Technical Talk on HK s Largest Solar Power System at Lamma Power Station

Transcription

1 15 June 2011 Technical Talk on HK s Largest Solar Power System at Lamma Power Station for HKIE EV Division by C.K. Lau

2 Agenda Fundamentals of PV Project Background Feasibility Study and Site Selection PV Module Selection System configuration Challenges Project Schedule Initial System Performance Concluding Remarks 2

3 Solar Irradiation vs Global l Energy Resources 3

4 Schematic Diagram of Photovoltaic Cell 4

5 Operating Mechanism of Photovoltaic Cell _ Light Energy Anti-reflection coating electrode N-type Silicon Junction _ External Load P-type Silicon electrode + + Current + 5

6 Typical types of Si Photovoltaic Modules Silicon PV Cell Crystalline Si Cell Thin Film Single-Crystal Si Cell Multicrystalline Si Cell Amorphous Si 6

7 Silicon Crystalline Technology First Generation of PV cells High conversion efficiencies 12-18% High energy inputs which limit significant progress in reducing production costs. Mono crystalline PV Cells Made using saw-cut from single cylindrical crystal of Si Multi Crystalline PV Cells Cast from ingot of melted and recrystallized silicon Cell efficiency up to 18% Cell efficiency up to 16% 7

8 Thin Film Technology Silicon deposited in a continuous on a base material such as glass, metal or polymers Thin-film crystalline solar cell consists of layers about 10μm thick, a- Si thin film solar cells about 1.5 μm thick compared with μm layers for crystalline silicon cells Low cost for fabrication process Strong absorption ability Cell efficiency up to 12% 8

9 Other Thin Film PV Types CIS-based Solar Cell CuInSe2 & CuInGaSe CdTe-based Solar Cell Dye-sensitized Solar Cells Photosensitization of wide band gap semiconductors Organic Solar Cells Low cost & flexible III-V Solar Cells GaAs, InP, GaSb 9

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11 Typical PV installations PV Array on Roof Building Integrated PV Array on ground Concentrated 11

12 Project Background To widen the use of renewable energy in HK Electric s power generation system aiming at achieving better environment and supporting government policy. To explore the introduction of commercial scale solar energy project following the success of commissioning the first commercial scale wind turbine in providing green electricity. 12

13 Lamma Power Station Capacity Coal Fired Units L1-L3: 3 x 250 MW L4-L8: 5 x 350 MW LGO Fired Units GT1 : 1 x 55 MW GT2,3,4 & 6 : 4 x 125 MW Gas Fired Combined Cycle Units GT57 : 1 x 345 MW L9 : 1 x 335 MW Wind Energy Solar Energy Lamma Winds 800 kw TFPV : 550 kw 13

14 Feasibility study and site selection Study and investigation from April to September kW System at EMSD Headquarters 198 kw System at Hong Kong Science Park 14

15 Feasibility study and site selection Hong Kong, a densely populated area, large flat areas at commercial and residential areas and country side of Hong Kong Island for large solar power system are not available Shading and visual intrusion for commercial and residential areas are unavoidable 15

16 Feasibility study Solar Irradiation 180 Irradiation (kwh/m²) Mo onthly Solar JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Month DuPont Not Specified NASA 22-year average ( ) HKO 30-year average ( ) HKO 30-year average ( ) HKO 8-year average ( ) 16

17 Key factors identified for site selection Large flat area for solar PV installation on ground or rooftopthe op total weight of solar panels and supports s against allowable roof loading Orientation of solar panels facing south and tilted at 22º Full utilization of sunlight with no shading Visual impact Ease of grid connectionaccessibility for operation & maintenance Lamma Power Station is selected 17

18 Key factors identified for site selection Lamma Power Station is selected 18

19 Selected locations in Lamma Power Station More than 20 power station buildings/plants have been reviewed. The following roofs of Main Station Buildings is selected. Units 1-3 Boiler House Units 1-6 Bunker Floor & Turbine Hall Units 7&8 Bunker Floor & Turbine Hall Total floor areas is about 35,000 m² Installation of 5,500 PV modules is technically feasible. 19

20 PV Module Selection Thin Film Benefits 1. Use less energy for production The more silicon is used for production of PV panels, the more energy is required. Thin film PV technology uses less silicon. Thickness is only about 1/200 of that for crystalline PV module. 2. More suitable in tropical environment Thin film PV maintains i better power output t level at high temperature than crystalline PV. PV Type a-si thin film PV c-si PV Temp. coefficient for Pm -0.25% per o C increase -0.40% per o C increase 20

21 PV Module Selection Thin Film Benefits 3. Better weak light performance a-si thin film PV modules are able to effectively produce power at low irradiance conditions. 21

22 PV Module Selection Thin Film Benefits 4. Lower cost than c-si The cost of crystalline PV modules is in some degree higher than thin film PV modules. Cost of different PV module technologies 22

23 System Configuration Technical Guidelines HK RE Net References 23

24 System Configuration PV Array 6 PV modules connected in series to form 1 string PV Strings connected in parallel to form PV arrays PV Combiner Box Maximum 20 or 24 PV strings Blocking diode and protection fuse provided for each string AC Power Panel Connection of PV Inverters Isolation Switch PV system isolation Isolation Transformer Direct current isolation PV Inverter 10 kw or 12.5 kw (3-phase) Automatic grid connection Anti-islanding Protection With Maximum Power Point Tracking (MPPT) control AC Metering Panel Main isolation of PV individual System Power Quality Analyzer Major Components 24

