Energy Transition and Power Systems An analysis from the Italian to the European context. Marco Merlo Politecnico di Milano Energy Department

Transcription

1 Energy Transition and Power Systems An analysis from the Italian to the European context Marco Merlo Politecnico di Milano Energy Department

2 Outline First of all: what are we talking about? Smart Grid: what are they? Storage: do we really need it? Energy Ecosystem: looking for a solution? 2

3 What we are talking about????? 3

4 Outline First of all: what are we talking about? Smart Grid: what are they? Storage: do we really need it? Energy Ecosystem: looking for a solution? 4

5 a very wide paradigma AEEG DECISION 5/10 AEEG DECISION 242/10 Main focus of this presentation wind integr. V-2-G SERVICES RECHARGING INFRASTRUCTURE E-mobility AEEG DECISION 39/10 active grid ELECTRIC VEHICLES VOLTAGE REGULATION DISTRIBUTED GENERATION LARGE SCALE INTERMITT.GEN. STORAGE SYSTEMS storage DR & EE DEMAND RESPONSE DISTR. NETWORK AUTOMATION MICRO GENERATION DEMAND AGGREGATION ENERGY EFFICIENCY SMART APPLIANCES AEEG DECISION 103/03 ELECTRONIC METERS smart metering SUPPLIER DISPLAYS AEEG DECISION 292/06 SMART POWER SYSTEMS 5

6 INPUT BASED TARIFF INCENTIVES Electricity networks: extra remuneration guaranteed up to 8 12 years for new strategic investments aimed at: reducing congestion in transmission networks facilitating network modernization (not quality) promoting innovation (smart grid demo projects) Remuneration for new selected investment is currently between 9% 10% in real terms before taxes Electricity WACC Max Incentive Distribution 7 % +2% Transmission 6,9 % +3% Metering 7,2 % 6

7 Key features of demo projects Real grid: A real case in existing distribution networks: real grid, real customers and real generators Focus on DG integration in MV networks [1 35 kv]: 75% of DG power Active grid: the selected MV network has to be characterized by a reverse power flow At least 1% of yearly time with reverse power flow from MV level to HV Automated & controlled grid: the selected MV network has to be controlled (voltage limits / anti islanding) Real time control system at MV level Open grid: non proprietary communication protocols only minimize customer costs at the network interface 7

8 costs and benefits: Many technical and economic features of the Smart Grid, Distributed Generation and Demand Response provide diffuse benefits to the customers that are hard to put a value on. Regulators must engage in lenghty proceedings to set methods of measuring the value and then utilities must administer them under the critical eye of regulators P. Fox Penner, Smart Power,

9 KPI APPROACH in ITALY Synthetic indicator used to assess the expected performance of the selected projects Quantitative cost and main benefit indicator IP P smart P smart EI C m j i EI 8760 post Further benefits qualitative scoring Aj pre IP: priority index Aj: project benefits [point score] C:projectcosts[ ] P smart: increase in DG produced electricity / hour [MW] EI post: DG produced electricity that canbeinjectedinthenetworkafter the project in safe conditions [GWh] EI pre: DG produced electricity that can be injected in the network before the project without reverse flow [GWh] 9

10 hosting capacity at network level P DG Vcontrol HV MV 1% of time Smart network latency 200 ms: + storage P smart Smart network latency 200 ms remote intertrip (no islanding)* Smart network latency10 20 s remote voltage regulation MV LV MV LV Min. Load P DG =0 Passive network: NO flow from MV to HV * Very critical in Italy due to fast reclosure ( ms) Psmart istheincreaseindg production that can be connected to the grid in secure conditions thanks to smart investments on the grid 10

11 TLC architecture The Project entails modifications on: SCADA systems, HV/MV substations, secondary substations, MV active/passive users, ICT and final LV customers. LEVEL 0 CONTROL CENTER X LEVEL 1: PRIMARY SUBSTATION REMOTE BUSBAR X X RPS X WIMAX (+ fiber optics) LEVEL 2: SECONDARY SUBSTATION RSS Data Concentrator LEVEL 3: INTERFACE USER/DSO X LEVEL 4: ACTIVE MV USERS PASSIVE MV USERS X RUA X Wh PROTECTION MONITORING CONTROL DEVICE PASSIVE LV USERS Smart Meter Smart Info 11

12 Innovative functions 1. Automatic selection of faulty branches (Logical Selectivity, LS) 2. Innovative DG Interface Protection with transfer trip 3. Voltage control (local control/centralized control) 4. Limitation/regulation of active power in emergency (with the TSO) 5. Monitoring of DG injections (jointly with the TSO) 6. Managing recharging infrastructure for electric vehicles 7. Enabling demand-response strategies through the Smart Info 12

