CSR Charter ⅡHarmonizing with the Environment and Contributing to Realizing a Sustainable Society
Actions for Climate Change: Working to Reduce CO2 Emissions in Business Activities
- Principle and Outline
- Benefits of Energy Saving and Reductions of CO2 Emissions
- GHG Emissions at Daigas Group
- Efforts by the Daigas Group to Reduce CO2 Emissions from City Gas Business
- Efforts to Reduce CO2 Emissions from Electricity Business
- TOPIC: The Establishment of the Green Power Fuel Corporation
Principle and Outline
In view of the worldwide trend to combat climate change, the Daigas Group is working on reducing emissions of greenhouse gases generated through our business activities, such as CO2 and methane (CH4), in order to help bring about a low-carbon society. Specifically, we are reducing CO2 emissions when transporting liquefied natural gas (LNG), when manufacturing city gas and when generating electricity. We are also taking various company-wide steps to promote energy saving in business offices while verifying whether our energy-saving efforts have produced the intended results in our own buildings.
Benefits of Energy Saving and Reductions of CO2 Emissions
Reduction of 2.2 million tons of CO2 emissions in Group business activities
The Daigas Group has been introducing cryogenic power generation facilities for city gas processing, high-efficiency thermal power generation, and renewable energy sources (solar, wind, biomass, etc.). These business activities have contributed to a reduction in emissions of approximately 2.2 million tons in FY2019.
GHG Emissions at Daigas Group
Initiatives to reduce CO2 emissions from energy consumption and methane (CH4) emission
In the Daigas Group, we work to reduce CO2 emissions from energy consumption and methane (CH4), the main component of natural gas in the gas business and in the thermal supply and power generation businesses, as well as CO2 emissions from energy consumption at affiliates.*
- * Affiliated Companies
- Of Osaka Gas's 150 consolidated subsidiaries, 56 companies are subject to the calculation of GHG emissions. Those housed in office buildings as tenants and whose environmental data are difficult to grasp and whose environmental effects are minimal are not subject to such calculation. Also excluded from the calculation are overseas companies whose environmental impacts are minimal. However, the aggregate number of companies may differ by fiscal year and by item due to company mergers and others.
(As of March 31, 2019)
Group companies No. of
Company names Energy Resources & International Business Unit 1 Michigan Power Limited Partnership LNG Power & Engineering Business Unit 16 Gas and Power Co., Ltd., Nakayama Joint Power Generation Co., Ltd., Nakayama Nagoya Joint Power Generation Co., Ltd., Hirogawa Myojinyama Wind Farm Co., Hayama Wind Farm, Yura Wind Farm Development, Hizen Wind Farm, Hirao Wind Farm, Inami Wind Power Plant, Senboku Natural Gas Power Generation, Osaka Gas Liquid Co., Ltd., Cold Air Products Co. Ltd., Cryo-Air Co. Ltd., Kinki Carbonic Co., Ltd., Gasnet Co. Ltd., Osaka Gas Engineering Co., Ltd. Pipeline Business Unit 2 Kinpai Co., Ltd., Osaka Gas Renotech Co., Ltd. Residential Energy Business Unit 9 Living Maintenance Service Hokuto Co., Ltd., Living Maintenance Service Osaka Co., Ltd., Osaka Gas Cooking School Co., Ltd., Create Kansai Co., Ltd., Osaka Gas Customer Relations Co., Ltd., Aqua Brain Co., Ltd., Kansai Business Information Inc., Osaka Gas Housing & Equipment Co., Ltd., Osaka Gas Security Service Co., Ltd. Commercial & Industrial Energy Business Unit 8 OGCTS Co., Ltd., Ashiyahama Energy Service Co., Ltd., Rokko Island Energ Service Co., Ltd., Enetec Kyoto Co., Ltd., Enetec Osaka Co., Ltd., Nabari Kintetsu Gas Co., Ltd., Toyooka Energy Co., Ltd., Shingu Gas Ltd. Group Headquarters 6 OG Sports Co., Ltd., Osaka Gas Autoservice Co., Ltd., Osaka Gas Finance Co., Ltd., Osaka Gas Business Create Co., Ltd., Active Life Inc., KRI Inc. Osaka Gas Urban Development Group 3 Osaka Gas Urban Development Co., Ltd., Osaka Gas Facilities Corp., Kyoto Research Park Co., Ltd., OGIS Research Institute Group 7 OGIS-RI Co., Ltd., Agnie Consulting Corp., Sakura Information Systems Co., Ltd., SIS Techno-Service Co., Ltd., JOE Corp., Ltd., Ube Information Systems Inc., System Answer Inc. Osaka Gas Chemicals Group 4 Osaka Gas Chemicals Co., Ltd., Minabe Chemical Industries Ltd., Mizusawa Industrial Chemicals, Ltd., Mizuka Unyu Co., Ltd. Total 56
GHG Emissions* (1,000 t-CO2e)
|Consolidated companies (Osaka Gas and its affiliates)||74||69||65||58||57|
|District heating / cooling||12||11||11||10||9|
|District heating / cooling||112||107||108||104||97|
- * GHG emissions
- [CO2 emissions]
CO2 emissions calculated using the average emission factor for thermal power source are subject to management in the Daigas Group so that the benefit of reducing the consumption of purchased electricity can be properly evaluated.
