4. Large PV System Jun HAGIHARA Tokyo Electric Power Company – e8 Member Solar PV Design Implementation O&M March 31- April 11, 2008 Marshall Islands Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4. Large PV system • Contents 4-1. Grid Connected (Large PV system) 4-1-1. System Configuration 4-1-2. Type of grid connection 4-1-3. Examples 4-1-4. Distribution NW 4-1-5. Problems on distributed generation 4-1-6. Guide line on distributed generation 4-1-7. Voltage fluctuation by reverse flow 4-1-8. Voltage fluctuation on disconnection 4-1-9. Islanding operation 4-1-10. Detection of islanding operation 4-1-11. Diversity of grid connected generator 2 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4. Large PV system • Contents 4-2. Grid Connected (Hybrid system) 4-2-1. System Configuration 4-2-2. Examples 4-2-3. New components 4-2-4. Planning & design 4-2-5. Check list on planning 4-2-6. One more resource: Energy conservation 3 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4. Large PV system Date Title Sub-title Grid connection Supplied power Size Genset Other RNE Battery system Note April 1 (Tue) SHS DC SHS Off DC < 1kW No No Yes By Mr. Wade AC SHS Off AC < 1kW No No Yes By Mr. Wade April 2 (Wed) Mini grid PV Mini grid Off AC 1 - 50kW No No Yes 50 to 600 Households Battery charge station PV hybrid systems within mini-grid Off AC 10 – 500kW Optional (a few hours per day) Wind biomass micro-hydro etc. Optional New components Grid connected large PV system On AC > 40kW No No Optional With reliable grid (24H supply) Grid connected hybrid system On AC > 100kW Basically No. Optional (a few hours per day) Wind biomass micro-hydro etc. Optional With reliable grid (24H supply) April 3 (Thu) Grid connected Large PV system & Hybrid system 4 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-1-1. Grid connected: Large PV system: System configuration PV panel Inverter PCS Grid-connected Optional battery For a for village (> 40kW) Optional Grid 24 hours power supply by existing generators Battery Delivers the power to the households and common equipments through a grid 5 Marshall Islands March 31-April 11, 2008 4-1-2. Grid connected: Large PV system: Type of grid connection Grid connection - Low voltage - High voltage No islanding operation Reverse flow No reverse flow • Buy power from grid if load > PV output • Sell power to grid if load < PV output • Anytime load > PV output e8 / PPA Solar PV Design Implementation O&M • Reverse power flow relay Islanding operation Reverse flow • On reverse flow, same as above No reverse flow • With battery system, backup power shall be supplied even in power outage Source: NEDO 6 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-1-3. Grid connected: Large PV system: Examples (1) Source: KEPCO • Installed in 2008 at Funafuti, Tuvalu by E8 (KEPCO) • Connected with grid • 40kW PV • Decrease approx. 50t-Co2/y [100 klbs-Co2/y] 7 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-1-3. Grid connected: Large PV system: Examples (2) Source: NEDO • Installed in 2005 at Beijing, China by NEDO (TEPCO+PVTEC) • Office use plus connected with 10kV grid • 140kW PV • Comparison of various kind of PV modules (crystalline, amorphous) 8 e8 / PPA Solar PV Design Implementation O&M Marshall Islands March 31-April 11, 2008 4-1-3. Grid connected: Large PV system: Examples (2) Source: NEDO 9 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-1-3. Grid connected: Large PV system: Examples (3) Source: NEDO • Installed in 2004-2007 at Ohta, Japan by NEDO (Kandenko et al.) • 553 residential houses • Total 140kW PV, connected at 100V with 6.6kV distribution line • Evaluation of the islanding operation protection 10 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-1-3. Grid connected: Large PV system: Examples (3) PV Inverter etc. Load Junction box Source: NEDO • Installed in 2004-2007 at Ohta, Japan by NEDO (Kandenko et al.) • 553 residential houses • Total 140kW PV, connected at 100V with 6.6kV distribution line • Evaluation of the islanding operation protection 11 Marshall Islands March 31-April 11, 2008 4-1-4. Grid connected: Large PV system: Distribution NW Maintain system voltage and frequency anytime. Grid e8 / PPA Solar PV Design Implementation O&M Generator Load Voltage(V) Balance between Generation and load Transmission power and installed capacity Frequency (F) 12 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-1-4. Grid connected: Large PV system: Distribution NW Maintain system voltage and frequency anytime. Grid Distribution substation Feeder 13 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-1-4. Grid connected: Large PV system: Distribution NW Maintain system voltage and frequency anytime. Distribution