Vol.3 No.3 2010

Research paper : An optimum design method utilizing a strategic system design concept (J. Fukuda et al.)−194−Synthesiology - English edition Vol.3 No.3 (2010) is 224 thousand yen (at an amortization period of 5 years) or less. Comparing this to the general cost needed for capping, the figures are unrealistic. If capping could be done at 200 thousand yen per rack, the amount of cost reduction for the datacenter as a whole will be merely 4,217 thousand per year. It is quite impossible to achieve the condition (2) where the profit can be increased more than before tax imposition.Next, we assume a composite datacenter with the same 1,000 racks and 6 kW/rack located in Utsunomiya, and the greenhouse of 88,100 m2 size that uses the waste heat.The annual power consumption of the datacenter is 57,417 MWh, and the annual power cost ECx = 689,006 thousand yen and annual environment tax TCx = 14,354 thousand yen must be paid by the datacenter company. On the other hand, by reusing waste heat, the annual fuel consumption 1,709 kL and the annual fuel cost ECy = 241,390 thousand yen for the greenhouse heating become 0, and the annual CO2 emissions of 4,256 t and environment tax TCy = 1,402 thousand yen can be reduced. The upper limit of the annual facility investment ICx + ICy appropriate for this reduction effect is less than 191,135 thousand yen (1,124 thousand yen per rack). There is about five times cost difference compared to a single datacenter. Assuming the annual facility investment at 88,100 thousand yen (1,032 thousand yen per rack), compared to before environment tax imposition, the datacenter company will experience a profit increase of 78,646 thousand yen a year, and the greenhouse farmer will see 8,634 thousand yen more profit. With the composite datacenter, it is possible to design a system with high CO2 reduction in terms of the environment, and the company and the farmer can both enjoy high earnings.5 SummaryStrategic system design is a comprehensive design of the physical space and the psychological (value) space of the different stakeholders.As a result of investigating the design of a datacenter for the purpose of CO2 reduction, the following points became apparent.(1) In the design optimization of a single datacenter using the conventional design approach, the effect of physical CO2 emission reduction is limited, the maximum amount that can be invested for environmental improvement in terms of value is small, and facility investment is difficult. Also, it is almost impossible to maintain the same profit as before the imposition of environmental taxes.(2) In the case of the composite system where the waste heat of a datacenter is used for greenhouse farming by employing the concept of total physical system design, the overall CO2 emission reduction is 17.9 %, and there is potential for achieving greater environmental improvement.(3) As a value system based on total value system design, by introducing the contract system where the greenhouse farmer pays an adjustment cost for the use of waste heat to the datacenter company, it is possible to maintain sufficient facility investment even after the imposition of the environment tax. This shows the potential of increasing the value by expanding the profit more compared to before the imposition of environmental taxes.(4) The possibility is shown for designing an efficient system in terms of physical performance and cost-effectiveness through strategic system design for multiple stakeholders, in comparison to the conventional strategic system design that targets single stakeholders.The basic thinking of the strategic system design of attaining overall optimization by satisfying all stakeholders involved, while maintaining the overall balance of the physical system and values, can be applied to regional cooling and heating reusing the waste heat from plants and power plants, and is not limited to the relationship of datacenters and farming. It can be applied to the realization of new composite systems Table 4 Environment measure investment and improvement of earningsiDCcappingiDC+greenhousefarmingCalculation for the model caseTokyoUtsunomiyaDatacenter locationEnergy cost of datacenterEnvironment tax of datacenterEnergy cost of greenhouse farming(before use of waste heat)Environment tax of greenhouse farming (before use of waste heat)Energy cost reduction by facility investmentEnvironment tax reduction by facility investmentReduction of CO2 emissionEffect of reduction of CO2 emissionUpper limit of allowable facility investmentPer rackUpper limit of facility investment for increasing profitPer rackAmount of facility investment by datacenterAmount of facility investment by greenhouse farmerCost reduction for datacenter after imposition of environment taxCost reduction for greenhouse farming after imposition of environment taxIncrease/decrease of profit compared to before tax imposition (datacenter)Increase/decrease of profit compared to before tax imposition (greenhouse farmer)Amount of adjustment between datacenter and greenhouse farmer689,00914,354189,7341,402189,7341,4024,256-17.9 %191,1351,124175,3791,03280,0008,10093,00010,03678,6468,634173,000656,37013,674--37,4377801,058-5.4 %38,21722423,76314034,000-4,217--10,237--1,000 yen/year1,000 yen/year1,000 yen/year1,000 yen/year1,000 yen/year1,000 yen/yeart-CO2%1,000 yen/year1,000 yen/rack1,000 yen/year1,000 yen/rack1,000 yen/year1,000 yen/year1,000 yen/year1,000 yen/year1,000 yen/year1,000 yen/year1,000 yen


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