CO2 emissions for FY2017 were calculated using the average emission factor of 0.65 t-CO2 / 1,000 kWh, a figure decided under a government plan to combat global warming, approved by the Cabinet in 2016. CO2 emissions through FY2016 were calculated using the factor of 0.69 t-CO2 / 1,000 kWh, a figure shown in an Interim Summary Report compiled in 2001 by the Target Attainment Scenario Subcommittee under the Global Environmental Committee of the Central Environmental Council.
CH4 emission is calculated using the global warming factor of 25, defined in the UNFCCC reporting guidelines on annual greenhouse gas inventories published in 2012. Greenhouse gas emissions are defined as the aggregate of CO2 emissions and CO2 equivalent of CH4 emissions.
(Reference) GHG Emissions for Comparison* (1,000 t-CO2e)
|District heating / coolings||11||10||10||9||9|
|District heating / cooling||103||97||98||94||86|
- * GHG emissions for comparison
- For calculation of the yearly CO2 emissions of purchased electricity, the most recent emission factor of the Kansai Electric Power Co., Inc. is used. (e.g. The CO2 emission factor of FY2015 is calculated based on the emissions during FY2014) CO2 emissions of FY2016 and after are calculated using emission factors of electric companies from which we purchased electricity. The yearly CO2 emissions of purchased electricity is calculated by multiplying the year's electricity consumption by the year's emission factor.
CO2 emissions from Osaka Gas's city gas business * Not subject to third-party verification
CO2 emissions in Osaka Gas’s city gas business for FY2019 stood at 128,000 tons, with CO2 emissions per cubic meter of gas production (emissions intensity) of 15.7 g-CO2/m³. Compared to 1990, the Kyoto Protocol’s benchmark year, total CO2 emissions were down by 52%, and emissions on a per-unit basis fell by 73%.
Efforts in recent years, such as the use of cogeneration systems and cryogenic power generation at city gas processing plants, energy efficient operations, and efforts to conserve energy in office buildings have succeeded in keeping both emissions and intensity at low levels. In FY2019, CO2 emissions and intensity increased from the previous fiscal year due to the impact of partial line stoppages caused by construction work at processing facilities.
In 1979, Osaka Gas became the first company in the world to begin operating a cryogenic power generation facility, and in FY2019 the Senboku LNG Terminal and the Himeji LNG Terminal produced approximately 75.00 million kWh cryogenically.
We will work toward further CO2 emission reductions by aggressively using electricity produced by unused energy such as LNG cryogenics and the gas pressure of gasification, as well as by promoting energy savings in office buildings.
CO2 Emissions from the City Gas Business of Osaka Gas
Methane emissions from Osaka Gas's city gas business
In the city gas business of Osaka Gas, methane (CH4) gas is emitted during measurement of gas quality and gas fitting work. We therefore strive to reduce emissions by introducing a system that can recollect gas without it being released into the air after the measurement, by employing a no-blow gas shutting-off method and using an Eco Purge vehicle.
Methane gas emissions were 88 tons in FY2019, indicating that the downtrend remains intact.