substation き線イメージ張りつけ 14 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-1-4. Grid connected: Large PV system: Distribution NW Maintain system voltage and frequency anytime. Load Grid power Reverse power flow from distributed generation Load Load G Load Load Power flows from generator to tail end of grid System size suitable to load size 15 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-1-4. Grid connected: Large PV system: Distribution NW Maintain system voltage and frequency anytime. Hard to keep system voltage Distributed generation G Grid × Distribution substation Feeder Disconnected from grid ↓ Hard to keep system frequency 16 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-1-4. Grid connected: Large PV system: Distribution NW Maintain feeder voltage Grid Distribution substation High voltage Low voltage Feeder Control voltage at each bank Voltage Proper voltage Light load Heavy load Distance from substation 17 Marshall Islands March 31-April 11, 2008 4-1-4. Grid connected: Large PV system: Distribution NW Maintain feeder voltage On-load tap-changer at pole transformer Distribution substation Secondary side Primary side High voltage e8 / PPA Solar PV Design Implementation O&M Low voltage Voltage Proper voltage Raise voltage by switching tap-changer Distance from substation 18 Marshall Islands March 31-April 11, 2008 4-1-4. Grid connected: Large PV system: Distribution NW Maintain feeder voltage Distribution substation Control secondary voltage by monitoring current and changing tap of transformer High voltage e8 / PPA Solar PV Design Implementation O&M SVR Low voltage (Step voltage Regulator) Voltage Proper voltage Raise voltage by SVR Distance from substation 19 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-1-4. Grid connected: Large PV system: Distribution NW Maintain feeder voltage Distribution substation Reverse power flow High voltage Low voltage Distributed Generation Voltage Light load Proper voltage Heavy load Deviation from proper voltage Distance from substation 20 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-2-2. Grid connected: Large PV system: Distribution NW Maintain feeder voltage Distribution substation Reverse power flow High voltage Low voltage Can control voltage by monitoring reverse flow from distributed generation, but… Distributed Generation Voltage Light load Heavy load Proper voltage Distance from substation 21 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-1-4. Grid connected: Large PV system: Distribution NW Maintain feeder voltage Disconnectio n Distribution substation High voltage Low voltage Distributed Generation Voltage Proper voltage Deviation from proper voltage Light load Heavy load Distance from substation 22 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-1-4. Grid connected: Large PV system: Distribution NW Earth fault protection of feeder with distributed generation High voltage feeder Generator Without disconnection of distributed generation, earth fault continues even by breaking CB at substation. (Threat of equipment damage and electric shock) Distribution substation It is necessary for distributed generation to be disconnected in concert with the fault detection of system. 23 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-1-5. Grid connected: Large PV system: Problems on distributed generation On grid connection of distributed generation anarchically, the following problems should be investigated. • Power quality • Possibility of harmful effect to other customers via grid • Become harder to operate grid in maintaining power quality and/or maintenance • Safety/security (injury, equipment damage) • Public safety should be assured especially for distribution line ・ which is easily accessible to public. It is necessary to clarify/establish technical rule necessary to orderly dissemination of distributed generation, safety/security, maintaining of reliability and power quality. 24 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-1-6. Grid connected: Large PV system: Guide line on distributed generation Guide line on grid connection • Electrical system of generator • Power factor • Protection relay • Measures for voltage fluctuation • Short circuit capacity • Communication tree on emergency 25 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-1-7. Grid connected: Large PV system: Voltage fluctuation by reverse flow • Reactive power control at power receiving end by generator owner • If not effective, use of exclusive line or reinforcing feeder shall be made by the cost of generator owner. P G Q P G Deviation 26 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-1-8. Grid connected: Large PV system: Voltage fluctuation on disconnection • Automatic load shedding shall be implemented by generator owner G Disconn ection Load increase L Deviation in voltage Voltage G Load shedding Load decrease L Maintain voltage Voltage Deviation Maintain voltage 27 Marshall Islands March 31-April 11, 2008 4-1-9. Grid connected: Large PV system: Islanding operation ① e8 / PPA Solar PV Design Implementation O&M Substation ② ③ CB break ① Crane touches feeder. ② Fault detection, then CB break. ※PV system is running (islanding operation) ③ Threat of electrical shock for worker near crane and public. 