25 System Configuration PV STRING COMBINER BOX PV ARRAY 3-PHASE PV INVERTER AC POWER PANEL 2P MCB 3P MCB 3P MCB SIMILAR STRING AS ABOVE 6 MODULES PER STRING PV ARRAY, COMBINER BOX AND INVERTER ARRANGEMENT SAME AS ABOVE 3P MCB 3P MCB MULTI FUNCTION METER EXISTING MAIN DISTRIBUTION BOARD EXISTING MAIN TRANSFORMER 3P MCCB EXISTING LOAD METERING PANEL 3-PHASE 380V 50Hz ISOLATION TRANSFORMER 4P MCCB 3P MCCB 3P MCCB EXISTING LOAD ENERGY & POWER QUALITY METER 4P MCCB Simplified Single Line Diagram 25

26 System Configuration Data Acquisition PV inverters Status Electrical data Local instruments Solar Irradiance Ambient Temperature Module Temperature Power Quality Analyzers Accumulated energy output Electrical data Harmonics Remote Monitoring Computer at Central Control Room of Lamma Power Station 26

27 System Configuration The solar power system will be continuously monitored for verification of system performance Individual Equipment Monitoring PV System Overview Data Acquisition 27

28 System Technical Information Amorphous silicon photovoltaic module 5,500 pieces Total Area of PV modules 8,470 m² Maximum output of each PV module 100 W Total installed Capacity 550 kw Capacity Factor 12.9% Anticipated power output 620, kwh Design life 25 years 28

29 Operation & Maintenance Fully Automatic Operation With solar irradiance of 100 W/m² and the output voltage of PV string at 360V, the system connects to the grid automatically. Simple Maintenance General cleaning required under normal circumstances. Power output not affected even with minor cracks on surface of PV modules. 29

30 Challenges 1. Retrofitting large scale solar power system in existing power plant locating large flat areas without any shade to set up PV modules, while not affecting plant operations. 30

31 Challenges 2. Mounting the PV panels firmly at the selected sites without damaging water-proofing layers on rooftops and wind pressure on PV panels. Typical HK Electric s Solar Power System Mounting Metal of structure fixed modules by anchored bolts Concrete blocks freely stand on the roof to avoid damage to water-proofing layers Wind Pressure 2.4 kpa 5.6 kpa (Stiffeners (No stiffeners) added) 31

32 Challenges Wind Load 32

33 Challenges Wind Load 33

34 Challenges 3. Delivering large quantities of equipment and materials to rooftops. 5,500 Solar Panels 47 PV inverters 47 combiner boxes 25 Electrical and instrument panels 100,000 metres of cables and cable supports 21,888 angle steel brackets for fixing of PV modules onto the concrete blocks 34

35 Challenges 3. Delivering large quantities of equipment and materials to rooftops. 11,000 concrete blocks for fixing of PV modules 250 Ton crane for lifting of materials to roof areas 35

36 Challenges 4. Site work executed on fast track basis to avoiding erection work in hot and humid weather conditions in summer time, rainy and typhoon season in Hong Kong. 36

37 Project Schedule Activities Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Feasibility Study and Site Investigation Supply Tender Detailed Design Election Tender Construction Testing and Commissioning From initial study, the project takes 15 months to complete 37

38 Concluding Remarks Zero emission Reduce 520 tonnes of CO 2 emission per annum Equivalent to planting 22,000 trees Environmental Benefits 38

39 Initial System Performance Irradiance (W / m²) Output (kw) Power Output: 3,582 kwh (Sunny) 1,258 kwh (Cloudy & Rainy) Irradiance (Cloudy & Rainy) Output (Cloudy & Rainy) Irradiance (Sunny) Output (Sunny) :45 6:35 7:25 8:15 9:05 9:55 10:45 11:35 12:25 13:15 14:05 14:55 15:45 16:35 17:25 18:15 19:05 19:55 20:45 Time Power output in response to solar irradiance variation 39

40 Initial System Performance Irradiance (W / m²) Environment Data 1200 Irradiance Temp (ºC) & Current (A) Module Temp Ambient Temp PV Array Current Time Irradiance, PV and Module Temp. captured for performance evaluation 40

41 System Performance (Latest) Electricity Production (kwh) 120, % 110, ,000 90,000 80,000 70,000 60, ,000 40,000 30, ,000 10, % 19.74% 87,965 80,763 Electricity Production since Commissioning 19.55% 17.34% 68, % 17.70% 17.03% 15.38% 62, % 13.75% 57,162 56, % 15.68% 15.14% 11.91% 48, % 10.86% 40,626 44, ,000 kwh anticipated annual electricity production achieved on 5/5/ % 15.65% 15.22% 15.26% 63,342 64,029 Capacity Factor (%) 24.00% 22.00% 20.00% 18.00% 16.00% 14.00% 12.00% 10.00% 8.00% 6.00% 4.00% 2.00% 0 Jul-10 Aug-10 Sep-10 Oct-10 Nov-10 Dec-10 Jan-11 Feb-11 Mar-11 Apr-11 May-11 Jun-11 Month (Forecast) Electricity Production (kwh) Capacity Factor Accumulated Capacity Factor 0.00% 00% 41

42 Concluding Remarks Since commissioned in end June 2010, total electricity output from the PV System up to 15/6/2011 is 710,010 kwh. Capacity factor is 15.3%; well above design capacity factor 12.9%. Electricity generated under cloudy and rainy conditions is about 1/3 of electricity generated under sunny day with strong solar irradiance. The largest solar power system in Hong Kong. The first large scale solar power project applying amorphous silicon thin film technology. The long term target is to expand the total capacity to 1 MW. 42

43 Lamma Power Station 550kW Solar Power System 43

44 Thank You