Storage Applications in the Italian Transmission Grid to facilitate RES integration

Transcription

1 Storage Applications in the Italian Transmission Grid to facilitate RES integration Angelo Ferrante Rome, June 13 th 2012

2 Terna and the Italian EHV-HV Transmission Grid Facts and figures Owner of more than 98% of the Italian EHV-HV Transmission Grid: Francia 380 Venaus- Villarodin Francia 380 Albertville- Rondissone Francia 380 Albertville- Rondissone Francia 220 Camporosso- Brioccarros Svizzera 380 Musignano- Lavorgo Svizzera 380 Bulciago- Soazza Svizzera 380 Gorlago- Robbia Svizzera 380 Sfiorano- Robbia Svizzera 220 Avise- Riddes Svizzera 220 Mese- Gorduno Svizzera 220 Valpelline- Riddes Svizzera 220 Pallanzeno- Serra Svizzera 220 Ponte- Airolo Austria 220 Soverzene- Lienz Slovenia 380 Redipuglia- Divacca Slovenia 220 Soverzene- Lienz Over km of EHV and HV lines km of 380 kv lines, km of land and 917 km of submarine cables, Over 445 substations 122 GVA transforming capacity 22 interconnectors France (4+1), Switzerland (9), Austria (1), Slovenia (2), Greece (1) Responsible for planning, development, operation and maintenance of the NTG, as well as for the transmission and dispatching activities 332 TWh: energy demand in 2011 ( +0,6% vs 2010) Peak demand: 56.5 GW (13 July 2011) 1 st fully unbundled SO in Europe and 7 th in the world 2

3 The TERNA Group Updated Group structure Subsidiaries Joint ventures Associates Companies evaluated using the equity method 3

4 Ownership structure Share capital divided according to reference areas Updated as of April,

5 Development Trend of RES Power Capacity in Italy (MW) Installed Capacity from Wind and Solar Power Plants * Italian Government targets: (*) December 2011 provisional data MW (IV Conto energia) MW (target PAN 2020) 5

6 Evolution of the generation scenario Development of the renewable energy generation capacity* (MW) Installed wind and PV power Short-medium term forecasts Wind Wind PV PV (*) Provisional data December

7 Impact of fluctuating RES generation on power system Current difficulties and possible envisaged problems Main impacts Power Flow inversion in 150/20 kv distribution substations and local HV grid congestions Increase of congestions on 400 kv network in daily off peak conditions Balancing of generation surplus in very low load condition Security issues (frequency stability, lack of primary reserve, evening ramps) Further impacts expected in the short-medium term horizon Extension of network congestions to further grid portions in South Italy National and zonal (South Italy and Sicily) Over-Generation that cannot be balanced 7

8 Impact of fluctuating RES generation on power system Power Flow inversion Annual data 2011 vs HV transmission grid 150 kv 325 (9%) Total HV/MV sections in Italy Inversion >1% (>87 h/ year) 543* (17%) 252 (7%) Inversion >5% (>438 h/ year) 358* (11%) 20 kv MV distribumon grid (*) provisional data end 2011 / Source: ENEL Distribuzione 8

9 Impact of fluctuating RES generation on power system Local HV grid congestions Surplus of installed RES vs load + energy transfer capacity SE 380/150 kv Grounds for limiting the production of intermittent RES: Solve local grid congestions Security of the 150kV grid Compliance with reserve requirements for secure operation of insular grids 9

10 Impact of intermittent RES on reserve and balancing Risks for lack of regulating capacity margins Primary reserve The increase of intermittent RES implies an equivalent reduction of the conventional generation required for providing primary reserve Secondary reserve/ Tertiary reserve The power produced by intermittent RES determines a further level of uncertainty for real-time balancing of production and load The increase of intermittent RES generation increases reserve needs but, at the same time, reduces reserve availability 10