28 Marshall Islands March 31-April 11, 2008 4-1-10. Grid connected: Large PV system: Detection of islanding operation Example of detection method • Active detection • Add disturbance signal from generator to grid continuously • On power outage, detect increased response to disturbance signal e8 / PPA Solar PV Design Implementation O&M • Secure detection, but need several seconds • Passive detection • On power outage, detect phase change of P, Q balance • Possible instant detection • But used as backup of active detection for grid connected generator in high voltage, because of little change at rotating generator → Use multiple detection to detect absolutely 29 Marshall Islands March 31-April 11, 2008 4-1-11. Grid connected: Large PV system: Diversity of grid connected generator High voltage Distribution substation L L L Load Load Load G e8 / PPA Solar PV Design Implementation O&M Transformer L G L No reverse Reverse flow flow (G < L) (G > L) Low voltage L L L Load Load Load G L G L No reverse Reverse flow flow (G < L) (G > L) 30 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-2. Grid connected: Hybrid system Date Title Sub-title Grid connection Supplied power Size Genset Other RNE Battery system Note April 1 (Tue) SHS DC SHS Off DC < 1kW No No Yes By Mr. Wade AC SHS Off AC < 1kW No No Yes By Mr. Wade April 2 (Wed) Mini grid PV Mini grid Off AC 1 - 50kW No No Yes 50 to 600 Households Battery charge station PV hybrid systems within mini-grid Off AC 10 – 500kW Optional (a few hours per day) Wind biomass micro-hydro etc. Optional New components Grid connected large PV system On AC > 40kW No No Optional With reliable grid (24H supply) Grid connected hybrid system On AC > 100kW Basically No. Optional (a few hours per day) Wind biomass micro-hydro etc. Optional With reliable grid (24H supply) April 3 (Thu) Grid connected Large PV system & Hybrid system 31 Marshall Islands March 31-April 11, 2008 4-2-1. Grid connected: Hybrid system: System configuration PV panel Wind Biomass e8 / PPA Solar PV Design Implementation O&M Micro-hydro Inverter Genset (runs for only a few hours per day) PCS For a for village (> 100kW) Optional Grid 24 hours power supply by existing generators Battery Grid-connected Optional battery Delivers the power to the households and common equipments through a grid 32 Marshall Islands March 31-April 11, 2008 4-2-2. Grid connected: Hybrid system: Examples (1) Plant Separator Digestive gas supply Digestive gas tank Scarp wood Sludge digester e8 / PPA Solar PV Design Implementation O&M Biomass boiler for woody material (1t/h) School A Gas engine Battery system PV system Steam boiler (existing) School C School B School D Independent line (power & comm.) Total 5.4km PV system Wind power PV system Wind power Buy power from grid Office A Office B Office C PV system Wind power Grid Source: NEDO 33 Marshall Islands March 31-April 11, 2008 4-2-2. Grid connected: Hybrid system: Examples (1) • Installed in 2005 at Hachinohe, Japan by NEDO (Mitsubishi, Hachinohe city) Power receiving panel Woody debris boiler • For schools and city ofiice • Grid connected microgrid • PV: 50kW, 10kW, 2 * 10kW e8 / PPA Solar PV Design Implementation O&M Gas engine Gas tank • Wind: 2 * 2kW, 2 * 8kW • Gas engine: 3 * 170kW Heat/gas pipe Battery system • Battery system: 1,440kWh • Woody debris boiler: 1.0t/h [2.0klbs/h] • Digestion gas boiler: 4.2t/h [8.4klbs/h] Source: NEDO 34 Marshall Islands March 31-April 11, 2008 4-2-2. Grid connected: Hybrid system: Examples (1) GE1 + GE2 GE1 GE1 + GE2 Energy in battery (right axis) Battery PV + Wind Power flow at PCC Demand Control error Load Energy in battery e8 / PPA Solar PV Design Implementation O&M GE1 PV + Wind Battery Power flow at PCC (power purchased) : pink Control error (difference from plan) : red Source: NEDO 35 To use PV widely To improve Power Quality (PQ) Utilization of RE Voltage dip High Quality Peak Shaving Power Supply PS + PQ PV BESS Problems of PV - Sudden output change - Voltage and frequency fluctuation PV output Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-2-2. Grid connected: Hybrid system: Examples (2) : PV+BESS High Quality Power Supply Effective use