At Roppongi Hills, we have adopted a large-scale district energy system (Cogeneration + DHC). A huge natural gas-fueled co-generation plant recovers the waste heat from a central electrical power generation system and uses it to meet the heating and cooling needs of the community.

By generating power with gas and putting waste heat to work, the highly efficient system provides approximately 20% primary energy savings, which in turn reduces CO² and NOx emissions.

Though one of the earliest major development undertaken by Mori Building, the ARK Hills project featured the introduction of a district heating and cooling (DHC) system. A sub-plant is located in the Akasaka Intercity project, which was developed in the neighboring district, promoting the establishment of an Area Energy Network and further energy conservation.

This system averages the electrical power load over the day by the nighttime storage of the energy used for daytime HVAC operation. This redistribu- tion of the power load reduces the burden on the environment by shifting electrical power consumption to nighttime hours when the usage of fossil fuel for power generation is lower and contributes to reduced load on the power generation plant.

With its BEMS (Building Environment and Energy Management System), Mori Building has a comprehensive grasp of building energy utilization and the state of the interior climate and the knowledge necessary to optimize energy conserva- tion. The centralized monitoring system allows managers to confirm the state of energy utilization in real time. By accumu- lating and analyzing data, we can identify and eliminate excessive energy usage and waste. Under national government policy to promote the adoption of BEMS, the New Energy Development Organization (an incorporated administrative agency) known as NEDO has system of subsidies to encourage installation of energy efficient systems. Currently three Mori Building properties are beneficiaries of this subsidy program: Roppongi Hills Mori Tower, Holland Hills Mori Tower and Toranomon 37 Mori Building.

As a result of BEMS optimized management of cutting-edge energy-saving systems, Roppongi Hills Mori Tower and Holland Hills Mori Tower recorded actual annual energy consumption in 2007 signifi- cantly less than initial projections: -23% and -16.7%, respectively. Exploiting the strength of Mori Building’s integrated approach to development projects from the planning stage to operational management, BEMS Operation Promotion Councils have been organized in buildings equipped with BEMS. Working as one, our Planning Division, Management Division and various companies that support building management and maintenance endeavor to conserve energy and reduce CO² emissions.