Bruno Cova ResponsabileArea di Business Power Systems, Markets and Regulatory Division Consulting, Solutions & Services. Firenze, 12.4.

Transcription

1 Valutazione del livello di massima penetrazione della generazione da fonte rinnovabile non programmabile Assessing the maximum penetration level of non programmable RES generation Bruno Cova ResponsabileArea di Business Power Systems, Markets and Regulatory Division Consulting, Solutions & Services Centrale eolica di Sidi Daoud (54 MW) - Tunisia

2 Agenda Trends towards a progressive decarbonisation of power systems Increasing penetration of power generation from nonprogrammable RES Problems to overcome to enhance generation from nonprogrammable RES Methodology to assess the maximum feasible penetration of non-programmable RES The CESI experience

3 Agenda Trends towards a progressive decarbonisation of power systems Increasing penetration of power generation from nonprogrammable RES Problems to overcome to enhance generation from nonprogrammable RES Methodology to assess the maximum feasible penetration of non-programmable RES The CESI experience

4 Power generation in the world Power Generation from main energy sources World power production: ~ TWh Source: Enerdata Yearbook 2011 / CESI elaborations 4

5 Power generation in the Arab Countries Power Generation from main energy sources Typical specific CO2 emissions (kg/mwh) Arab Countries power production: ~907 TWh Coal Oil Gas OCGT Gas CCGT Source: AFESD project / CESI elaborations 5

6 Trends towards a progressive decarbonisation of power systems: the Arab Countries Despite the actual poor penetration of RES generation, the Arab Countries, namely in North Africa, are setting ambitious targets for the deployment of RES generation in their territory. At a short term the priority is the exploitation of the enormous wind and sun potential for their internal demand. Targets of RES penetration in North Africa Country Penetration rate (*) Target year Morocco 42% 2020 Algeria 40% 2030 Tunisia 13.5%-22% (**) % (***) 2030 Libya 10% 2025 Egypt 20% 2020 (*) Assessed as ratio of RES generation over internal demand on yearly basis (**) previous scenario (***) recently approved scenario 6

7 Trends towards a progressive decarbonisation of power systems: the Arab Countries The possibility of making business through export of RES generation to Europe is seen as a mid-long term perspective for a series of reasons (lack of infrastructures, different regulatory frameworks, different trading rules, need for enhanced transparency,etc.),.but it can be speeded up by undertaking a coordinated process of harmonisation of power markets and cross-border trading regulation. Capacity (GW) Wind Potential Capacity (GW) Solar Potential 7

8 Increasing penetration of power generation from non-programmable RES RES generating capacity in Europe [GW] +68% Total RES capacity Which problems already experienced in Europe? Source: ENTSO-E TYNDP 2012 Scenario EU

9 Agenda Trends towards a progressive decarbonisation of power systems Increasing penetration of power generation from nonprogrammable RES Problems to overcome to enhance generation from nonprogrammable RES Methodology to assess the maximum feasible penetration of non-programmable RES The CESI experience

10 Problems to overcome to enhance generation from non- programmable RES Additional reserve and balancing capability Risk of overgeneration in low loading conditions Difficult transitions in the ramp up/down hours Curtailed RES generation!!! Network congestion Voltage profile and reactive power management Critical behaviour of the system in dynamic conditions 10

11 Problems to overcome to enhance generation from non- programmable RES Load following in case of enhanced PV generation demand No correlation between wind/sun generation and demand! wind Difficult transitions during load ramp up/down Gradient of generation Load Request Difficult upward/downward transitions Example of Spain Time (min) Wind + Solar 11

12 Problems to overcome to enhance generation from non- programmable RES Risks of RES generation curtailment depending on: (In)flexibility of power plants (in)adequacy of the transmission /distribution infrastructures (including cross-border lines) Possibility of energy storage Demand responsiveness Different feasible penetration levels of non-programmable RES generation Curtailed non-progr. RES gen. 40% 35% 30% 25% 20% 15% 10% 5% 0% 28% 22% 16% 10% 5% 1,000 2,000 3,000 4,000 5,000 Installed RES capacity [MW] RES penetration for each area 12

