Power, fear, and carbon in Japan: the Iron Rule of Power Generation II

On March 11 2011, a 14-meter-high tsunami, triggered by an earthquake of unimaginable power, smashed the northeast coast of Japan. The tsunami killed about 20,000 people pretty much immediately. Watch any video of this catastrophe and you will see why. The wave also knocked out the backup power to a nuclear plant. As a result, three of that plant’s reactors lost cooling water and melted down. The panic over the meltdowns was understandable given the fear in the worldwide pop culture over anything associated with nuclear. That fear is grotesquely out of proportion to the actual danger that the meltdowns posed: after 4,585 days, not a single person has died or even gone to the hospital because of any harm caused by nuclear radiation.

But the Japanese public were spooked anyway. For that reason, the government shut down almost all the nuclear plants. And for that reason, Japan started burning more fossil fuels to make electricity. And that led to skyrocketing greenhouse gas (GHG) emissions in the country that hosted the 1997 Kyoto Protocol, the aim of which was to reduce GHG emissions. As you can see in the chart above, emissions of carbon dioxide (CO₂), the principal GHG, from Japanese power generation by combustible fuels, skyrocketed: from just over 531 million metric tons in 2010 to nearly 650 million in 2012.

The above chart illustrates starkly the Iron Rule of Power Generation. When you remove a type of energy that provides large-scale, steady, 24/7 power generation from a modern power grid, you must replace it with another form of generation that has those same attributes. Which is to say, if you remove nuclear then you must replace it with some form of combustible fuel, usually coal, oil, or gas.

Japan is no different than any other country in this respect. The generators in its combustible fuel-fired generating fleet run on coal (31.5 percent), oil (18.5 percent), natural gas (46 percent), with a tiny amount of biofuels and waste (4 percent).

And, because of the nuclear meltdown, which to repeat has yet to produce a single casualty after 4,585 days, combustible fuel generation now makes up 89.5 percent of Japan’s power.

These numbers come from the OECD Electricity Information 2013 publication, p. IV.439.

[stextbox id=”info” caption=”How did I get the CO₂ data?”]All CO₂ estimates in this article are based on estimates of CO₂ output by different types of combustible fuel generation.

Generation fuel type output in Japan is given in the OECD publication Electricity Information 2013, p. IV.439.

Japan burns four types of combustible fuel to make electricity. These are: natural gas, coal, oil, and biofuels/waste.

I assigned a top-level emission factor to each of these types. This method is crude and does not account for power conversion technology or operating conditions of each generator. But each factor is in a generally accepted ballpark. I am confident that the emission estimates are generally accurate.

Here are the CO₂ emission factors I assigned to the four types of combustible fuels that Japan uses to make electricity:

1. Natural gas = 550 grams per kWh
2. Coal = 900 grams per kWh
3. Oil = 700 grams
4. Biofuels and waste = 900 grams

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That proportion will not drop until Japan faces its fears over nuclear, admits they are wildly out of proportion to the actual danger it poses, and returns its nuclear fleet to service.

Here is a table with the OECD numbers (again, from Electricity Information 2013, p. IV.439) that the chart above is based on.

Japan power generation in TWh, and carbon emissions

	1973	1980	1990	2000	2005	2010	2011	2012e
Nuclear	9.7	82.6	202.3	322	304.8	288.2	101.8	11.2
Hydro	71.7	92.1	95.8	96.8	86.4	90.7	91.7	85.7
Combustible fuels	388.6	400.7	542.2	635.9	702.2	727.8	845.4	925.5
CO2, megatons	277.905	279.305	379.915	456.935	520.88	531.14	599.3	649.665

And here is a table that shows the CO₂ emissions associated with each type of combustible fuel generation in Japan. For the specific CO₂ emission factors applied to each fuel, see the Info box “How did I get the CO₂ data?” above. Compare Japan’s CIPK of grid electricity with that of Ontario in Table 1 in the upper right sidebar.

Japan power generation CO2 emissions by fuel, million tons

	1973	1980	1990	2000	2005	2010	2011	2012e
Coal	33.57	49.41	105.03	209.07	273.15	268.11	252.99	262.35
Oil	238.56	185.29	173.53	95.97	96.39	65.59	107.31	119.77
Natural gas	5.78	44.61	91.91	138.22	131.45	165.22	205.70	234.25
Biofuels & waste	0.00	0.00	9.45	13.68	19.89	32.22	33.30	33.30
TOTAL	277.91	279.31	379.92	456.94	520.88	531.14	599.30	649.67
CIPK, grams	590.91	484.65	451.21	431.68	473.61	475.46	570.06	628.49

[stextbox id=”info” caption=”What is the CIPK, and how is it calculated?”]CIPK stands for CO₂ Intensity Per Kilowatt-hour. It is a measure of the carbon content of a kilowatt hour of grid electricity.

The CIPK of a given grid is simply the amount of CO₂ emitted by the generating plants that feed the grid with electricity, divided by the total amount of electricity fed, over a given hour. Of course, you have to know both of these figures.

Here is how to calculate Ontario’s grid CIPK. You need to refer to Table 1, in the upper left-hand sidebar on this page. Table 1 gives the current Ontario grid generation mix (it draws from data published at www.ieso.ca), and the CO₂ emissions associated with the emitting fuel types.

1. Go to the Total row in Table 1.
2. Take the figure from the CO₂, tons column.
3. While still in the Total row, now take the figure in the MW column.
4. Divide the CO₂, tons figure by the MW figure.
5. Multiply that result by 1,000. This converts tons-per-megawatt-hour into grams per kilowatt-hour.

Try it!

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Compare Japan’s CIPK of grid electricity with that of Ontario in Table 1 in the upper right sidebar. If you want to know why there is such a difference, look at the amount of nuclear in Ontario’s electricity system versus that in Japan’s.