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 Central District of Minato Mirai 21 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. These plants centralize the boiler and chiller equipment, which 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 that include the Tokyo waterfront subcenter, the Marunouchi area, and Roppongi Hills.
　The Central District of Minato Mirai 21, 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 Central District of Minato Mirai 21. 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.

　District heating and cooling involves intensive heat production based on the heat source centralization, so energy and related costs can be saved due to increased operational efficiency, and this results in reduced air conditioning costs compared to stand-alone heating and cooling. The costs of district heating and cooling include recovery of the investment in boiler and chiller facilities and personnel expenses for operation and maintenance of the equipment. 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 varied factors into account.
　According to research by the 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 ¥5.03 per MJ in fiscal 2016. Since we started supplying heating and cooling in 1989, we have lowered the charges five times, representing about a 30% discount in charges over that period.

Note: Not including homes.

　For heat supply areas where it is difficult to choose heat source equipment as opposed to heat supply because the use of heat supply is regulated by agreements and real estate contracts, etc. wherein the Minister of Economy, Trade and Industry has stipulated particularly high requirements for the protection of consumer interests (“specified service areas”), it is mandatory to supply heat based on supply regulations that have been approved by the Minister of Economy, Trade and Industry with regards to rates and other supply conditions.
　The use of district heating and cooling in the Central District of Minato Mirai 21 is incorporated in the aforementioned Basic Agreement on Town Development Under Minato Mirai 21, so it is designated as a “specified service area” by the Minister of Economy, Trade and Industry.