4. In cities, towns, and villages with good wind speed and solar radiation, the
certified capacity of solar power generation is higher than that of wind power
generation. For example, in Hachinohe City, Aomori Prefecture, the annual
average wind speed is 6 m/s or more, but the certified capacity for wind power
generation of 20 kW or more is zero, while the certified capacity of solar power
generation of 10 kW or more is 207 MW.
5. Among 18 municipalities where wind speed is 6 m/s or more, the total certified
capacity of solar power generation of 10 kW or more is about 419 MW, while the
total certified capacity of wind power generation of 20 kW or more is approximately half that, at 204 MW.
This analysis shows that the certified capacity of photovoltaic power generation is
large in general, even in areas where solar radiation conditions are not good and
wind power generation would be suitable. However, the capacity of Japan to adopt
renewable energy is limited because of the poor regional grid. Therefore, when solar
power is used alone in large quantities, there is insufficient room on the grid to accept
energy from other renewable sources such as wind power. It will be difficult to
introduce biomass or wind power generation in order to maintain the stability of the
entire electric power system unless the connection capacity is increased.
21.1.2 Mismatch Between Certified Renewable Energy Power
Generation and Power Demand
There is a mismatch between the amount of certified renewable energy generation
equipment and power demand in all regions of Japan. For example, in the area under
the jurisdiction of Kyushu Electric Power, power demand is small, and the certified
capacity of solar power generation facilities of 10 kW or more is the largest in the
country. In contrast, certified capacity in areas covered by Tokyo Electric Power
Company and Kansai Electric Power Company, which have high power demands, is
small.
Such a mismatch would not be a problem if electric power could be freely
exchanged between regions. However, the lack of interregional transmission lines
limits the potential for large-scale power interchange. Therefore, most electricity
generated by renewable energy facilities must be consumed locally. In areas where
power consumption is low, the ability to adjust frequencies is usually small, so
intensive introduction of renewable energy generation in these areas may increase
the risk of exceeding frequency adjustment capacity. In order to reduce the burden of
frequency adjustment, priority connection rules for power from renewable energy
must be changed.
1 In some cases, it is also necessary to suppress the output of
1 On January 22, 2015, the Ministry of Economy, Trade and Industry promulgated the Renewable
Energy Special Measures Law, Ministerial Ordinance to revise a part of the enforcement rules,
changing the conventional priority connection rules for renewable energy and giving priority to
392
W. Zhou et al.
certified capacity of solar power generation is higher than that of wind power
generation. For example, in Hachinohe City, Aomori Prefecture, the annual
average wind speed is 6 m/s or more, but the certified capacity for wind power
generation of 20 kW or more is zero, while the certified capacity of solar power
generation of 10 kW or more is 207 MW.
5. Among 18 municipalities where wind speed is 6 m/s or more, the total certified
capacity of solar power generation of 10 kW or more is about 419 MW, while the
total certified capacity of wind power generation of 20 kW or more is approximately half that, at 204 MW.
This analysis shows that the certified capacity of photovoltaic power generation is
large in general, even in areas where solar radiation conditions are not good and
wind power generation would be suitable. However, the capacity of Japan to adopt
renewable energy is limited because of the poor regional grid. Therefore, when solar
power is used alone in large quantities, there is insufficient room on the grid to accept
energy from other renewable sources such as wind power. It will be difficult to
introduce biomass or wind power generation in order to maintain the stability of the
entire electric power system unless the connection capacity is increased.
21.1.2 Mismatch Between Certified Renewable Energy Power
Generation and Power Demand
There is a mismatch between the amount of certified renewable energy generation
equipment and power demand in all regions of Japan. For example, in the area under
the jurisdiction of Kyushu Electric Power, power demand is small, and the certified
capacity of solar power generation facilities of 10 kW or more is the largest in the
country. In contrast, certified capacity in areas covered by Tokyo Electric Power
Company and Kansai Electric Power Company, which have high power demands, is
small.
Such a mismatch would not be a problem if electric power could be freely
exchanged between regions. However, the lack of interregional transmission lines
limits the potential for large-scale power interchange. Therefore, most electricity
generated by renewable energy facilities must be consumed locally. In areas where
power consumption is low, the ability to adjust frequencies is usually small, so
intensive introduction of renewable energy generation in these areas may increase
the risk of exceeding frequency adjustment capacity. In order to reduce the burden of
frequency adjustment, priority connection rules for power from renewable energy
must be changed.
1 In some cases, it is also necessary to suppress the output of
1 On January 22, 2015, the Ministry of Economy, Trade and Industry promulgated the Renewable
Energy Special Measures Law, Ministerial Ordinance to revise a part of the enforcement rules,
changing the conventional priority connection rules for renewable energy and giving priority to
392
W. Zhou et al.