Methane Emissions at Osaka Gas
|Methane emission (t-CH4)||94||92||75||77||88|
CO2 emissions from affiliates
CO2 emissions from affiliate companies amounted to about 5.1 million tons in FY2019. Most of the total comprised CO2 emitted at fossil-based power stations. The Daigas Group is striving to curb CO2 emissions from its business operations and at the same time achieve energy savings by combining the operation of energy-efficient fossil-derived power stations with the use of renewable energy sources.
Efforts by the Daigas Group to Reduce CO2 Emissions from City Gas Business
Efforts to reduce CO2 emissions in LNG transportation
In November 2018, Osaka Gas put the fuel-efficient LNG JUNO into service for the transport of LNG, an essential material for city gas. Osaka Gas adopted the new Sayaringo type of LNG carrier, which was instrumental in increasing LNG capacity without changing the width of the vessel. The carrier also adopted a new hybrid propulsion system, further reducing fuel consumption and lowering CO2 emissions and transport costs.
Efforts to reduce CO2 emissions at city gas processing terminals
We are endeavoring through a variety of energy conservation activities to reduce CO2 emissions at city gas processing terminals.
We are endeavoring to reduce CO2 emissions at city gas processing terminals through a variety of energy conservation activities.
One example is the reduction of purchased electricity achieved by recovering the kinetic energy from LNG regasification and using it for power generation. This is cryogenic power—LNG cryogenics—a system that generates power without fuel and produces zero CO2 emissions. A cryogenic power generation facility was newly put into operation at the Himeji LNG Terminal in March 2017.
The Group is also putting in place various policies to ensure the efficient operation of LNG cryogenic power generation facilities. Cold energy from LNG is supplied to a chemical plant adjacent to the Senboku Terminal for their cooling processes, also helping other companies in the vicinity to save energy and reduce CO2 emissions.
Reducing CO2 emissions at offices
At offices of each company of the Daigas Group, many small steps are being taken to save energy that will add up for achieving energy consumption and CO2 emissions targets. These include having all employees turn off lights that are not needed, switching off office equipment if not in use, and maintaining air conditioning temperatures at reasonable levels. The effort is based on standards such as ISO 14001, Eco Action 21, developed by the Ministry of Environment, and the Daigas Group Environmental Management System (OGEMS).
Under the EMS, each and every employee strives to reduce his or her own energy consumption by turning off lights and office equipment not currently needed or in use, and setting air conditioning to reasonable temperatures in line with set targets.
The Daigas Group has actively been implementing advanced energy-conservation measures and measures to reduce CO2 emissions when its buildings are renewed or renovated. Measures deemed effective for energy saving are horizontally applied to all office buildings of the Daigas Group under the “Green Gas Buildings” project. As of August 2018, the “Green Gas Buildings” project is applied at nine of the Group's business offices.
When we renovated the Hokubu Gas Building (Takatsuki City, Osaka Prefecture), Osaka Gas incorporated the “Behavioral Observation Method” *1 into the building design process to further promote energy saving. Observation and analysis of the tenants' behavior on energy saving according to the method allowed us to realize reduction of CO2 emissions.
Our offices also introduced monitoring systems such as the “Motto Save,” which is aimed at promoting energy saving at office buildings by deciding their optimal energy use based on building size and the type of building operation. In addition, the Fukiai office of Osaka Gas, located in Kobe City, Hyogo Prefecture, introduced “BCP-Lite,” *2 an emergency power-supply system that enables even a small-sized building not usually equipped with a backup power generator to continue the minimum level of business operations in the event of a natural disaster. The “BCP-Lite” is a system in which the concept of a Business continuity plan (BCP) was added to our conventional energy-saving equipment. We expect this to help the building of a low-carbon society in the future while supporting our business continuity in the event of a contingency.
The “hu+gMUSEUM,” a showroom of Osaka Gas, is equipped with facilities with high energy efficiency, including cogeneration systems, regional air-conditioning systems, solar power generation systems, and solar-heat systems. Furthermore, the Group has built a Smart Energy Network in Osaka City's Iwasaki District where the showroom is situated. The network has played an important role in promoting the region's overall energy saving by establishing an optimal energy control system to ensure the most efficient use of energy (electricity and heat) generated in buildings and devising a high energy security system that can effectively respond to unscheduled power outage.
