EWE's approach to double grid connection capacity by using DERflexibility

Transcription

1 EWE's approach to double grid connection capacity by using DERflexibility Marcus Merkel, EWE NETZ GmbH Co-operation workshop of Energy projects Aachen, 19 March 2015

2 EWE approach is in line with the TFSG-EG3-Report (p 8) Possible relations between market roles Prosumers Generator Commercial domain - Supply Supply &flexibility Supplier BRP Flexibility purchase contract Information exchange Aggregator Financial adjustment mechanism BRP Power exchange market Commercial domain - Flexibility Flexibility procurement Distribution network constraint management Grid access & Generation management DSO Mutual exchange of operational and contractual data TSO Balancing Market / Ancillary services Regulated domain

3 Agenda 1 Challenges of RES Integration for EWE NETZ 2 EWE research proposal, analytical proof and smartness 3 Demonstration project and first results 3

4 Distribution networks are the electricity backbone of every region and important for the further economic development Annual power generated from RES/DER has almost reached 70% of total consumption of electricity in The connected RES/DER-generation capacity has exceeded 127% of regional peak power demand. Electricity and natural gas networks Telecommunication networks 4

5 RES development is the major driver for grid expansion in northwest Germany Share of Renewable Energy Sources (RES) in LV and MV networks of EWE NETZ [GWh] 13,6 14,1 14,1 14,2 13,4 13,6 63% 70% 56% 46% 46% 44% 500 % increase in the number of RES installations within seven years (2007 ca / 2013 ca ) 200 % capacity increase for power generated by RES within seven years (2007 ca MW / MW) Share Anteil EERES durchgeleitete Distributed Gesamtstrommenge electricity of EWE NETZ The national targets of the German Government for 2030 are already exceeded in the grid area of EWE NETZ! 5

6 Consumers in the region have stable peak power demand but RES development drives connection capacity on LV/MV RES: wind, solar, biogas, water, gas (in MW) Installed power production (RES) +127% Peak power Demand ** * * preliminary figures ** peak power demand in the electricity networks of EWE NETZ 6

7 2014: Power generation of RES and demand are not aligned upstream and downstream flows have to be managed by EWE NETZ anytime day change day change day change MW MW Green area shows upstream energy flows which are not consumed. Representing reverse flows passing transformer stations from MV to HV networks MW MW MW MW MW MW MW MW MW MW 500 MW 500 MW 0 MW Tuesday Wednesday Thursday Friday 0 MW Consumed electricity Downstream electricity flows Upstream electricty flows 7

8 Regional scenario for 2032 Power production from RES will increase up to 9.2 GW exceeding peak power demand up to 380% 2011 Scenario based on the National grid development plan 2012 (NEP) Biomass Biomasse energy (Base-)Scenario B Regional development for EWE NETZ Photovoltaik Photovoltaics Wind onshore onshore Wind installed power production after years in MW (el.) 8

9 The future proof power distribution system: Need for demand, supply and storage management 380 kv power plants Storage Offshore-Wind-power-plant 220/110 kv EWE NETZ GmbH industrial and commercial users Storage Wind-power-plant 20 kv PV-plant CHP 0,4 kv industrial and commercial users Cogeneration plant Wind-power-plant biogas plant household with storage household with CHP household with PV PV-plant 9

10 Agenda 1 Challenges of RES Integration for EWE NETZ 2 EWE approach: Idea & analytic proof 3 Demonstration, first results & Outlook 10

11 First analytical research based on a RES Szenario in a typical rural distribution network Wahrscheinlichkeitsdichte Probability density [1/MW] Rural MV-grid (including LV) Empirical distribution function for decentralised injection: Verteilungsfunktion Scenario 200% gesamte RES Einspeisung: 200 % Szenario für P [MW] normal abgeregelt Auslastung Utilisation in % Empirical hourly transformer utilisation 110/20 kv: Auslastung Scenario 200% des RES UW-Trafos: 200 % Szenario für t in h normal abgeregelt The analytical relation between power generation and network utilisation 11

12 Examples: resulting injection time series of a onshore wind farm and a PV installation Example 1: Onshore wind farm connected to a transformer station Example 2: PV installation Injection of the windfarm : Scenario 200% RES Injection of the PV installation: Scenario 200% RES! Efficiency is to reduce power peaks only, when congestion occurs and where necessary 12

