Japan’s New Emissions Math

By Roger Pielke Jr., Cross-posted from Roger Pielke Jr.'s Blog

Yesterday I posted up a short bit from the IEA which asserted that a turn away from nuclear power will make reducing emissions more difficult. Here are some numbers explaining how this works in the case of Japan.

Earlier this week the Japanese Prime Minister Naoto Kan announced that Japan was no longer seeking to source 50% of its energy needs from nuclear power and terminated plans for 14 new nuclear facilities. What might this decision mean for Japan's ability to meet its current carbon dioxide emissions reduction target of 25% below 1990 levels? Here I use wind as a measuring stick, but solar or other technologies could easily be used to tell the same story.

Here is what the Japanese government said would be needed to reach its earlier 5% reduction target:

  • Construct nine new nuclear power plant plants, improve utilized capacity to 80% (from 60%).
  • Install 5 million kW of wind power plants (equivalent to approximately 34 units).
  • Install solar panels on 5.3 million homes (an increase of 2000% over current levels).
  • Increase the share of houses satisfying stringent insulation standards out of total newly built houses from 40% today to 80%.
  • Increase the share of next generation vehicle out of total sales of new vehicles from 4% (2005) to 50% (2020).

Replacing 9 nuclear plants (1 GW at 0.8 capacity) with wind would imply in round numbers about 10,000 2.5 MW wind turbines (at 0.3 capacity) (See The Climate Fix for details). Currently, Japan has about 1,700 wind turbines. These 10,000 new ones are on top of the 6,600 already in the assumptions, or an increase of about 10 times current levels of deployment.

And this is just for the 5% reduction target. You'd have to multiply by more than 5 to get to the 25% reduction target.

Japan currently gets 24% of it energy needs from nuclear power. To replace that additional 26% that was supposed to come from nuclear (to get to 50%) implies 78,000 (!) 2.5 MW wind turbines (see TCF, p. 144, Table 4.4). The Japanese Wind Energy Association optimistically foresees 11.1 GW of capacity by 2020, or less than half that would have been needed to reach the 5% reduction target. Abandoning nuclear does not make the emissions reduction targets easier, but far, far more difficult.

I have argued that Japan's 2020 emissions reduction target of a 25% reduction was always far out of reach. I don't think that the phrase "even more impossible" makes much sense, but perhaps Japan's new political context will at least make its emissions reductions commitments "even more obviously impossible." Then again, there is always the appeal of magical solutions.