The Daigas Group received the “Building Energy-efficiency Labeling System (BELS)” *3 assessment for two of its properties in FY 2017. The most recently constructed buildings of the Fukiai Office and the hu+gMUSEUM received four stars and five stars, respectively, under the five-star BELS system for their excellent energy conservation performance. Their respective energy-conservation rates in the year were a high 33% and 39%.
Osaka Gas received the 2018 technology promotion award from the Society of Heating, Air-Conditioning and Sanitary Engineers of Japan for its contribution to local communities and concretization of an advanced energy system through its hu+gMUSEUM showroom, which was recognized as the utility's new information dissemination base.
- *1 “Behavioral observation”
- “Behavioral observation” is a methodology for identifying and presenting solutions based on the academic analysis of facts and findings obtained through the observation of people's behavior.
- “BCP-Lite” is an emergency power supply system for office buildings in which electricity can be supplied without interruption even if power outage occurs following a natural disaster. A self-driven gas engine heat pump (GHP) is incorporated into the system.
- BELS stands for “Building Energy-efficiency Labeling System.” The labeling system for buildings and housing is aimed at evaluating the energy-saving ability of nonresidential buildings based on the Act on Improvement of the Energy Consumption Performance of Buildings. The evaluation, certified by third parties, is given on a scale of one to five stars. The evaluation result is represented by a number of stars displayed on a special plate.
Smart Energy Network
Osaka Gas structured a district heating and cooling system at the area surrounding the facilities of the Company in Nishi Ward in Osaka City. The system also functions as the Smart Energy Network, where heat and electricity generated in the area are accommodated in the community. The system can be controlled optimally from the perspective of the entire area, realizing an approach to urban planning that allows energy to be used efficiently.
Efforts to reduce CO2 emissions through district heating and cooling systems
District heating and cooling systems are designed to promote efficient use of energy sources by having people and offices in the same area use energy systems such as air conditioners, heaters and hot-water supply equipment together. In the case of the Daigas Group, such systems were first introduced in Japan in 1970 in the Senri Chuo district of Toyonaka City, Osaka Prefecture. Since then, various energy systems have been adopted by the group in various regions in Japan, each system developed in an optimal manner to reflect each region's needs under its urban development project. The Daigas Group introduced such systems in totaling 10 districts in Osaka, Kyoto, Nara and Kobe. The Daigas Group was ahead of other companies in introducing gas cogeneration systems under the framework of regional-based air-conditioning and heating systems. The group has been also active in starting new businesses, such as accepting waste heat generated under cogeneration systems run by customers and supplying electricity to certain customers as a registered Specified Electricity Utility.
The Daigas Group has been also working to secure stable heat supplies, promoting the advanced use of energy, increasing efficiency in administrative management and cutting business costs. More recently, the group built a Smart Energy Network in Osaka City, which is an energy network system focusing on the utilization of natural gas cogeneration and renewable energy sources. All these measures represent the Daigas Group's efforts to promote both energy conservation and energy security.
The Daigas Group is redoubling its efforts to further increase energy system efficiency by introducing high-efficiency equipment in conjunction with the renewal of facilities Kobe and Senri district.
Efforts to Reduce CO2 Emissions from Electricity Business
The Daigas Group engages in the electricity generation business using various power sources it owns, including fossil-based power generation, gas cogeneration systems and renewable energy sources. The Daigas Group is striving to reduce CO2 emissions—not only from its own business operations but also from operations at customers—by introducing highly energy-efficient fossil-based power generation systems and actively using renewable energy sources.
Power Generation Facilities Operated by the Daigas Group (domestic facilities for power generation)
(As of March 31, 2019)
|Name of project||Location||Power
|Natural gas-based power generation|
|Senboku Terminal (No. 1 Plant)||Sakai City, Osaka Prefecture||20,000 kW||GTCC*1 and others||July 2002|
|Senboku Natural Gas Power Generation Co., Ltd.