13 Proposal: Grid connection capacity for RES on DSO level could be doubled by using 5% DG-flexibility Targets of EWE NETZ: Fast & secure connection/ integration of RES on DSO level Grid connection capacity in % Cost reduction on DSO level Dynamic curtailment of max. 5%! 150 by reducing the need for network expansion Dynamic RES-curtailment in % of annual generated energy EWE Proposal Dynamic 5% approach of EWE NETZ according to RES would offer the opportunity to double the grid connection capacity on DSO level 13

14 Curtailment is normally following a static approach to reduce load is this smart? Static curtailment Dynamic curtailment by 5% approach Reduction Reduction Reduction Reduction Dynamic curtailment unloads the network multiple times! 14

15 Example: Distribution Grid Study in Germany indicates that already today RES curtailment of 3% is efficient for DSOs Study Modern power distribution grids for Germany (Distribution Grid Study) From a economic perspective up to 3% static curtailment is already as of today efficient to minimize the grid development costs Source:German Ministry of Economics and Energy, Source:German Ministry of Economics and Energy, 2014 Verteilernetzstudie, page 76 15

16 Agenda 1 Challenges of RES Integration for EWE NETZ 2 EWE approach: Idea & Analytic proof 3 Demonstration, first results & Outlook 16

17 Motivation for our project: Field test 5%-Approach Confirmation, that a load flow dependent reduction of up to 5% of the annual power production of decentralised power generators can be used to double grid connection capacity. Field test with minimised expenditures in a small part of the medium voltage network of EWE NETZ Lighthouse Project of the Federal State Lower Saxony in Germany. The state and EWE demonstrate, how the German Energiewende could become technically and financially feasible Provide research results to use the 5%-Approach in a revised German Energy Industry Act and the Renewable Energy Act Target: Confirm technical feasibility and efficiency of the approach 17

18 The project site is located near Jever/Wittmund in Northwest Germany Source: google.de 11 decentralised power generators are active partners in the pilot project; energy mix of the project site represents average of the EWE el. grid 18

19 Architecture of the control in our field test site (V, I) (V, P, var) (V, I) V = voltage (U) P = power var= reactive power (Q) I= current 19

20 Key elements of the field test Measurement of all electric currents and voltages (transformer station, switchgear, substations) Remote control of all power generators in MV-networks based on agent technology - BTC GRID Agent (agent is based on an industry PC and was originally development for the control of wind parks) Setpoint values of DSO Analog interface mode Possible connection options Field test started on and is planned for a 12 month period 20

21 First measurement results from our field test: line current VZ02 in october

22 First measurement results from the field test: Control of generators is in operation Line current: Solar plant: Wind turbine: 22

23 Development of dynamic curtailment of volatile generation Analytical approach Estimated for 2008: Development of curtailed power In relation to effective feed in In relation to annual feed in Development of curtailed power Measurements october 2014 to january 2015: 23

24 Conclusion & Outlook & Recommendations Confirmation of the technical feasibility of dynamic curtailment approach in the field test by EWE NETZ is almost done. First results from distribution grid operation perspective are positive. The final conclusions will be provided in September A dynamic curtailment approach is providing much more grid capacity than any static curtailment of today. The optimum which was provided in the german distribution grid study of 3% curtailment of annual power could shift to 5% in highly penetrated RES areas. Outlook: Est. revision of the German Energy Act/Renewable Energy Act, costs or value of curtailed power generation; static vs. dynamic curtailment, TSO-DSO interaction and consequences for grid development plans i. Optimization of networks by using EWEs 5% approach to double long term grid connection capacity is possible and feasible. ii. DSOs should be able to negotiate direct contracts with RES generators. iii. DSOs should be at any time in charge to control current and voltages of RES generators to ensure efficient network operation. 24

25 Thank you for your attention! Marcus Merkel EWE NETZ GmbH Cloppenburger Str Oldenburg T.: +49 (0) Dr. Enno Wieben EWE NETZ GmbH Cloppenburger Str Oldenburg T.: +49 (0)

26 Market value of curtailed power in Germany as example to evaluate smart approaches for next generation grid infrastructures Recommendation: DSO should be able to compare long term grid development costs with the costs of curtailment (incl. all related costs of operation) Value of curtailed power could be handled as replacement purchase based on spot market prices Market values for wind and solar prices are already available à System Services procurement of a DSO Market prices wind onshore Market prices PV Average The average would be roughly 36 EUR/MWh. As market prices may rise DSOs need clear rules to determine the value of this flexibility. 26