13 Methodology to assess the maximum feasible penetration of non- programmable RES Maximisation of RES generation penetration while minimising the risk of curtailment: a FOUR-LAYER TOP-DOWN APPROACH Reserve Criterion 2. Network connection / Static Analysis 3. Reliability Analysis 4 3. Reliability Analysis 4. Dynamic Analysis 13

14 Methodology to assess the maximum feasible penetration of non- programmable RES 1. Reserve criterion First evaluation of maximum RES penetration that can be accepted by the system taking into account the additional reserve to face the unpredictability of RES 2. Network connection / Static analysis Distribution of RES installed capacity The best connection points of RES units on the network 14

15 Methodology to assess the maximum feasible penetration of non- programmable RES 3. Reliability analysis Three meaningful Risk Indices : Loss Of Load Expectation Loss Of Load Probability Expected Energy Not Supplied Reliability of the system to fulfil power demand The maximum RES penetration compliant with reliability standards Risk of wind /solar curtailment due to network element overloads, lack of interconnection or minimum stable operation of conventional units in low load condition Possible network reinforcements, new storage devices and reserve margins able to preserve the static reliability and the security of the system 15

16 Methodology to assess the maximum feasible penetration of non- programmable RES 4. Dynamic Analysis Measures to avoid any RES production restriction due to dynamic constraints Check the fluctuations due to RES production intermittency Analysis of network response to major fault events Fault Ride Through characterisc 16

17 Methodology: layer 1-the reserve criterion Single Busbar model Secondary and Tertiary reserves are sized to manage the frequency error and the largest generator tripping Additional reserve to face the unpredictability of RES is estimated Acceptable gradients of max power increase/decrease are taken into account to confirm the limit of non-dispatchable generation RES energy feed points and network constraints are not considered yet 17

18 Methodology: layer 1-the reserve criterion Max{RES} = Demand - ( i P MIN-i + Tertiary reserve + Additional reserve) P i MAX i Secondary increase reserve Tertiary increase reserve Renewable production Traditional generation P i MIN i Secondary decrease reserve Additional reserve for RES Tertiary decrease reserve 18

19 Example: predominantly thermal based power system Min. load: 5700 MW Assumption: isolated system P wind wind = 850 MW Wind penetration rate: 15% Max. load: MW P wind P PV wind = 850 MW PV = 3170 MW Wind+PV penetr. rate: 26.7% 19

20 Effects of Interconnections ( maquette maquette model representing countries of Maghreb) Isolated System No Export Wind+PV penetration: : 26.7% (*) Interconnected System (S-S links) Export AC: 500 MW (to other Maghrebian countries) Wind+PV penetration: 28.6% Integrated System (S-S S & S-N links) Export AC: 500 MW (to other Maghrebian countries) Export HVDC: 1000 MW (to Europe) Wind+PV penetration: 32.3% (*) Ratio referred to a peak load condition (15 GW) 20

21 Possible solutions to enhance penetration of non-programmable RES Higher flexibility of conventional generation Lower technical minimums different policies for unit commitment : higher rate of start up/ shut down of unit : OC TG Energy storage Two levels: 1. small scale to smooth high frequency low amplitude intermittency: batteries at s/s 2. large scale for system wide stabilisation: hydro pumping / large size batteries Demand responsiveness Demand response from users. including electric vehicles 21

22 The role of transmission infrastructure: the electricity highways Source: EC 22

23 Agenda Trends towards a progressive decarbonisation of power systems Increasing penetration of power generation from nonprogrammable RES Problems to overcome to enhance generation from nonprogrammable RES Methodology to assess the maximum feasible penetration of non-programmable RES The CESI experience

24 CESI experience Ireland, NIE Transmission development plan to integrate RES generation Italy, Terna Development Plan for RES integration to National Transmission grid Poland Romania Crete Turkey, ENEL Maximum penetration of RES (wind and solar generation) Morocco, ENEL Maximum penetration of RES Tunisia, ELMED Wind integration studies Libya, REAOL Wind integration studies Jordan, MEMR (NEPCO) Wind integration study 24

25 RES4MED and CESI The detailed methodology to assess the maximum penetration of nonprogrammable RES generation is presented in the WG report led by CESI in the context of RES4MES activities 25

26 Milan Berlin Mannheim Dubai Rio de Janeiro