Demonstration Project utilizing Hybrid Storage Battery System in the Oki-islands Subsidized project of Ministry of the Environment June 16, 2016 Power System Division The Chugoku Electric Power Co., Inc.
1.Overview of the Oki-Islands 1
Overview of the Oki-islands The Oki-islands are located in the Sea of Japan, about 50km to the north of Shimane Peninsula. Composed of the Dozen and Dogo and about 180 small islands. The total area is about 350km 2. A population is about 21,100 (Dozen: about 6,100, Dogo: about 15,000). Fisheries, agriculture and forestry, tourism are their major industries. 2 Nishinoshima (Nishinoshima) Chiburijima (Chibu) Dozen Nakanoshima (Ama) Dogo Dogo (Okinoshima) Oki-Islands UNESCO Global Geopark September 2013 Certified as Global Geoparks November 2015 Global Geoparks confirmed as UNESCO Global Geoparks The Oki-Islands (Source: Wikipedia, Japan natural location map with side map of the Ryukyu Islands.jpg) Matengai(Nishinoshima) Rousokuiwa(Dogo)
Electrical power supply facilities and demand in the Oki-Islands (Before start of project) 3 2 internal combustion power plants(heavy oil diesel) Saigo and Kuroki, supply almost all the electricity with 22kV tie line. Maximum Power demand is about 24MW,minimum is about 10MW. Dozen Total capacity: 7.38 MW Maximum demand during 2012: 7.3 MW Prefectural Ohmineyama Plant (wind) (Three 600-kW towers for 1.8 MW total) Minamitani Plant (hydroelectric run-of-river) (0.1MW) Kuroki Plant (internal combustion) (7.38 MW) Yui Plant (hydroelectric dam) (0.2 MW) Saigo-Kuroki submarine power cable (22kV,18km) Dogo Dogo Total capacity: 25.32 MW + Wind, Hydro Maximum demand during 2012: 16.8 MW Dozen Saigo Plant (internal combustion) (25.32 MW) Oki Islands Total capacity: 32.70MW + wind, hydro maximum demand during 2012: 24.1 MW
Renewable energy in the Oki-Islands (Before start of the project) 4 wind power plant (1.8 MW) Shimane Prefectural Bureau of Enterprise hydroelectric plant (0.3 MW) The Chugoku Electric Power residential PV (about 0.8 MW) (As of Jan. 2014) Demand Characteristic 22.0 20.0 18.0 (MW) 16.0 Large fluctuations between seasons (Surplus power generation will occur during light-load seasons) Seasonal typical demand-curves in 2012 Spring(May) 春 (5 月 ) 夏 (8 月 ) 秋 (10 月 ) 冬 (1 月 ) Summer(August) Autumn(October) Winter(January) Large-scale introduction of renewable energy used to be difficult 14.0 12.0 10.0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 (Hours)
5 2.Overview of demonstration Project utilizing Hybrid Storage Battery System
Challenges for large renewable energy penetration in the Oki-Islands Short term fluctuation Output fluctuation of RE due to such as transit of cloud Long term fluctuation Output fluctuation of RE due to such as a change in the position of the sun 6 Lack of frequency regulation capacity Surplus power generated Renewable energy output fluctuation MW Increase of Renewable energy Photovoltaic Use of surplus power at night time demand Base-load generation 3 6 9 12 15 18 21 24 Hours
Concept of Hybrid Storage Battery System 7 Countermeasure of short term fluctuation Problem Countermeasure of long term fluctuation Simultaneous solution Lithium ion battery(li-ion) Hybrid Storage Battery System Sodium-sulfur battery(nas) Output Demand curve Increase of Renewable energy [Fast and small fluctuation] ex.)fluctuation by passing cloud Fast and small fluctuation Small capacity and high-output Lithium ion battery(li-ion) Renewable energy (existing) Coordination Base-load generation [Slow and large fluctuation] use PV output at night ex.)fluctuation by locating sun Time Slow and large fluctuation Large capacity Sodium-sulfur battery(nas)
Outline of the Demonstration Project 8 Period : From September 2015 to March 2019 (3.5 years) Items: 1 Coordinated control between storage battery and diesel generation 2 Charge/discharge control technology in order to take full advantage of the storage battery capacity 3 Output allocation of the lithium-ion and the NAS batteries Hybrid Storage Battery System NEW Type Output Capacity 西ノ島変電所西ノ島変電所 NAS 4,200kW 25,200kWh Li-ion 2,000kW 700kWh Nishinoshima substation Hybrid Storage Battery System 6,200kW Kuroki Plant (internal combustion) (7.38 MW) NEW residential PV 500kW Yui Plant (hydroelectric dam) (0.2 MW) Saigo-Kuroki submarine power cable (22kV,18km) Dogo Prefectural Ohmineyama Plant (wind) (Three 600-kW towers for 1.8 MW total) Minamintani Plant (hydroelectric run-of-river) (0.1MW) Dozen NEW Ama Plant(wind) 2,000kW NEW Large-scale PV Plants 3,000kW NEW Large-scale PV Plant 2,000kW Saigo Plant (internal combustion) (25.32 MW)
(MW) Renewable energy introduction plan 9 Aiming at 11MW of total renewable, by newly introducing 8.0MW in addition to the existing 3.0MW, by utilizing the storage battery system. Supply and demand image at the time of the minimum demand Renewable energy facilities Plan MW Record MW As of March 31, 2016 Wind power 1.8 1.8 Storage battery absorb the surplus power generated by renewable energy Renewable energy 11 Before the start of the demonstration project Residential PV About 0.8 About 0.8 Hydroelectric power 0.3 0.3 Subtotal About 3.0 About 3.0 Minimum demand 10 Demand Operational required minimum output of the internal-combustion power Power supply After the start of the demonstration project Large scale PV About 5.0 3.0 Wind power plant 2.0 0.0 Residential PV Total Subtotal About 0.5 About 8.0 About 11.0 About0. 3 About 3.3 About 6.3
