FORECASTING IN SYSTEM OPERATION

Transcription

1 FORECASTING IN SYSTEM OPERATION SANEDI, Sandton, South Africa, Knud Johansen, chief engineer Forecasting in system operation and planning September

2 AGENDA Brief introduction to Energinet the Danish TSO The Danish electricity system today ~ 42% wind power System operational and planning Forecasting in system balancing Forecasting in system operation and planning September

3 ENERGINET We own and operate the overall electricity and natural gas transmission system in Denmark. Our tasks are to integrate renewable energy and ensure security of supply in Denmark Independent public enterprise owned by the Danish Ministry of Energy, Utilities and Climate ~ employees 8 locations and headquarter in Fredericia, Denmark Mission to ensure reliable energy for society Vision to create balance in a renewable energy system

4 COMPANY STRUCTURE Engineering and Construction Business Services ELECTRICITY TSO GAS TSO Tx Operator System balancing Forecasting in system operation and planning September

5 POWER GRID 6,913 km transmission grid 3,770 TWh-km transmitted 8 International interconnections Forecasting in system operation and planning September

6 THE ENERGY SYSTEM IN DENMARK IS CHANGING By 2020, wind power will constitute 50% of the electricity consumption By 2050, Denmark must be completely independent of fossil fuels Strategic commitments of Energinet: - Security of supply - Efficient green transition - Healthy investment climate Forecasting in system operation and planning September

7 AGENDA Brief introduction to Energinet the Danish TSO The Danish electricity system today ~ 42% wind power System operational and planning Forecasting in system balancing Forecasting in system operation and planning September

8 THE DANISH ELECTRICITY SYSTEM CAPACITY BALANCE Forecasting in system operation and planning September

9 INSTALLED CAPACITY - RENEWABLES Forecasting in system operation and planning September

10 THE DANISH ELECTRICITY SYSTEM ENERGY BALANCE Energy balance 2015 Demand incl. losses Large CHP Local CHP Wind power PV Import Exports 33.6 TWh 9.2 TWh 3.8 TWh 14.1 TWh 0.6 TWh 15.5 TWh 9.6 TWh Forecasting in system operation and planning September

11 AGENDA Brief introduction to Energinet the Danish TSO The Danish electricity system today ~ 42% wind power System operational and planning Forecasting in system balancing Forecasting in system operation and planning September

12 OPERATIONAL PLANNING TOOLS Energinet has developed two essential IT tools to manage the large amount of renewable generation: Operational Planning System: providing information on imbalances in the coming hours on the basis of forecasts, updated generation plans and on-line measurements Distributed Generation Management System: providing the basis for forecasting of renewable generation and grid security limits calculations (grid constraints) Forecasting in system operation and planning September

13 OPERATIONAL PROCEDURES AND TOOLS Operational planning based on best possible predictions at any time Minimize needs for automatic reserves and ancillary services Balance system with least cost resources slow manual reserves Detailed and continuously updated knowledge allows operation closer to the limits All operational facets are providing security of supply More efficient and safe to be prepared than surprised! Forecasting in system operation and planning September

14 DISTRIBUTED GENERATION MANAGEMENT 6,300 generators distributed on 4,600 power plants 75 plants with individual schedules and 4,525 plants without 20 Balance Responsible Parties for generation 6 Balance Responsible Parties for demand / flexible demand 97,300 power generation units with self-governing control according to the grid code requirements Area 1 Area 2 Data management for Generation forecasting Flexible load forecasting Load flow analysis Substation 1 Substation 2 Substation 3 Forecasting in system operation and planning September

15 OPERATIONAL PLANNING SYSTEM - CONTINUOUSLY UPDATED SCHEDULES AND FORECASTS Actual prediction Forecast day-a-head SCADA measurement and up-scaling Forecasting in system operation and planning September

16 OPERATIONAL PLANNING SYSTEM - PREDICTED IMBALANCE ON-LINE UP-DATED Closing the gap before the operating hour Predicted Imbalance Forecasting in system operation and planning September

17 BALANCING OPERATIONS Schedules Actual Reg. power Final settlement Reg. power + + Operational hour Forecasts Reference for final settlement = Regulating power dispatch Final settlement Selling to Energinet Buying from Energinet One hour before the operational hour (H-1): Market is closed, and Energinet is responsible for the final balancing Forecasting in system operation and planning September

18 AGENDA Brief introduction to Energinet the Danish TSO The Danish electricity system today ~ 42% wind power System operational and planning Forecasting in system balancing Forecasting in system operation and planning September

19 WHY DO WE MAKE FORECASTING? Balancing 62% of the consumption covered by wind power in December 2015 Average: 42% Reserve estimation Day ahead power balance estimation Trade transmission loss and production under a purchase obligation. Transparency Forecasting in system operation and planning September