Senboku Natural Gas Power Plant
(Unit 1, Unit 2: No. 2 Plant of Senboku Terminal)
(Unit 3, Unit 4: No. 1 Plant of Senboku Terminal)
Unit 1, Unit 2: Takaishi City
Unit 3, Unit 4: Sakai City
|Unit 1, Unit 2: 277,000 kW x 2
Unit 3, Unit 4: 277,500 kW
Total 1,109,000 kW x 2
|GTCC||April 2009 (Unit 2)
May 2009 (Unit 1)
Oct 2009 (Unit 4)
Nov 2009 (Unit 3)
|Himeji Terminal||Himeji City, Hyogo Prefecture||66,000 kW||GTCC and others||April 2004|
|Nakayama Joint Power Generation Co., Ltd. Funamachi Power Plant||Taisho Ward, Osaka City||149,000 kW*2||GTCC||April 1999|
|Gas and Power Co., Ltd. Torishima Energy Center||Konohana Ward, Osaka City||141,000 kW||GTCC||April 2002|
|Gas and Power Co., Ltd.
Uji Energy Center
|Uji City, Kyoto Prefecture||67,000 kW||GTCC||October 2004|
|Gas and Power Co., Ltd. Settsu Energy Center||Settsu City, Osaka Prefecture||17,000 kW||Gas engine||April 2006|
|OGCTS Co., Ltd.
Senri Energy Center
|Toyonaka City, Osaka Prefecture||7,000 kW||Gas turbine||January 2008|
|Biomass-fired and coal-fired power generation|
|Nakayama Nagoya Joint Power Generation Co., Ltd. Nagoya Power Plant||Chita County, Aichi Prefecture||149,000 kW*2||Coal steam turbine, biomass (5%)||April 2000|
|Nakayama Nagoya Joint Power Generation Co., Ltd.
Nagoya No. 2 Power Plant
|Chita County, Aichi Prefecture||110,000 kW*2||Coal steam turbine, biomass (30%)||September 2017|
|Biomass power generation|
|Biomass Power Technologies Inc.
Matsusaka Woody Biomass Power Plant
|Matsusaka City, Mie Prefecture||2,000 kW*3||Exclusively for biomass burning, direct burning plant (air-cooling method)||January 2018|
|Hayama Wind Power Generation Co.
Hayama Wind Farm
|Takaoka County, Kochi Prefecture||20,000 kW||Wind power (1,000 kW x 20 units)||March 2006|
|Hirogawa Myojinyama Wind Farm Co., Ltd.
Hirogawa Myojinyama Wind Farm
|Arida County, Wakayama Prefecture Hidaka County, Wakayama Prefecture||16,000 kW||Wind power (1,000 kW x 16 units)||November 2008|
|Yura Wind Development Co. Yura Wind Power Plant||Hidaka County, Wakayama Prefecture||10,000 kW||Wind power (2,000 kW x 5 units)||September 2011|
|Hizen Wind Power Generation Co., Ltd.
Hizen Wind Farm
|Karatsu City, Saga Prefecture||12,000 kW||Wind power (1,500 kW x 8 units)||March 2005|
|Hizen Wind Power Generation Co., Ltd.
Hizen Minami Wind Farm
|Karatsu City, Saga Prefecture||18,000 kW||Wind power (1,500 kW x 12 units)||January 2008|
|Hirao Wind Development Co. Hirao Wind Power Plant||Kumage County, Yamaguchi Prefecture||9,000 kW*4||Wind power (1,500 kW x 6)||April 2009|
|Inami Wind Power Station Co. Inami Wind Power Station||Hidaka County, Wakayama Prefecture||26,000 kW*2||Wind power (2,000 kW x 13 units)||June 2018|
|Solar power generation and others|
|Gas and Power Co., Ltd.
Torishima Solar Power Plant
|Konohana Ward, Osaka City||1,800 kW*5||Solar power||April 2013|
|Gas and Power Co., Ltd. Torishima Second Solar Power Plant||Konohana Ward, Osaka City||1,200 kW*5||Solar power||January 2014|
|Gas and Power Co., Ltd.
Shoo Solar Power Plant
|Katsuta County, Okayama Prefecture||900 kW*5||Solar power||April 2013|
|Hirogawa Myojinyama Wind Farm Co., Ltd.
Hirogawa Myojinyama Wind Farm
|Arida County, Wakayama Prefecture||800 kW*5||Solar power||April 2013|
|Yura Wind Development Co.
Yura Solar Power Plants (North and South)
|Hidaka County, Wakayama Prefecture||1,700 kW*5||Solar power||December 2016|
|Nabari Kintetsu Gas Co., Ltd.