13 1. Automatic selection of faulty branches Goal of the function: to isolate the network section affected by a fault without opening the Circuit Breaker (CB) atop the feeder (even in the case of 3ph faults). The Feeder Relay (FR) in PS, in case of fault detection, waits before tripping, and within an appropriate time window, for a so called BLOCK signal, coming from at least one of the Fault Passage Indicators (FPI) downstream. If the BLOCK is received, the relay will not open the FR: the signal assures that at least another device along the feeder is going to open its breaker to clear the fault. The same strategy is used to coordinate all CB along the feeder: each CB is driven by its FPI; in case of fault, each FPI waits before tripping for BLOCK signals coming from downstream. The only FPI not receiving a BLOCK will open its CB. In any case, even if a FPI has received a BLOCK, the CB opens if the fault condition does not fall within an appropriate time-out. Thanks to the always-on connection, each FPI can be quickly reconfigured in case of network topology variation. 13

14 An Example When a fault occurs in a section of the line all CBs (1, 2, 3, PS), in case of fault detection, wait before tripping the FPI nearest to the fault, activated by the fault current, blocks the CB upwards the grid (in PS and SS) with a BLOCK signal to the relevant FPI the only FPI not receiving any blocking order opens its CB and clears the fault BLOCK SIGNAL BLOCK SIGNAL BLOCK SIGNAL PS FPI 1 FPI 2 FPI 3 FPI 4 PS SS1 SS2 SS3 SS4 Closed CB Open CB Communication system 14

15 2. DG Interface Protection Relay with transfer trip Goal of the function: to solve the issues related to the IPR and disconnect DG when loss of main occurs. The transfer trip function operates in a fail-safe mode. During a fault, the FPI that opens its CB, also sends a transfer trip command to each DG protection relay (IPR) that is located downstream its position, thus ensuring a forced disconnection of the relevant DG from the network. FPI periodically checks for the presence of the TLC network by keep-alive: When communication is active ( keep alive received) a low sensitivity setting profile of voltage/frequency protections is enabled in IPR (f.i. 47,5-51,5 Hz), together with a transfer trip: DG disconnects only if LoM occurs. If the communication fails (a keep alive test is performed f.i. every 5 s) the relays come back to the local operation (the same of today, 49,7 50,3 Hz) 15

16 CLOSED OPEN 0MW P C P G CP RECLOSURE KO 1MW 1MW 51,5 Hz IPR DDI P C P G CLOSED OPEN 0MW RECLOSURE OK 1MW UT.2 2MW 1MW 47,5 Hz 51,5 Hz IPR 1MW 2MW DDI 1MW UT.1 2MW 47,5 Hz 2MW 2MW 16

17 3. Voltage control In the first stage of the Project a simplified control strategy is adopted: each generator operates without coordination with other generators or network devices (local voltage control) when a particular voltage threshold is reached (e.g Vn) DG is controlled to absorb reactive power if this action is not enough, it is also possible to curtail the injection of DG active power In a further stage the control actions of each DG unit will be coordinated at a centralized level (PS level) 17

18 Voltage goes down by effect of Q In order to avoid the trip, PV inverters inject reactive power Q This injection limits the overvoltage within EN limits 18

19 Voltage goes down by effect of Q: not enough. Limits are respected by reducing P If reactive injection is not enough to respect EN 50160, PV inverters can limit active injected power P 19

20 4. Limitation/regulation of active power Under particular network conditions (i.e. temporary limitations to the transit on the distribution network/line; emergency situations on the transmission system) it is necessary to modulate/limit the active power injected by each DG unit In extreme cases, the DG forced shedding is needed. Limitation of active power injected into the network may be implemented: independently, for voltage values close to 110% of Vn (voltage control); automatically, for frequency transients originating in the transmission network; by external command by the DSO. 20

21 The possible set-point values sent by the network operator will be expressed as % of the rated power of the inverter, in steps with a maximum amplitude of 10% Pn. The level of power requested by the setpoint must be reached within 1 minute from receipt of the signal, with a tolerance of ±2.5% Pn. With a set point of 10% Pn, the tolerance must be within the range from 12.5% Pn to 0% Pn, and the inverter will therefore be permitted to disconnect. The signals may be linked to requests by the TSO 21

22 5. Monitoring of DG injections It is possible to collect real time information on the load and on the power generated by DG in the along of the MV network (and, eventually, LV). The amount of generation aggregated by each feeder, transformer, and substation, separated according to technology (PV, wind, biomass, etc) will be available. The Operating Centres of DSO will be able to effectively manage networks with high DG presence, in the perspective of a local dispatch by the DSO. The system will also serve as interface with the TSO in order to provide data for transmission network control, based on: measures taken directly from the DG equipment; a system to receive and aggregate the measures; a huge Data Base to store and elaborate, even temporarily, all data; an interface to access the data from the operators in the control centres; a direct link with TSO control systems to exchange information. 22