20 WHAT DO WE FORECAST? The forecasting team is responsible for providing 5 min to 1 year ahead forecasts. Current forecasts: Wind power production Solar power production Local CHP production Transmission loss Consumption / demand Flow on tie-lines Forecasting in system operation and planning September

21 THE DAILY POWER MARKETS Financial markets Spot market Intraday market Regulating market 12:00 Day ahead Operating day 1 hour for TSO to prepare physical balancing Forecasting in system operation and planning September

22 FORECASTING INFORMATION Forecasts are retrieved from the weather forecast providers and stored in a file share at Energinet. Input from in-house forecasts are stored redundantly with other relevant forecast data. Forecast providers are: DMI (local model) ECMWF (global model) ConWx (local model) Forecast parameters are: Temperature measured at heights of 2 m and 100 m Wind speed and wind direction measured at heights of 10 m and 100 m Global radiation Forecasting in system operation and planning September

23 FORECAST INFORMATION BASEMENT Provided on a 15km x 15km grid Forecasting in system operation and planning September

24 WIND POWER FORECASTING Forecasting in system operation and planning September

25 WIND POWER FORECASTING TOOLS We use two forecasting tools one external and one internal External forecast Provider: Enfor A/S Online forecast (0-12 hours) every 15 minutes Day ahead forecast (0-48 hours) every hour Internal forecast Online forecast (0-10 hours) every 5 minutes Day ahead forecast (0-192 hours), triggered by new weather prognosis Each forecast is based on weather prognosis from three service providers Forecasting in system operation and planning September

26 INTERNAL FORECASTING PROCESS Wind speed Production data Installed capacity UTM coordinates SCADA data Model Wind power forecast Forecasting in system operation and planning September

27 WIND POWER FORECASTING PERFORMANCE + on-line measurements Forecasting in system operation and planning September

28 PHOTO VOLTAIC FORECASTING Forecasting in system operation and planning September

29 PHOTO VOLTAIC POWER COVERAGE, 2015 Forecasting in system operation and planning September

30 PV FORECASTING - CLEAR SKY MODEL Where T is a constant, P P inst a L cos T dt, dt: time to closest solar noon L: distance of radiation through the atmosphere a: day-of-year parameter Forecasting in system operation and planning September

31 PV FORECASTING PROCESS F t = w t nwp t + b t, Forecasting in system operation and planning September

32 FORECASTING PERFORMANCE DAY AHEAD dk1 (518 MW): Mae Rmse Bias 9,1 MWh 18,9 MWh -1,5 MWh dk2 (266 MW): Mae Rmse Bias 4,7 MWh 10,1 MWh -0,4 MWh Forecasting in system operation and planning September

33 CONCLUDING REMARKS Energinet experience during the last 30 years can be summarized as follows: Flexibility and dynamics in the conventional energy sources is flooring the way for renewables. No rocket science involved just practical aspects don t try to change the nature, but try to adapt to the variability of the natural resources when they are available. Don t curtail the gift from the nature use it optimal. Don t fix run schedules several days in advance, but adjust the schedules as the forecasts evolves and gets more and more accurate. One hour before the operational second the overall forecast accuracy is reduced to 1.5 % when the NCC takes over the balancing task. Based on cost efficient manual reserves the balance is obtained instead of using expensive automatic reserves. The automatic reserves is assigned to balance the last remaining deviation. This gives a better security of supply at a lower cost. It s still better to be prepared than surprised Forecasting in system operation and planning September

34 ADDITIONAL SLIDES Forecasting in system operation and planning September

35 SOUTH AFRICA COMPARED TO DENMARK Reference: Forecasting in system operation and planning September

36 DAILY PLANNING We want to know the balance in advance to be able to control the system in the most efficient way. With an increasing amount of renewables we need all possible regulating reserves in the system. Detailed knowledge of production, consumption and exchange provides the basis for good grid security calculations which allow us to operate the grid closer to the limit. Balance = Demand + Wind Power + CHP + Conventional Power + Exchange, Demand, on-shore Wind Power and a part of CHP is based on prediction and templates CHP, off-shore wind power, conventional power and exchange is scheduled by the market players. The schedules shall be updated if the deviation is more than 10 MW. Schedules is encourage by a speciel power settlement. Forecasting in system operation and planning September

37 POWER CURVE CHALLENGE With more than 5 GW wind power installed, a change of 1m/s in wind speed can result in a change of more than 500 MW in wind power produced The meteorological forecasts rarely agree on the same wind speed. Thus we constantly look for the best combination. Forecasting in system operation and planning September