Yahata Solar Power Plant
|Nabari City, Mie Prefecture||700 kW*5||Solar power||September 2013|
|JGC Mirai Solar Co., Ltd. NISSAN Green Energy Farm in Oita||Oita City, Oita Prefecture||26,500 kW*5*6||Solar power||May 2013|
|OGCTS Co., Ltd.||6 plants||7,800 kW *5||Solar power and others|
|Energy Bank Japan Co., Ltd.||25 plants||35,300 kW *5||Solar power and others|
|Total domestic power generation capacity for electricity business||2,009,500 kW*7|
- *1 GTCC
- Gas turbine combined-cycle power generation method
- Output capacity owned by our company: 95%
- Output capacity owned by our company: 14.5%
- Output capacity owned by our company: 99.8%
- Output capacity for solar power is measured in terms of solar power panels.
- Output capacity owned by our company: 49%
- Output capacity listed as ownership of our company in NISSAN Green Energy Farm in Oita, operated by JGC Mirai Solar Co., Ltd., is 13,000 kW and output capacity listed as ownership of our company in Matsusaka Woody Biomass Power Plant, operated by Biomass Power Technologies Inc., is 300 kW.
Overview of Senboku Natural Gas Power Plant
Environment-friendly Senboku Natural Gas Power Plant operating smoothly
In FY2010, Osaka Gas's natural gas power plant at the Senboku Natural Gas Power Plant, a core part of our power generation business, went into operation, with four turbines working at a total capacity of 1.109 million kW. The Senboku Natural Gas Power Plant uses natural gas for power generation, creating far less impact on the environment than using other fossil fuels such as oil and coal. Other features make this plant a cutting-edge facility with minimal environmental impact; for example, the use of the gas turbine combined cycle method, which has a high energy efficiency.
Adoption of a gas turbine combined-cycle power generation method
Under the gas turbine combined-cycle power generation system, natural gas is combusted in the gas turbine's combustor, and the combusted gas then turns the gas turbine to generate electricity. In addition, the heat of the gas turbine's exhaust gas creates steam in an exhaust heat recovery boiler that turns a steam turbine to generate electricity. This gas turbine combined-cycle power generation is thus able to attain high efficiency in producing power by recycling the heat of exhaust gas.
The Senboku Natural Gas Power Plant uses a 1,300℃-class gas turbine to achieve a high power generation rate of about 57% (Lower heating value (LHV) standard), helping conserve energy and reducing CO2 emissions.
Environmental assessment procedures are currently underway in line with the Environmental Impact Assessment Act for a new natural gas-based power generation project, tentatively called “Himeji Natural Gas Power Plant Project,” undertaken by Himeji Natural Gas Generation Co., a joint company between Osaka Gas and Idemitsu Kosan Co. The project plans to introduce the highly energy efficient gas turbine-combined cycle method.
Energy Efficiency of Gas Turbine Combined-Cycle Power Generation
Preventing air pollution
Because the Senboku Natural Gas Power Plant uses natural gas, its exhaust gas contains no sulfur oxides (SOx) or soot and dust. Although nitrogen oxides (NOx) are generated by the combustion of natural gas, they are minimized by the use of a low NOx burner, and those that are generated are further reduced by an exhaust NOx removal system.
|Power generation system
Gas turbine combined cycle power generation
|Generating capacity||(Senboku LNG terminal Ⅱ)||(Senboku LNG terminal Ⅰ)|
|No. 1 turbine: 277,000 kW||No. 3 turbine: 277,500 kW|
|No. 2 turbine: 277,000 kW||No. 4 turbine: 277,500 kW|
|Total: 554,000 kW||Total: 555,000 kW|
|Environmental protection measures||Low NOx burner, ammonia-based exhaust NOx removal system, discharged water processing system, etc.|
Plant System Flowchart
● Use of existing infrastructure
The need for new facilities for the plant is being minimized by locating the plant on the site of the Senboku LNG Terminal, which is equipped with an infrastructure that includes fuel supply facilities.
● Remote operational surveillance system
Stable operation of the plant by a small workforce is achieved by development of an integrated operational monitoring system for controlling power generating facilities spanning two sites.
Use of natural gas (LNG) as the fuel for generating electricity means that no SOx or soot and dust are generated.