Installed facilities and equipments 10 Designed as compact as possible, considering safety measures for NAS characteristics and noise mitigation for neighbor residences. The Nishinoshima substation NAS batteries 4,200kW 25,200kWh Grid-connection equipment Transformers 7,500kVA NaS batteries NaS batteries NaS batteries NaS batteries Gridconnection equipment PCS for NaS batteries Lithium-ion batteries PCS for Lithium-ion batteries Control room Lithium-ion batteries 2,000kW 700kWh Site area:about 2,400 m2
Benefits of hybrid scheme for storage battery system 11 Combination of different types of storage battery system Improvement of charge/discharge management of NAS batteries In hybrid storage battery system, the frequency of SOC reset can be increased by sharing the absorbing capacity for RE output fluctuation between NAS and Li-ion battery, and SOC operational range is possible to expand. Initial cost reduction Combination of Li-ion and NAS battery can decrease construction cost, because /kw of Liion and /kwh of NAS are economical. Improvement of system efficiency Reduction of auxiliary power consumption can be achieved by reducing the capacity of NAS battery, that improves the system efficiency of storage battery system. Cost reduction SOC Operational range (NAS only : SOC reset once a week) Expandable Expandable SOC Operational range (Hybrid storage battery system: SOC reset twice a week) Discharge end Charge end about 30%
Optimal combination of the storage battery capacity 12 Amount of acceptable renewable energy and the required power output and capacity of storage battery system have been determined by simulation. Alternative No. 2 in following table was selected. Alternatives Output [MW] Li-ion Battery NAS Battery Capacity of tie-line Simulation result Charging/Discharging fluctuation Frequency deviation Cost No. 1 1.5 4.8 No. 2 2.0 4.2 No. 3 2.5 3.6 Battery Capacity within the range Battery Capacity within the range NAS Battery Capacity over the range
Hybrid system configuration diagram 13 Li-ion (2,000kW) batteries are composed of 500kW unit 5 set. NAS (4,200kW) batteries are composed of 1,200kW unit 2 set and 1,800kW unit 1 set. Lithium-ion batteries DC/AC Inverter(PCS) 300V Boost transformer DC/AC Inverter(PCS) DC AC The PCS converts between DC and AC as well as protects the facilities from possible malfunctions of the power system. Main transformer Switch gear 290V Breaker transmission lines NaS batteries
14 3.Balancing operation utilizing hybrid Storage Battery System
EMS equipped in Nishinoshima substation performs centralized control through the telecommunication network. - Main function - Forecast of renewable generation and demand Charge/discharge control Mitigation control of short and long term fluctuation Storage Batteries Demand and supply control system - EMS(Energy Management System) Network - Diesel power generation control Wind power generation (new) Legend Photo voltaic generation (new) 15 :Tie line :EMS information :Control system information Nishinoshima substation EMS (main) Kuroki power station EMS (terminal) Prefectural Ohmineyama wind power generation Saigo power station Network EMS (terminal) EMS (terminal) Control system Power Management office Control Center
EMS operation control mechanism 16 By means of unmanned automatic operation, coordinated control between storage battery and internal-combustion power is executed. Short term control Long term control Internal combustion output Frequency Weather Forecast Data Historical Data P+ f Control EMS Renewable generation forecasting Demand forecast Feedback control The short-term control demand Supply and demand plan(long-term control) Supply and demand control(middle-term control) Command the number of operating units and the output Economical load dispatching or Priority List Method Allocation of control demand Li-ion battery Internal combustion NAS Battery
Operational performance of the storage battery 17 Currently, coordinated control performance is generally satisfactory. Example of Coordinated control performance (April 26, 2016) Total demand (MW) Total output of Internal-combustion NAS battery output Lithium ion battery Absorb small fluctuation Total output of Renewable energy Lithium ion battery output 0 NAS battery Discharge the surplus power during the daytime to peak load Frequency management value (upper limit) Frequency (Hz) 60 Frequency management value (lower limit)
18 4.Effect and future prospects by the demonstration project
Expected benefits 19 1Improvement of the power supply stability Introduction of renewable energy and storage battery system improves the stability of power supply in isolated power system 3Activation of the local community Hybrid storage battery is the first challenge in Japan. Expect an increase of visitors 2Reduction of environmental impact By reducing fossil fuel diesel power generation consumption, We can reduce CO2 emissions About 10 thousand tons CO2 reduction per year 4Development and application of new technology Accumulate technical knowledge such as the EMS control logic Contribute to the solution of global challenges Verification being continued aiming further penetration of renewables
Acknowledgements 20 This project was realized with great support of the Ministry of the Environment, through the adoption of the Storage battery demonstration project for promoting the introduction of renewable energy for remote islands, subsidized by the ministry. Also, we have received great cooperation from each municipals of Nishinoshima Town, Oki-Islands, and Shimane Prefecture, in the process of the construction of the substation, and the introduction of renewable energy. We would like to express our sincere appreciation for the efforts of those concerned.
21 Nishinoshima (Nishinoshima) Nakanoshima (Ama) chiburijima (Chibu) Dogo (Okinoshima) <Demonstration project website (Oki hybrid Daisakusen )> http://www.energia.co.jp/okihybrid/index.html