88
power generation (also known as the enhanced geothermal system) is also effective
in reducing electricity costs, and development is also progressing in the U.S. It is
not so complex system, but more investigation and research on deep underground
structure are necessary to develop the technology for practical application. In Japan,
it would be possible to complete a power generation system of 100 TWh (13 GW)
per year by 2050.
Given that the status of use of nuclear power generation is not foreseeable in
2050, there is considerable uncertainty in the role of nuclear and geothermal power
among the stable power sources by 2050. Therefore, we have changed the annual
total power generation amount to 600–1200 TWh, and we also examined how much
nuclear and geothermal power generation would be required if the amount of electricity generated was reduced. We would also like to think about minimization of
costs when a reduction of 80% of CO 2 emissions is achieved. The unit power generation costs for nuclear power and HDR geothermal power generation and CO 2
emissions are almost equal. As a result, however the proportion of power supply
from the two power sources changes, the effect on total power cost can still be seen
by using the value of the sum of the amount of power generated by these two
sources.
5.1.3 Consideration of the Best Power Supply Configuration
Table 5.2 shows the comparison of power generation costs calculated by changing
the annual power generation amount, power supply configuration, and CO 2 reduction rate. As mentioned in the previous section, since power consumption is estimated to be 650 TWh per year by 2050, the annual demand for electricity has been
set with 700 TWh as the reference value in Table 5.2, considering that this is a
highly feasible numerical value. In addition, we calculated the cost of power generation by setting various patterns from 600 TWh, which is slightly less than the
reference value, to 1200 TWh, which is higher than the reference value.
Cases 1, 2, and 4 are examples in which the annual demand for electricity has
been set between 600 and 1000 TWh, and the amount of CO 2 emissions has been
reduced by 80%. In these cases, nuclear power generation and HDR geothermal
power generation are not included, but if the demand is less than 800 TWh, the cost
would be about ¥11/kWh in all cases. If the demand falls slightly below the current
level, it is possible to reduce the electricity cost below the current level of ¥12/kWh
even without nuclear power and HDR thermal power generation.
In contrast, if the demand reaches 1000 TWh as in Case 5, the cost rises sharply
to ¥18/kWh. Even power savings of about 20% will be effective in reducing cost
and the amount of CO 2 emissions under such a scenario.
In Case 3, the demand for power is the same as in Case 2, but the target for reducing CO 2 emissions has been increased to 90%. The power cost at this point is high
at ¥16/kWh.
5 Low-Carbon Society in 2050
power generation (also known as the enhanced geothermal system) is also effective
in reducing electricity costs, and development is also progressing in the U.S. It is
not so complex system, but more investigation and research on deep underground
structure are necessary to develop the technology for practical application. In Japan,
it would be possible to complete a power generation system of 100 TWh (13 GW)
per year by 2050.
Given that the status of use of nuclear power generation is not foreseeable in
2050, there is considerable uncertainty in the role of nuclear and geothermal power
among the stable power sources by 2050. Therefore, we have changed the annual
total power generation amount to 600–1200 TWh, and we also examined how much
nuclear and geothermal power generation would be required if the amount of electricity generated was reduced. We would also like to think about minimization of
costs when a reduction of 80% of CO 2 emissions is achieved. The unit power generation costs for nuclear power and HDR geothermal power generation and CO 2
emissions are almost equal. As a result, however the proportion of power supply
from the two power sources changes, the effect on total power cost can still be seen
by using the value of the sum of the amount of power generated by these two
sources.
5.1.3 Consideration of the Best Power Supply Configuration
Table 5.2 shows the comparison of power generation costs calculated by changing
the annual power generation amount, power supply configuration, and CO 2 reduction rate. As mentioned in the previous section, since power consumption is estimated to be 650 TWh per year by 2050, the annual demand for electricity has been
set with 700 TWh as the reference value in Table 5.2, considering that this is a
highly feasible numerical value. In addition, we calculated the cost of power generation by setting various patterns from 600 TWh, which is slightly less than the
reference value, to 1200 TWh, which is higher than the reference value.
Cases 1, 2, and 4 are examples in which the annual demand for electricity has
been set between 600 and 1000 TWh, and the amount of CO 2 emissions has been
reduced by 80%. In these cases, nuclear power generation and HDR geothermal
power generation are not included, but if the demand is less than 800 TWh, the cost
would be about ¥11/kWh in all cases. If the demand falls slightly below the current
level, it is possible to reduce the electricity cost below the current level of ¥12/kWh
even without nuclear power and HDR thermal power generation.
In contrast, if the demand reaches 1000 TWh as in Case 5, the cost rises sharply
to ¥18/kWh. Even power savings of about 20% will be effective in reducing cost
and the amount of CO 2 emissions under such a scenario.
In Case 3, the demand for power is the same as in Case 2, but the target for reducing CO 2 emissions has been increased to 90%. The power cost at this point is high
at ¥16/kWh.
5 Low-Carbon Society in 2050