23 6. Recharging infrastructure for electric vehicles The Project involves the development of: a recharging infrastructure for electric vehicles (EV); a small photovoltaic plant; a multifunctional storage device. The generation plant, the storage and the recharging structure for EV will be used and coordinated to optimize energy management, load profiles, as well as to provide services to the distribution network PV plant Secondary Substation recharging infrastructure Storage Control system 23

24 7. Enabling demand response strategies through the Smart Info The Smart Info provides each customer with the information about his consumption through a standard and open communication system. The Project aims to make available to 8,000 LV customers information on their energy consumption. Such information is easy to read and to be used to control household appliances. 24

25 Selected smart grid projects INNOVATIVE FUNCTIONALITY P1 P2 P3 P4 P5 P6 P7 P8 Bidirectional communication Participation of generation plants SCADA in PS and on field measurements Automation of the MV grid Participation of DSO to ancillary service market Presence of Storage systems Infrastructure for electrical mobility (test with DSO vehicles) Demand awareness (visual display) Technical solutions of selected projects. 25

26 Benefit score (A j ) A4 A3 A2 A1 REPLICABILITY FEASIBILITY INNOVATION SIZE b1 N. generation plants/storage 6 b2 Increase of electricity production injected into the 12 b3 Increase of ratio "electricity production / electricity 8 b4 N. primary substations involved in the project 4 Max A1 30 b5 Participation of disperse generation to voltage 6 b6 Presence of control system (SCADA) 6 b7 Bidirectional comunication and demand response 6 b8 Presence of storage systems and active power 12 b9 Partecipation of DSO to ancillary service market 10 Max A2 40 b10 Project schedule 4 b11 Quality improvements 6 Max A3 10 % of costs on not regulated subjects (DG and b12 storage) 2 b13 Standard protocols 8 b14 Consistency between investment costs and objectives / expected benefits of the project 10 Max A1 20 Max Project

27 DEVAL Villeneuve prj Aosta region DSO (about customers) Alps area (antonomasia) A lot of communication problems PS VILLENEUVE MVA transformers 49% reverse power flow 11 feeder MV 8 Hydro generators (11,5 MW) TLC UMTS HSPA HSDPA 4G protocol E.CAR Pilot application 27

28 28 FER in Villeneuve

29 Expected benefits Increase of electricity production that can be accepted by the distribution grid in particular from renewable sources or cogeneration voltage and current limits respected DG contribute to system security (wider frequency limits) Innovation in distribution network management Participation of dispersed generation to voltage regulation (today, no reactive power from DG) New resources: storage, EV recharging infrastructure Customer awareness and Demand Response DSO participation at the balancing market Replicability of the pilot projects on a large scale Disclosure of projects and results Ex post regulatory evaluation in order to identify outputs 29

30 (provisional) conclusions Demonstration projects: no only lab, real service Focus on critical situation: MV, high DG penetration (flowmvtohvfor>1%oftime) Requirement: open communication protocols Selection process, KPI approach,evaluators Benefits concept of Psmart Process still ongoing; expected Replicability on large scale Regulatory learning (regulation period ) 30

31 Output vs input incentive regulation Performance based (OUTPUT) incentive regulation Incentive/penalties related to performances Applicable when clear metrics of outputs are available Firms are responsible to choose the most cost effective investment that improves the performance Tariff(INPUT)incentive regulation Useful for pursuing specific types of investments Useful when a grounded metric is not available yet (that is: highly innovative projects) Learningprocessover time (and over space) The learning process started with a research on Hosting Capacity at nodal level on MV distribution network 31

32 Towardsoutput based incentives even for smart grid deployment 32 Indicator Type of network Usability for project assessment Usability for output based regulation Reverse Power Flow Time Distribution (at either network or feeder level) Identifying critical situations due to high RES penetration Filter (together with DG capacity) P smart Distribution (at either network or feeder level) Measure of main smart grid benefit Possibly an output indicator (for incentive) Energy not withdrawn from renewables due to congestion Distribution or Transmission No (ex post indicator) Possibly a disbenefit indicator (for penalty) First regulatory thoughts for SG deployment in IT: DCO 34/11 Further indicators are discussed in the CEER Smart Grid Status Review paper 32

33 Re thinking network regulation BUT how fast is the change? GW installed (provisional data I sem.) 2016 (target) Photovoltaic (mainly in Southern Regions, almost all connected at MV LV level) Wind (mainly in Southern Regions, mostly connected at HV level) Hydro pumping storage (mainly in Northern Region) > > ? 33

34 and how unpredictable is the change? Central Italy Region MARCHE HV/MV TRANSFORMED POWER [MW] 550 MW PV power installed in this region in 1 year (source GSE) 34