of PV PV Output Stabilization With BESS Without BESS Time Time 36 Marshall Islands March 31-April 11, 2008 4-2-2. Grid connected: Hybrid system: Examples (2) : PV+BESS High Quality Power Supply PV 80kW Dip Interruption e8 / PPA Solar PV Design Implementation O&M AC433V 力 Grid Max Use TR High Speed SW Normal: closed Abnormal: Opened On Voltage sag, power is supplied by battery. Hi-Tech Farm DC 480V Battery 2000Ah Critical Load PCS 375kVA (Power Conversion System) Mitigate • Voltage Fluctuation • Voltage dip • Momentum interruption • Load Leveling BESS 37 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-2-2. Grid connected: Hybrid system: Examples (2) : PV+BESS High Quality Power Supply PCS (375kVA) - High speed switching - No power interruption PV (80kW) - Roof for parking lot - On rooftop of canteen building Advanced Battery System Remark: Shown equip. capacity is present targeted value. It will be finalized in detail design stage. Cycle-use Lead Acid Battery - Load leveling (100kW, 2.5hr) - PQ protection - EPS (240kW, 10min) 38 Marshall Islands March 31-April 11, 2008 4-2-2. Grid connected: Hybrid system: Examples (2) : PV+BESS High Quality Power Supply New s/s building for battery and elec. equip. e8 / PPA Solar PV Design Implementation O&M PV 70kW Office Parking PV 10kW 39 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-2-3. Grid connected: Hybrid system: New components • NAS battery – Developed by TEPCO and NGK Insulators Ltd. – Cycle-use battery – Suitable for load leveling Safety Tube Installed underground of an amusement park, Tokyo Dome City LaQua. - Peak shaving - Backup power (10%-720kWh) for selected loads Sodium Flow Path Beta Alumina Electrolyte Packed Sand Sodium Electrode Sulfur Electrode Safety tube Beta alumina Electrolyte Cell Case Cell Vacuum Thermal Enclosure (upper) Main Pole Side Heater CELL Fuse Vacuum Thermal Enclosure (lower) 50 kW MODULE 40 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-2-3. Grid connected: Hybrid system: New components • Shin-Kobe Electric Machinery, Co., Ltd – Cycle-use lead acid battery – Stationary VRLA batteries for power storage (LL 1500) – Suitable for load leveling – 1050Ah (25 degree C, 0.23C) – 3,000 cycle (70%DOD) – 10 years lifetime Source: Shin-Kobe Electric Machinery 41 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-2-3. Grid connected: Hybrid system: New components • Kawasaki Heavy Industry – Nickel hydrogen battery – Environment Friendliness (No usage of rare or hazardous material) – Suitable for load leveling Source: Kawasaki Heavy Industries 42 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-2-3. Grid connected: Hybrid system: New components • • • Power systems Co. Ltd. Wellgeo series EDLC (Electrical Double Layer Capacitor) Source: Power systems Co. Ltd. 43 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-2-3. Grid connected: Hybrid system: New components • Advanced PV module – CIS/CIGS (cupper-indium-gallium- serene) – Thin-film PV (4 micro-meter [1.47 * 10-4 inch]) – 125W – Developed by Honda CIGS type Type Crystalline silicon Amorphou s silicon - electrode Buffer CIGS compound CIGS + electrode Energy used in production + electrode Generation cost Conversion efficiency Reliability Si monocrystal type electrod e N Si P Si + electrode Source: Honda Soltec 44 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-2-4. Grid connected: Hybrid system: Planning & design System, equip. spec., supplier, capacity, supply characteristics, reliability, cost and so on. Survey of various REN Concept design of the system Demand characteristics, energy cost, electricity tariff Investigation of target site REN main unit, inverter, grid connection, battery, env. measure Determination of equipment spec. Estimate supplied power and energy • • • Estimate project cost Determine operation pattern Estimate maintenance cost • Estimate total running cost Same as shown in before Economic efficiency is important. Compare generating cost with electricity charge. Investigate optimal (economical) operational pattern Analyze cost/benefit Generation cost, distribution cost, cash flow Effect on environmental protection Effect on energy conservation Implementation 45 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-2-5. Grid connected: Hybrid system: Check list on planning (1) • • • • • Same as shown in before Economic efficiency is important. Compare generating cost with electricity charge. Investigate optimal (economical) operational pattern Concept and purpose – For what? Purposed should be shared among concerned parties. – Where? In existing facility or not? Exact location. – What load? Characteristics and size of load. Enough space for installed equipment? – Which system? Isolated or grid-connected? With battery or not? – When and how much? Construction schedule and cost. Can it be available? 