Frequently asked questions

　Generally, chillers conserve more energy when they operate at high capacity (as close as possible to their full rating), because this delivers better fuel efficiency. At night and during the off season when demand is low, boiler and chiller equipment installed in individual buildings operates at low capacity, and its efficiency drops. But with district heating and cooling where heat is supplied to many customers collectively, it is possible to adjust the number of machines operating according to the demand in the district as a whole, enabling the equipment to operate efficiently at all times.
　Additionally, concentration of related facilities like pumps, cooling towers, and chimneys, as well as centralized operation by highly skilled engineers, and a range of other factors results in overall conservation of energy.

　The Minato Mirai 21 District aims for outstanding urban planning in terms of the environment, safety, disaster prevention, scenery and so on. District heating and cooling at Minato Mirai 21 is supplied by two plants which centralize the boiler and chiller equipment that requires careful handling and the cooling towers which may face regulations under the building design code, thus making a significant contribution to the District’s urban planning concept. In recent years, district heating and cooling has come to be viewed as indispensable infrastructure for urban development, in projects including the Tokyo waterfront subcenter, Marunouchi, and Roppongi Hills.
　The Minato Mirai 21 District, with its densely packed high-rise buildings and strong thermal demand, represents an ideal area for district heating and cooling to realize its full capabilities.
　Use of district heating and cooling is incorporated in the Basic Agreement on Town Development Under Minato Mirai 21, the voluntary urban planning rule of the Minato Mirai 21 District. The City of Yokohama has also established a policy promoting district heating and cooling and is actively pursuing widespread introduction of these systems.

　Supply has never gone off line or been suspended due to maintenance work on our boiler and chiller equipment. Our plant operates on 24/365 basis, sending out heat continuously.
　Ensuring a stable supply is the most important aspect of our business, and we do all we can to ensure that the machinery and equipment is well maintained. At the same time, we have backup systems in place with spare equipment in case of equipment failure. All of our customers can be supplied from either the Central Plant or No.2 Plant, and we have built a highly reliable, interconnected system. In addition, the majority of the regional conduits linking our customers and the plants are accommodated in public utility conduits that have been strengthened against earthquakes.

　Like electricity and gas, district heating and cooling businesses are public utilities. Charges and other supply conditions are subject to application and approval by the national government. The unit price of the charges is calculated strictly based on the cumulative costs (cost price) of producing and supplying heat. Furthermore, a fair unit price for charges with no inequality between customers is a requirement for business approval.

　As we explained above, the charges for district heating and cooling are calculated based on business costs. These costs include recovery of the investment in boiler and chiller facilities and personnel expenses for operation and maintenance of the equipment. With district heating and cooling, customers are spared the initial investment in boiler and chiller facilities and replacement costs. Also, the space saved can increase the rentable area, thereby increasing rent income. So there are several cost benefits that are not restricted to the cost of energy. When comparing the cost of heating and cooling each building, it is necessary to take these various factors into account.
　According to research by Japan Heat Supply Business Association, when the costs including the life cycle cost of boiler and chiller facilities over 30 years are compared, district heating and cooling works out to be approximately 4 to 10% cheaper than heating and cooling individual buildings.

　The price per unit of heat in this district for commercial facilities (total sales amount/total quantity of heat sold — or flat rate) is around ¥5.6 per MJ. Since we started supplying heating and cooling in 1989, we have lowered the charges four times. Calculated according to the flat rate, with the four price reductions, the charges have been discounted by about over 20%.
Currently, the flat rates of district heating and cooling areas in the Tokyo metropolitan region are distributed between ¥4 and ¥10 per MJ. Therefore, the rate charged by Minato Mirai 21 is at the lower end.

Notes:
1. The flat rate for each revision year is calculated based on the contract capacity and the quantity of
　heat sold in fiscal year ended March 31, 2011, and applied to the unit price for each revision year.
2. Not including homes.