The latest low NOx burners are used to reduce NOx emissions.
● Inlet air cooling system
Gas turbine intake air is cooled to limit the reduction in power output at high temperatures.
Flue height is increased to reduce ground-level concentrations of NOx.
● NOx removal system
Inside the waste heat recovery boiler is an exhaust NOx removal system, which uses the dry ammonia catalytic reduction method to break the NOx content of combustion gas down into water and nitrogen and reduce the concentration of NOx in the exhaust gas.
● Cooling towers
No warm wastewater is discharged due to the use of a cooling tower system.
● Wastewater treatment system
Wastewater from the power plant is treated by a wastewater treatment system comprising coagulation sedimentation, filtration, activated carbon adsorption, and pH adjustment to reduce the impact on water systems.
Overview of Nagoya Power Plant and Second Nagoya Power Plant
Smooth operation of Nagoya Power Plant and Second Nagoya Power Plant contributes to the reduction of environmental impacts.
Nagoya Power Plant (capacity: 149,000 kW) and Second Nagoya Power Plant (capacity: 110,000 kW) use mixed fuel, coal and woody biomass, to substantially reduce CO2 emissions. The plants are also equipped with the latest environmental conservation technology to reduce hazardous substances and noise.
Biomass-combined coal-fired power generation
Nakayama Nagoya Joint Power Generation Co., Ltd., a Daigas Group company, has adopted a biomass-combined coal-fired power generation method at the Nagoya Power Plant (coal-fired plant) and the Second Nagoya Power Plant (coal-fired plant) to curb CO2 emissions. The method uses woody biomass in the base fuel of coal.
The fuel used at the Nagoya Power Plant (with a total output capacity of 149,000 kW) contains 5% woody biomass. The rate of woody biomass stands at 30% for the fuel used at the Second Nagoya Power Plant (with a total output capacity of 110,000 kW). The plants are operated jointly with the aim of increasing operational efficiency in power generation and coal transportation.
Preventing air pollution
The boilers at Nagoya Power Plant and Second Nagoya Power Plant are equipped with various flue-gas purifiers, such as a low NOx burner and denitration system to reduce NOx generation, an electrostatic precipitator to eliminate dust, and a desulfurizer system to reduce sulfur emissions.
|Nagoya Power Plant||Second Nagoya Power Plant|
|Power generation system||Steam-power generation (using pulverized coal and subcritical pressure)||Steam-power generation (using pulverized coal and subcritical pressure)|
|Generating capacity||149,000 kW||110,000 kW|
|Fuel||Coal, woody biomass (5% mixture in energy ratio), and kerosene (auxiliary fuel)||Coal, woody biomass (30% mixture in energy ratio), and kerosene (auxiliary fuel)|
|Environmental protection measures||Low NOx burner, ammonia-based exhaust NOx removal system, electrostatic precipitator, flue-gas desulfurizer system using limestone-gypsum method, etc.||Low NOx burner, ammonia-based exhaust NOx removal system, electrostatic precipitator, flue-gas desulfurizer system using limestone-gypsum method, etc.|
|Cooling system||Cooling system using sea water||Cooling system using industrial water|
System Flow of Second Nagoya Power Plant
Woody biomass is mixed with the base coal fuel to reduce CO2 emissions.
● NOx removal system
A flue-gas denitration system (using dry ammonia catalytic reduction method) is installed after the boiler to decompose NOx contained in exhaust gas to water and nitrogen and reduce the NOx concentration in flue gas.
● Electrostatic precipitator
An electrostatic precipitator is installed after the denitration system to eliminate dust in combustion gas.
● Desulfurizer system
A desulfurizer system (limestone-gypsum method) is installed after the electrostatic precipitator to eliminate sulfur emissions in combustion gas. Sulfur is recovered as a form of gypsum to be effectively recycled.
Introduction of Cogeneration-Based Electricity Sources
Energy-efficient natural gas cogeneration facilities are set up on the premises of a client plant. Electricity and heat (steam) generated using the cogeneration system are provided to client companies. The Daigas Group uses part of the electricity generated as electricity sources for its power business, which helps improve the cogeneration facility utilization rate, promotes efficient energy use and reduces CO2 emissions. Gas and Power Co., an Osaka Gas Group company, operates this type of facility at two locations—one at the Uji Energy Center for Unitika Ltd. and the other at the Settsu Energy Center for Kaneka Corp. Power output capacity is 66,800 kW at the Uji Energy Center and 17,460 kW at the Settsu Energy Center.