11 Effects of Huge Amount of RES on Generation Dispatching Impact on System Reserve and Power Balancing PV generation Load Load PV Not predictable RES Minimum Thermal capacity necessary for system security Minimum Import Not dispatchable generation Constraints on use of regulaeng plants Maximize use of exiseng hydro- pumping power plants Import reduceon Massive use of defense systems D1 D2 D3 Risks of modulaeng RES generaeon 11

12 Relieving congeseons Effect of storage devices on a congested line Limit (transmission capacity) Curtailed intermittent energy Curtailment reduction (storage) Energy from ESS Stored intermittent energy Dispatched Intermittent production 12

13 Law Decisions on Electricity Storage Planning, Realization and operation of electricity storage devices Dlgs 3 march 2011, n. 28 projects of new electricity storage plants aimed at supporting RES integration projects included in the TNDP Regulator provides for remuneration of investments Dlgs 1 June 2011, n. 93 Terna and Distributors can build and operate storage plants with batteries hydro-pumping power plants included in the TNDP are awarded by competitive procedures. Delib. ARG/elt 199/11, I3 incentives ( WACC: 2% 12yrs) for investments allowing to: reduce congestions between market zones; increase Net Transfer Capacity (NTC); reduce intrazonal congestions, subject to approval of AEEG I4 incentives ( WACC: 2% 12yrs) for pilot projects on ESS (TSO and DSOs) 13

14 Analysis of the technical solutions Typical capacity values vs discharging time* Focusing on energy intensive and flexible solumons, to be developed within next 2 years InvesMgaMng technical solumons able to take advantage of exismng substamons in order to reduce environmental impact and permizng Mmes * Electricity Storage AssociaMon (November 2008/ Ref. to installed devices ) 14

15 Advantages of Batteries Installation of batteries vs BAU (grid development as the only solution) Batteries BAU Congestion reduction Underutilization of the grid (<10%) Primary reserve Tertiary reserve Only if available in neighbouring area Limited implementation time Modular, capillary and removable Limited impact on the territory 15

16 ESS sizing Recovered energy assessment FIRST STEP (130 MW) Expected results Avoid curtailment of about 230 GWh/yr from RES Provide additional tertiary reserve on the market for approximately 410 GWh/yr GWh/a * SECOND STEP (+110 MW) Expected results Avoid curtailment of about 440 GWh/yr from RES Provide additional tertiary reserve on the market for approximately 750 GWh/yr 16

17 A B C D Benefits evaluation The following overall benefits should be assessed: Reductions in the cost of energy: Storage of RES energy when the grid is congested and then possible release of the energy stored, replacing equivalent conventional thermal energy Increase of the adequacy/security margins: Meet the increased needs for secondary and tertiary reserves. Compensation of the frequency regulation capacity reduction of the system frequency/power adjustments. Reduced costs for new HV lines and increased voltage regulation capacity Performance index = (A+B+C) NPV benefits CapEx - D A B C D Benefits for the system Energy: reduced curtailment Security: secondary tertiary reserve Security: primary regulation Security: reduced costs for new HV lines 17

18 Benefit /Cost ratio of a 240 MW batteries investment Benefits Mln / year* PI = Benefit/Cost raeo > 1,8 Avoiding to cut RES Energy 60 Costs Mln /year* Primary reserve resources for system security Ba_eries CAPEX + OPEX Secondary and tereary reserve resources for system balancing Avoid Network investments 8 7 * Actualized benefits and costs in the lifemme horizon of 15 years 18

19 Conclusions Strategies for integration of RES into the national power system Investments planned by Terna for a stronger smart transmission system More than 2,5 Billion within next 5 years to develop transmission network infrastructures distributed storage devices Energy Policy Makers to be aware: Embedded generation to be compliant ASAP with grid requirements Fluctuating RES (esp. on MV and LV side) to improve their production forecast and to make available system regulation services Review market rules to realize more efficient price signals effective markets coupling 19

20 Thank you for your attention! 20