*1 Gas engine-based CHP systems generate electricity and recover exhaust heat generated as a by-product.
*2 Upgraded CGS: Two 930 kW-class gas engines, total efficiency of 72% (38% power generation, 32% exhaust heat capture)
TG Hiranuma Building that Received the Environment Minister’s Award for a Global Warming Prevention Activity
*1 The government gives subsidies for leading housing and construction projects for CO2 emission reduction after publicly soliciting applications.
*2 The Building Energy-Efficiency Labeling System. In the system, a third-party evaluation body assesses and certifies the energy-saving capabilities of green buildings under the Act on the Improvement of Energy Consumption Performance of Buildings (Building Energy Efficiency Act).
*3 A zero-energy building (ZEB) aims to achieve zero net primary energy consumption, or the equal balance between total energy used and renewable energy generation, on an annual basis. The government is promoting these buildings, putting the initiative into its basic energy program.
Earth Building Tachikawa (TG Tachikawa Building) Acquisition Top CASBEE CertificationThe Earth Building Tachikawa (TG Tachikawa Building), was renewed in July 2015 as a middle-scale office building (five stories above ground, about 10,600 m2). Aiming for a ZEB, we have given environmental consideration, such as the use of renewable energy and highly efficient equipment and appliances, in operating the Earth Building Tachikawa. The building also excels in ensuring business continuity in case of an earthquake with its system that combines seismic isolation and vibration suppression equipment. It received the top S certification in CASBEE*4 for buildings, the first for a Tokyo Gas building. In fiscal 2016, it acquired BELS certification. (The assessment was four stars, out of five.)
*4 Comprehensive Assessment System for Built Environment Efficiency: assesses the environment performance of buildings and gives ratings on a scale of five.
Earth Port as ZEBIn 2010, we began renovating the Tokyo Gas Kohoku New Town Building, dubbed Earth Port. The primary goal is to achieve zero net primary energy consumption on an annual basis by 2030 by increasing the efficiency of equipment and optimizing energy use at a number of buildings. We were able to reduce the building’s primary energy consumption by about as much as 49% and CO2 emissions by around 54% in fiscal 2015 by incorporating renewable energy sources such as solar thermal and photovoltaic power generation and optimizing the operation of the CHP system.
Saving Energy through Better Use of Equipment and FacilitiesWe hold an energy-saving committee at each building where we lease an office, among the building’s owner and equipment administrator and the relevant section of ours. The committee helps examine energy use, optimize temperature and humidity and arrange energy conservation patrols, encouraging each of our employees to promote energy-saving activities.
Example of visualization at the Hamamatsucho head office building
Poster for an energy conservation campaign
In July 2018, the Gas Science Museum began purchasing renewable energy based on non-fossil fuel certification under the FIT*1 program to cover approximately 30% of the electricity used at the facility. As a result of this shift, the museum’s actual CO2 emissions from purchased electricity for fiscal 2018 declined by 78% from the previous fiscal year. The remaining 70% of the energy used at the facility is generated by highly efficient fuel cells using clean natural gas.
■Power Supply System for the Gas Science Museum
*1 A Green Menu offered under the ENNET program based on a CO2 emission factor of zero. Of electricity provided under the program, Tokyo Gas purchases electricity from renewable energy sources by using non-fossil fuel certification in the FIT program.