Efforts to Spread Renewable Energy Sources
The Daigas Group has contributed to reducing CO2 emissions by operating power facilities in Japan using renewable energy sources, such as wind power, solar power and biomass, with a combined output capacity of about 210,000 kW. In Wakayama Prefecture, Inami Wind Power Station Co. began operating the Inami Wind Power Station, a power plant with an output capacity of 26,000 kW, in June 2018.
In FY2019, the Group announced to build two 75,000 kW biomass-fired power generation plants, the largest of their kind in Japan, in Sodegaura, Chiba Prefecture, and Himeji, Hyogo Prefecture, as part of efforts to further expand electricity generation from renewable energy sources.
The Establishment of the Green Power Fuel Corporation
Osaka Gas Co., Ltd. established Green Power Fuel Corporation in March 2019 as a joint venture with Seishin Shinrin Shigen Co., Ltd. and Nippon Paper Lumber Co., Ltd. to procure and sell domestically grown woody biomass for biomass power plants.
The Daigas Group is planning and operates a number of biomass power plants in Japan, including its participation in the Matsusaka Woody Biomass Power Plant, which is fueled 100% with locally available biomass. In cooperation with Seishin Shinrin Shigen, which has abundant knowledge about the wood industry, and Nippon Paper Lumber, which has a long track record in domestically grown woody biomass, Green Power Fuel will procure and transport leftover, unusable timber from domestic woodlands as fuel for biomass power generation to supply stably to multiple biomass power plants owned or developed by the Daigas Group over the long term.
In the future, the Daigas Group is also studying the possibility of sales to other power generation operators, aiming to consistently expand the business by utilizing the three companies’ strengths.
International power projects
Our international IPP business includes investment in fossil-based power plants, wind power projects and solar power projects in North America and Australia. In 2017, we invested in the Shore Power Plant in New Jersey and the Fairview Power Plant in Pennsylvania in the U.S. (Operation is scheduled to start in March 2020.) This was followed by investments in the Kleen Energy Power Plant and Towantic Energy Center in Connecticut and the Michigan Power in Michigan in the U.S. in 2018.
Power Generation Facilities Operated by the Daigas Group (International Facilities for Power Generation)
|Name of project||Location||Operating capacity
(Daigas Group share)
|When the project
|Tenaska Gateway IPP||Texas, USA||845,000 kW
|Osaka Gas Power America||7 plants in USA||1,446,000 kW
|Different power generation method for each project||December 2005*1|
|Marianas Energy IPP*2||Guam, USA||87,000 kW
|Diesel engine||December 2005*1|
|Energy Infrastructure Investments*3||2 plants in Queensland, Australia||59,000 kW
|Gas engine||December 2008*1|
|Hallett 4 Project||South Australia, Australia||132,000 kW
|Wind power (2,100 kW × 63 units)||June 2011|
|Shuweihat S2 power generation and water desalination project (IWPP)*4||Abu Dhabi, United Arab Emirates||1.51 million kW
|Aurora-based solar power generation project||9 plants in Ontario, Canada||101,000 kW*5
|Solar power||February 2013-March 2014|
|St. Charles Natural Gas Power Generation Project||Maryland, USA||725,000 kW
|Shore Natural Gas Power Generation Project||New Jersey, USA||725,000 kW
|Kleen Energy Natural Gas Power Generation Project||Connecticut, USA||620,000 kW
|Michigan Power Natural Gas Power Generation Project||Michigan, USA||125,000 kW
|Towantic Energy Center (natural gas-fired power plant)||Connecticut, USA||785,000 kW
|GTCC||December 2018 *1|
|Total international power generation capacity for electricity business||7,093,000 kW
- Years and months listed indicate the time when a business license was obtained.
- Providing O&M for the Marianas power plant since February 2019
- Four gas pipelines, two gas-refining facilities, two power stations, two power transmission lines
- Water desalination capacity owned by Shuweihat S2: 10 million gallons / day
- Solar panel capacity