8) In case of too less hosting capacity, grid optimization, strengthening, or expansion of the grid is mandatory ( 9) Permission for feed-in manangement to prevent the grid from overloadings ( 11) (followed by optimization, strengthening, or expansion) 8

9 Planning of distribution grids Past: Unidirectional power flow Maximum load situation relevant Present: Installed generation capacity partly exceeds the max. load Bidirectional power flow Design situations maximum load / minimum infeed maximum infeed / minimum load! Oversizing of the grid infrastructure for most of the time Load of a secondary substation (schematic)! Max. loading depends on the coincidence of load and generation 9

10 Feed-in management Example alert threshold Fig.: Current profile of a substation (110 kv/20 kv) 10

11 Feed-in management Feed-in management acts like a closed loop control 380 kv (TENNET) measurements control center TENNET priority 1 transformers 110 kv (E.ON) measurements control center E.ON priority 2 transformers 20 kv/0,4 kv (EWE Netz) measurements control center EWE Netz priority 3 100% / 60% / 30% / 0%* * according to VDE-AR-N 4105 and BDEW: Erzeugungsanlagen am Mittelspannungsnetz 11

12 Feed-in management Fig.: Feed-in management operations at EWE Netz 12

13 Feed-in management Fig.: Feed-in management operations at EWE Netz 12

14 Transformer overloading prediction (TOP) Capacities in the grid can not be fully utilized, as Generation and load predictions are only available on a global level the (maximum) loading of the facilities is not really known these limits are not predicted Prediction of the capacity utilization of 40 substations of EWE NETZ under consideration of dynamic data of the topology and measurements integrated prediction of generation as well as a transformer and loading model Economic benefit: Avoidance of transformer damages Optimized use of the assets as well as avoidance of invest costs Prevention of compensation of EEG funded power plants Temperature model Forecast generation Forecast load State estimation Evaluation Prediction overloading Alert Grid topology Schematic representation of TOP 13

15 5 %-Approach Example: Permanent limitation of maximum power 87 % loss of energy: 5 % 54 % Fig.: Annual duration curve of a PV-system (standardized)! Maximum power can be reduced significantly accepting a minor loss of energy! Limitation is not permanently necessary! 14

16 5 %-Approach Hosting capacity [%] Source: Dr. Enno Wieben, EWE Netz Loss of energy p. a. [%] Fig.: Hosting capacity with dynamic power control 15

17 5 %-Approach Approach: Dynamic control depending on the load and infeed situation Hosting capacity [%] Source: Dr. Enno Wieben, EWE Netz Loss of energy p. a. [%] Fig.: Hosting capacity with dynamic power control 15

18 5 %-Approach Approach: Dynamic control depending on the load and infeed situation Hosting capacity [%] Source: Dr. Enno Wieben, EWE Netz Loss of energy p. a. [%] Fig.: Hosting capacity with dynamic power control! More than twice as much hosting capacity at 5 % loss of energy 15

19 5 %-Approach Approach: Dynamic control depending on the load and infeed situation Hosting capacity [%] Source: Dr. Enno Wieben, EWE Netz Loss of energy p. a. [%] Fig.: Hosting capacity with dynamic power control! More than twice as much hosting capacity at 5 % loss of energy! Weather predicitions can help to facilitate/improve the approach 15

20 Summary DSOs have to cope with an increasing share of RES Change of paradigm in grid planning and operation (e. g. feed-in management) New methods (e.g. TOP & 5 %-Approach) are needed to face these challenges Weather forecasts can play an important role in order to facilitate grid operation 16

21 Thank you very much for your attention! EWE Aktiengesellschaft Tirpitzstraße Oldenburg, Germany T