On March 22, 2022 the Tokyo Electric Power Corporation (Tepco) warned electricity consumers in east Japan about the risk of rolling blackouts from a tight supply situation. The recent M7.3 quake near Sendai had knocked several of Tepco’s thermal power plants offline, which left the company in a difficult situation when a cold spell with snow flakes hit the region of the capital. Demand at times exceeded generation capacity and only the availability of pumped hydro storage saved the day before measures to curb demand such as turning down heating and switching off lights averted an outage.

No doubt this experience will increase pressure to restart more nuclear power stations that have been shuttered since the tsunami and nuclear meltdowns in Fukushima in March 2011. Before the nuclear disaster about 30% of Japanese generating capacity were nuclear; now only about 10% comes from restarted nuclear reactors. The current high prices of natural gas will further enhance the attraction of nuclear, at least in the eyes of anyone whose financial interests are tied to the balance sheet of the utility companies, such as their individual and institutional shareholders.

However, that is not the whole story.

While eastern Japan was in a power crunch, western Japan has ample spare capacity, as did Hokkaido. Why could this power not be used in Tokyo? You would have thought Japan would have learnt its lesson from the 3/11 disaster in 2011 and addressed it in the decade since then, but you would be wrong: Japanese electricity markets are still split between a handful of regional near-monopolies with minimal interchange capacities between them. For example, the Hokkaido grid has a generating capacity of 7.5 GW but only 0.6 GW of interchange capacity with Honshu (8% of the total). Tepco supplies up to 47 GW to customers in its area but can only exchange up to 1.2 GW with major utilities in the west of Japan. This leaves little margin when earthquakes or weather events with a regional impact hit supplies.

By contrast, China has built huge high voltage direct current (HVDC) transmission lines between the industrialized coastal cities on one side and hydroelectric power stations near the Tibetan plateau and solar and wind farms in the arid north on the other. Many of these lines are longer than the distance from Tokyo to Hokkaido, let alone Tokyo to Kansai. The Chinese government understands that if it wants to wean itself from the dependence of dirty coal or imported oil and gas then it will need to vastly increase power transfer capacity from the interior of the country where renewables are available to the densely populated urban areas near the coast lines.

Japan is actually in a similar situation. The elephant in the room that nobody wants to talk about is offshore wind. While European countries and the US are building up tens of Gigawatts of offshore wind power capacity, Japan has very little installed capacity, particularly offshore. The entire conversations seems to be about nuclear vs. solar vs. gas vs. coal, leaving out one of the most promising renewable energy sources available to Japan. So far the regulatory hurdles for erecting and connecting wind turbines in Japan have been high and that has left wind as an also ran compared to much more widely deployed solar. However, solar does not provide power at all hours. Wind would complement it.

Much of the European wind power capacity is installed offshore where wind speeds tend to be high and more consistent than onshore. This is where the largest and most economical turbine models tend to be used. By contrast, almost 99% of Japan’s wind power capacity is still onshore. A cumulative total of only 51.6 MW of offshore wind capacity was installed at the end of 2021 while total installed wind power capacity was 4.6 GW. Meanwhile the UK had 24.7 GW of wind power capacity, Spain 27.1 GW and Germany 62.2 GW. China is in a league of its own with 282 GW, more than all of Europe combined. Japan’s installed wind power base is less than that of small European countries such as Belgium (4.7 GW) that have relatively short coast lines and tiny EEZs: Japan’s EEZ of 4,479,388 km2 is over 1000 times larger than Belgium’s at 3,447 km2!

Japan is really only starting to build up offshore wind capacity, with projects off the coasts of Akita, Chiba and Nagasaki getting under way in the last two years. By 2030 its goal is for 10 GW of offshore capacity either installed or under construction which is still tiny compared to the already installed base of Germany, Spain or the UK.

Unlike fossil fuel or nuclear power stations, wind turbines are not location independent. They will be installed where wind conditions are favourable, where the sea is not too deep and connections to the coastal grid are cost-effective. To make the most of the wind conditions, the grid will need to be greatly expanded to allow large amounts of power to be transferred from regions with plenty of wind to regions with many consumers. This will be quite different from the current model where utility companies try to generate all the power they need within their own region, which is why there is only limited interchange capacity to help out if one company loses a large part of its generating capacity as happened in the recent quake or after 3/11.

Japan needs to start building high capacity long distance HVDC power lines like China has in order to enable a transition to zero carbon electricity. The fragmented power markets dominated by local utility companies are an obstacle to this transition as the interests of the regional companies seeking profits from existing investments in their area are not aligned with the interests of the consumers who want reliable green energy regardless of where it comes from.

Japan quickly needs to remove regulatory obstacles to expanding wind power and then invest to build a HVDC backbone to connect renewable power generation with consumers.