Energy Transition in Japan: While Nuclear Fades Out, Green Energy Has a Potential More than What Current Official Plans
A co-study of institutes in Germany and Japan revealed that renewable energy in Japan can supply 40% of the electricity with grid stability kept
(Read in 華語)
Green energy has developed strongly in Japan ever since the nuclear disaster of Fukushima began. The electricity share of renewable energy grew from 10% in 2011, to 17.4% by 2018. On the other hand, only 9 of the 60 reactors in the nation are currently delivering power, while another 24 reactors have been or will soon be decommissioned. Even if the reactors did succeed in getting the operation license, they now face closure over delayed counter-terrorism measures.
The dream of exporting nuclear industry abroad has also faced serious blow. The 16 billion pound nuclear power plant Wylfa was supposed to be the model of the cooperation between UK and Japan’s nuclear industry, but Hitachi was forced to abandon this project due to ever growing budget. Wylfa was all the Japanese nuclear industry had abroad, and the divestment of it meant that Japanese overseas nuclear projects came to an end.
It is total unbelievable, then, that despite of all the negative trends of the industry and about 60% of the population opposing the technology, the Abe cabinet still planned to have at least 20% of nuclear for electricity by 2030. What is also unbelievable is that the share of renewables they planned was only 22% to 24%.
According to the projections of Bloomberg New Energy Finance, nuclear energy will most likely take an electricity share of 12% in Japan by 2030. If Japan fails to develop more renewables and transforms its power system to a more flexible one, the 10% electricity gap due to over-expectations of a nuclear renaissance will probably be filled by coal power.
On the other side of the planet, the UK is also facing the same problem after the NPP project in Wylfa can no longer be sustained. All but one reactor in UK will be decommissioned by 2030; believing nuclear is a cheap and reliable carbon-free source, the UK government used to plan dozens of new nuclear projects to fill in the supply gap. But now, only one project, Hinkley Point C, is under construction; with ever increasing budget and perpetual delay, nobody knows when this power plant can be finished.
But the UK government dealt with their disillusioned nuclear dream differently from the Japanese. Shortly after the tragedy of Wylfa, the May cabinet quickly made a “sector deal” with the offshore wind industry promising that both parties will work together to make offshore wind power supply more than 30% of the electricity demand in UK by 2030.
This is the first time ever a branch of the green energy industry made a deal like that with the government, which used to favor the nuclear industry more before. It is a great turn of the government’s position.
We believe that the Japanese government should also adopt this policy of prioritizing renewables rather than nuclear. Some critics of the energy transition have long claimed that wind and solar are too “unreliable” to scale up in island nations such as Japan. Such claims overlooked the system change experienced recently in advanced nations of the energy transition to maintain grid stability.
The national grids of Ireland and UK are not synchronized with mainland Europe, so the two nations must rely merely on domestic flexible resources to deal with problems related to power system stability. This, however, did not stop the two nations from announcing ambitious goals for allowed instantaneous system non-synchronous penetration (SNSP, with is mainly caused by wind and solar penetration) on their grid; Ireland will allow 75% of SNSP by 2020, and the UK envisions 100% by 2025.
In comparison, the power system of Japan is about the size of Germany and France combined, so allowing higher penetration rates of variable renewables without compromising grid stability will be easier than in Ireland.
Agora Energiewende, a think tank stationed in Berlin, released the results of a study it conducted with the Japanese think tank Renewable Energy Institute. Without additional measurements, the grid can handle an instantaneous SNSP rate up to 50% in East Japan and 60% in West Japan while still meet the required frequency stability. If renewables are asked to provide fast frequency response services, another 10% of SNSP rate can be handled in both regions.
Under such high allowed instantaneous SNSP rate, the curtailment of wind and solar in Japan will still be insignificant (around 4%) even with an annual renewable share of 40%. Put it another way, the 40% low carbon electricity currently planned by 2030 can very possibly be supplied totally from renewable sources, without further technology investment.
Of course, other flexible resources (demand side response, storage, synchronous condensers, etc.) will still be needed if a higher renewable share is to be achieved. Academic studies of how Japan can achieve 100% renewable in the electricity sector are also just beginning to flourish.
Something noteworthy is that no nuclear capacity was assumed in this study; all the inflexible conventional power plants in the grid were assumed to be coal power plants. If some of the coal power plants are replaced with nuclear power plants in the model, it might not alter the analysis of grid stability, but more constraints might be imposed on the penetration rate of renewables in the analysis of economic dispatch. After all, nuclear power plants are the most inflexible among the conventional sources.
Given the industrial trends observed and relevant studies released recently, we sincerely wish that the Japanese government will reconsider its energy policies for the future. In the UK we already saw how the end of the nuclear renaissance dream threatened its climate policies, and how the government was forced to change those policies accordingly. Japan need not to repeat the history, and neither does Taiwan.
