4 nuclear reactors’ worth of renewable electricity wasted in southwest Japan – About Your Online Magazine


FUKUOKA – There have been frequent cases in the Kyushu region of southwest Japan where electricity generated from renewable energy sources such as solar energy is not used. Within days, even the equivalent of four nuclear reactors of generating capacity is wasted without being transmitted. Why is this happening when the government should be aiming for carbon neutrality by 2050 and making renewable energy the main energy source?

To maintain a balance between electricity supply and demand, power companies conduct “production control,” asking generators to temporarily reduce power generation when electricity use is low. This is the case, for example, in spring and autumn, when the use of air conditioning is reduced. If the balance between supply and demand changes by continuing to generate and ship electricity, even if demand is low, at worst it could cause a large-scale blackout.

For this reason, on days when there is a probability of an electricity surplus, energy companies have a rule of asking generation companies to reduce their production in the following order: (1) thermal, (2) biomass, (3) solar and wind, (4) hydroelectric, nuclear and geothermal. This order was decided based on the cost of power generation and whether production could be easily adjusted.

The solar power generation facility is progressing in Kyushu due to the geographic advantage of the region being blessed with sunlight. Kyushu Electric Power Co.’s service area, which has a production capacity of 10 million kilowatts, was the only one in Japan to have implemented production control since October 2018.

The number of production control days in fiscal year 2018 was 26 days in the six-month period from October, and in fiscal year 2019 it jumped to 74 days. In fiscal year 2020, the number has dropped to 60 days because the No. 1 and No. 2 reactors at the Sendai nuclear power plant in Kagoshima Prefecture were shut down for about seven to eight months, but it is expected to increase to 95 days. in fiscal year 2021. This is approximately one in four days that any mill will have its production reduced.

In particular, from March 19 of this year, when the plant’s four reactors returned to full operation (with a total output of 4.14 million kilowatts), to May 11, when the rainy season began in parts of Kyushu, Renewable energy production was reduced by a total of 37 days, or about 70% of that period.

During this time of year, use of air conditioning and heating declines and electricity demand drops to the 6 to 8 million kilowatt range. With the four reactors operating at full capacity, there will be a large surplus of renewable energy during the day on sunny days. On April 18, a record 3.82 million kilowatts of renewable energy was reduced, the equivalent of four nuclear reactors.

An executive at Nagasaki Prefecture-based Chopro Co., which operates a total of 17 solar plants in Kyushu, said in a resigned tone: “Almost every day, some of our plants fail to be accepted (by energy companies). Even if we shut down operations, costs will still be incurred, so our profits will decrease. Above all, it would be like throwing away the electricity we generate, so it’s a waste.”

In short, the first “barrier” to the use of renewable energy was nuclear power plants. Kazuhiro Ikebe, president of Kyushu Electric Power Co., said: “If we can increase the operating rate of existing nuclear power plants, the cost of reducing CO2 emissions will be lower.”

If production control continues, the government’s goal of making renewable energy the main energy source will be far from being realized. As for offshore wind power generation, which should be a mainstay of renewable energy in Japan alongside solar power, the Goto Islands in Kyushu’s Nagasaki Prefecture are considered the country’s second-best location after Hokkaido, but if current production if control continues, there is a risk that this opportunity will be removed.

Production control is also expected to take place in Hokkaido and the Shikoku region, where the introduction of renewable energy is progressing, as early as fiscal year 2021, so it is no longer just an issue for Kyushu.

Another “barrier” to avoid wasting renewable energy is the lack of interconnection lines to transmit electricity to other regions when there is a surplus. If there is enough capacity on the interconnecting lines, even if there is a surplus in Kyushu, it can be transmitted to the main Japanese island of Honshu, where demand for electricity is high, thus reducing waste.

For this reason, the national government has also started to increase the number of interconnection lines. According to a proposal compiled in late April by Japan’s Organization for Transregional Coordination of Transmission Operators – a government-backed corporation – the state plans to double the transmission capacity of the Kanmon interconnection line connecting Honshu and Kyushu, and build a new one interconnection line between Kyushu and Shikoku. This will even triple the transmission capacity between Kyushu and other regions. It also plans to establish additional interconnection lines between Shikoku and Kansai, and Hokkaido and Tokyo.

Renewable energy generated in areas blessed with sunlight, wind power and large fields will be transported to urban areas where demand for electricity is high. Strengthening interconnection lines is an essential task in making renewable energy the main source of energy, but the Ministry of Economy, Trade and Industry does not expect to start operations until “the second half of the 2030s”, according to officials from the Ministry.

In addition, the principle of sharing the construction cost, which will be up to 1 trillion yen (about US$9.13 billion) just for Kyushu, “in proportion to the benefit each energy company receives” was decided, but the details have not yet been finalized. It will be a long time before renewable energies are ​​wasted.

Yukari Takamura, a professor at the Institute for Future Initiatives at the University of Tokyo and an expert on renewable energy, said: “Now that the entire country is moving towards ‘decarbonization,’ it is unreasonable to waste large amounts of renewable energy through control of production. “

In particular, said Takamura, Kyushu “clearly needs to start building (interconnection lines) as soon as possible, taking into account the increase in solar energy and the addition of more offshore wind energy in the future.”

(Original in Japanese by Yoshihiro Takahashi, Fukuoka Business News Department)

Paula Fonseca