46 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-2-6. Grid connected: Hybrid system: One more resource: Energy conservation Energy management at factory (Japanese case) Submit periodical reports on the use of energy Prepare and submit mid- and long-term plans for measures to achieve energy conservation targets Appoint energy managers Factories/business establishments with high energy consumption (Type 1 Designated Energy Management Factories) Factories/business establishments with medium energy consumption (Type 2 Designated Energy Management Factories) • Annual fuel (thermal) use: 3000 kl [679 kilogallon] in crude oil equivalent or larger • Annual fuel (thermal) use: 1500 kl [339 kilogallon] in crude oil equivalent or larger • Annual electricity use: 12 million kwh or larger • Annual electricity use: 6 million kwh or larger Business Establishments Factories Factories and business establishments Measures Measures Measures • Appointment of Energy Manager (Mandatory to possess a license for a qualified person for energy management of type 1 designated factory) • Preparation & Submission of Periodical Reports • Formulation & Submission of Mid- and long-term Plans • Appointment of a qualified person for energy management of type 2 designated factory (Training Required) • Preparation & Submission of Periodical Reports • Preparation and Submission of mid- and long-term plans (Participation by a qualified person required) • Appointment of a qualified person for energy management of type 2 designated factory • Preparation & Submission of Periodical Reports Business Establishments Factories Department Store Schools Office Building Hotel Source: ECCJ 22 47 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-2-6. Grid connected: Hybrid system: One more resource: Energy conservation Improving Equipment Efficiency (Japanese case) *Top Runner Program: The concept of the program is that fuel economy standards for vehicles and energy conservation standards for electric appliances, etc. shall be set exactly the same as or higher than the best standard value of each product item currently available in the market. Target Example of Top Runner Program Fuel Economy (km/ ) Energy conservation standard based on the Top Runner Program Passenger vehicles (Gasoline and LP gas) Passenger vehicles (diesel) Freight vehicles (gasoline) Freight vehicles (diesel) Air conditioners (cooling & heating) Air conditioners (cooling only) TV sets Videocassette recorders Fluorescent lights Copying machines Computers Magnetic disc units Electric refrigerators/freezers Space heaters Gas cooking appliances Gas water heaters Oil water heaters Electric toilet seats Vending machines Transformers Source: ECCJ 26 Energy conservation effect in comparison with FY2000 (against FY1999 figures for transformers) Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-2-6. Grid connected: Hybrid system: One more resource: Energy conservation Energy-Saving Labeling System (Japanese case) Inform consumers of energy efficiency of home appliances Promote energy-efficient products. Examples of energy-saving labeling Energy conservation standard achievement percentage Energy consumption efficiency Energy conservation standard achievement percentage Energy consumption efficiency Target year FY2005 Target year FY2005 Label for the product's main unit As of April 2005, labeling is applied to the following 13 products: air conditioners, refrigerators, freezers, fluorescent lights, TV sets, space heaters, gas cooking appliances, gas water heaters, oil water heaters, electric toilet seats, computers, magnetic disks, and transformers. Source: ECCJ 27 49 Marshall Islands March 31-April 11, 2008 e8 / PPA Solar PV Design Implementation O&M 4-2-6. Grid connected: Hybrid system: One more resource: Energy conservation Energy-Saving Labeling System (Japanese case) Labeling to be indicated Evaluation Model Number Label Color APF (Annual Energy Efficiency): Key Factor for Labeling Cooling Ranking Manufacture Expected Annual Electricity Bill Achievement Rate Total Consumption in a year (kWh) Heating Name of Product Average COP in Both Cooling and Heating Consumption in Cooling Period (kWh) COP Power Consumption (W) Max. Ave . Min. Class name: Cooling Capacity 3.6 kW and Free Dimension 50 Marshall Islands March 31-April 11, 2008 4-2-6. Grid connected: Hybrid system: One more resource: Energy conservation • Comparison between high efficient Compact Fluorescent Lamp (CFL) and normal Incandescent Lamp bulb e8 / PPA Solar PV Design Implementation O&M Compact Fluorescent Lamp (CFL) Incandescent Bulb 51