35 The role of regulation The level of uncertainty about the future role and direction of networks is unprecedented, at least since privatisation. we think it is important to keep options open wherever possible, to encourage networks to innovate and to ensure the policy and the regulatory frameworks are sufficientlyflexibletoadapttochanges over time Ofgem, LENS Report,

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38 Standardization: a hard step CEN-CENELEC-ETSI

39 Definitvely we have several layer and in order to catch, correctly, the picture we have to manage them all Social Energy Tecnical Environmental Economic 39

40 Outline First of all: what are we talking about? Smart Grid: what are they? Storage: do we really need it? Energy Ecosystem: looking for a solution? 40

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43 Frequency resilience: Interface Protection System issues 43

44 Technical rules are significantly changing Electric Grid Codes start considering the problem: Exponential FV rise Lack of standards The first solutions were only to cope with problems in the short time Then National Regulatory framework move on: Germany MV and HV grid BDEW 2008, LV grid VDE AR N 4105 Italy statrs fromt the LV side (CEI 0 21) and then compelte with MV (CEI 0 16) Spain adapt the technical rules for Wind power plant to PV France, Austria, Switzerland, etc are evaluating all the possible options 44

45 Technical rules: an example Potenza Attiva P/P M [%] Potenza Attiva P M = Potenza Attiva erogata al superamento dei 50,2Hz Germania (VDE AR N 4105) 20 ΔP = 40%*P M /Hz (statismo = 5%) Frequenza (Hz) 50,2 51,5 P/P M [%] ,95 50,05 P M = Potenza Attiva erogata al superamento dei 50,3Hz 5 min Italia (CEI 0 21) P(f) control: Over/under frequency protection managed w.r.t two different thresholds (normal condition vs fault condition) Local and remote capability to select the threshold P reduction in case of overfrequency Limited Frequency Sensitive Mode Overfrequency (LFSM O): P(f) with isteresi (BDEW/TERNA A70/CEI 0 21) continuous P(f) regulation (VDE AR N 4105) droop factor (2% 12%) etc 20 ΔP = 83,3%*P M /Hz 5 min (statismo = 2,4%) Frequenza (Hz) 50,3 51,5 45

46 LVFRT just an example 46

47 Just an example: let s suppose a perturbation Without PV With PV With Smart PV

48 Is it real???? 48

49 A real Black out 49

50 Ancillary Services: grid security and stability Margin to increase Energy Demand Margin to decrease Limited amount of non controllable generation Controllable Power Plant able to provide ancillary services «special» power plans (non controllable) Margin to increase Margin to decrease Controllable Power Plant able to provide ancillary services FV «special» power plants (non controllable Big amount of non controllable generation Demand response Storage capacity Interconnection capacity Back-up capacity RES curtailment Intermittent, non predictible, non controllable 50

51 Economic costs Source: Assessment of the Required Share for a Stable EU Electricity Supply until 2050 ECORYS/ECN Report for DG Energy October

52 ENERGY MODEL: top down or bottom up????? Microgrids An OLD Idea with new possibilities And from Microgrids to VPS 52

53 VPS

54 Are these approaches feasible? Stable? Grids and microgrids, EU IMP 54

55 Do you have any experiences about storage? 55

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57 Outline First of all: what are we talking about? Smart Grid: what are they? Storage: do we really need it? Energy Ecosystem: looking for a solution? 57

58 Energy Ecosystem Actually we are moving from centralized to decentraized energy conversion. Why? Renewables! This evolution will directly impact on the «streets» we are using today (locally ang globally) 58

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60 Pilot Projects in Italy 60

61 Pilot Projects in Italy 61

62 Pilot Projects in Italy 62

63 Pilot Projects in Italy 63

64 Pilot Projects in Italy 64

65 Pilot Projects in Italy 65

66 Pilot Projects in Italy 66

67 Pilot Projects in Germany 67

68 Pilot Projects in Germany 68

69 Energy Ecosystem TRADITIONAL POWER PLANT MAIN GRID HV WIND GENERATOR 100% renewable! Is it possible? BIOGAS DISPERSED ENERGY STORAGE WITH EXTERNAL CONTROL ELECTRIC CARS In which way? INDUSTRIAL LOADS LOCAL GRID LV - MV COMMERCIAL LOADS ELECTRIC CARS DISPERSED ENERGY STORAGE WITH EXTERNAL CONTROL RESIDENTIAL LOADS There isn t any solution, the solution is to have many solutions SOLAR PV 69

70 Ing. Marco Merlo - Politecnico di Milano Department of Energy Electrical Engineering group marco.merlo@polimi.it gine/smartdglab.aspx Grids and microgrids, EU IMP 70