335
Calculation Results and Future Tasks As a result of the calculation, total baseline emission was 23,757 kg CO 2 , project emission was 15,891 kg CO 2 , and resulting CO 2 emission reduction was 7866 kg.
Those values for which there were no data were estimated based on similar cases.
To improve accuracy in the future, it is desirable to replace the estimated values
with directly measured data.
12.4.2.2 Seawater-Source Heat Pump
In an air-source heat pump generally used for air conditioning, outside air is used as
a heat source. Thus, hot air is supplied during summer days and cold air during
winter nights, resulting in a decline in energy consumption efficiency. In contrast,
the heat source of a seawater-source heat pump is seawater, which shows small
temperature changes throughout the day and year, thus it will use cold air even during the summer days and warm air even during winter nights by heat exchange
between seawater and air, resulting in a consistently high energy consumption efficiency. Therefore, by updating the air-source heat pump with a seawater-source heat
pump, energy consumption efficiency improves and power consumption for air conditioning decreases, so CO 2 emission reduction is expected.
An outline of the update was conducted by Yokohama Hakkeijima Inc., as shown
in Table 12.5. The equipment was installed in 2013, and the values cover the CO 2
emission reductions with the operation for one year from a month after
installation.
Calculation Assumptions Formulating the amount of CO 2 reduction required two
conditions to be satisfied simultaneously: (1) the accuracy of the CO 2 reduction
calculation is high to secure the reliability of carbon credits, and (2) the calculation
is as simple as possible to reduce the burden on creditors. However, since these
conditions are in a trade-off relationship, Yokohama City tried to maintain a balance
between the two.
Calculation of Target Emission Activities Calculation of the targets of CO 2
reduction was based on the introduction of methodology EN-S-002 (ver. 1.0) of the
J-Credit Scheme (Japanese Ministry of Economy, Trade and Industry, 2013). As
shown in Table 12.6, use of electricity by the seawater-source heat pump, heat- source
water pump, and air-source heat pump was extracted for the calculation of target
activities.
12 Carbon Offset Utilizing Coastal Waters: Yokohama Blue Carbon Project
Calculation Results and Future Tasks As a result of the calculation, total baseline emission was 23,757 kg CO 2 , project emission was 15,891 kg CO 2 , and resulting CO 2 emission reduction was 7866 kg.
Those values for which there were no data were estimated based on similar cases.
To improve accuracy in the future, it is desirable to replace the estimated values
with directly measured data.
12.4.2.2 Seawater-Source Heat Pump
In an air-source heat pump generally used for air conditioning, outside air is used as
a heat source. Thus, hot air is supplied during summer days and cold air during
winter nights, resulting in a decline in energy consumption efficiency. In contrast,
the heat source of a seawater-source heat pump is seawater, which shows small
temperature changes throughout the day and year, thus it will use cold air even during the summer days and warm air even during winter nights by heat exchange
between seawater and air, resulting in a consistently high energy consumption efficiency. Therefore, by updating the air-source heat pump with a seawater-source heat
pump, energy consumption efficiency improves and power consumption for air conditioning decreases, so CO 2 emission reduction is expected.
An outline of the update was conducted by Yokohama Hakkeijima Inc., as shown
in Table 12.5. The equipment was installed in 2013, and the values cover the CO 2
emission reductions with the operation for one year from a month after
installation.
Calculation Assumptions Formulating the amount of CO 2 reduction required two
conditions to be satisfied simultaneously: (1) the accuracy of the CO 2 reduction
calculation is high to secure the reliability of carbon credits, and (2) the calculation
is as simple as possible to reduce the burden on creditors. However, since these
conditions are in a trade-off relationship, Yokohama City tried to maintain a balance
between the two.
Calculation of Target Emission Activities Calculation of the targets of CO 2
reduction was based on the introduction of methodology EN-S-002 (ver. 1.0) of the
J-Credit Scheme (Japanese Ministry of Economy, Trade and Industry, 2013). As
shown in Table 12.6, use of electricity by the seawater-source heat pump, heat- source
water pump, and air-source heat pump was extracted for the calculation of target
activities.
12 Carbon Offset Utilizing Coastal Waters: Yokohama Blue Carbon Project