Monday Message Board
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Global peak emissions?
In the end, the troubled few years either side of today will be remembered for one thing: the peak in global GHG emissions. Are we there yet?
The critical country is China, the crucial sector is electricity supply. Electricity demand in China is rising at a historically high rate of +7%, in spite of a slowdown in industrial demand. This translates to a y.o.y increase of +105 Gw continuous-equivalent. (This is a purely accounting concept, nothing to do with the “baseload” fixation).
For emissions from coal generation to fall, all the new demand has to be met by zero-emission sources. I tried to work out whether this is happening, The new capacity in 2024 (extrapolating for December) looks fuzzily like this:
• wind +79 Gw nameplate @ say 0.4 cf = 32 Gw cont-eq
• solar +230 Gw nameplate @ say 0.2 cf = 46 Gw cont-eq
• hydro +8 Gw nameplate @ say 0.8 cf = 6.4 Gw cont-eq,
• nuclear +1.2 Gw nameplate @ say 0.8 cf = 1 Gw cont-eq (so what)
Total 85.6 Gw cont-eq, a shortfall of 20 Gw cont-eq. Sigh.
But this is wrong. Thermal generation is the residual, and the National Statistics Bureau of China has a direct series for its output. They say the “accumulated growth rate” to November 2024, which I assume means the one-year CAGR, was +1.9%, or +12.5 Gw cont-eq. Meeting that would require a 15% increase in the rate of installation of new renewables, pretty much in line with historical trends. The monthly y.o.y increase in thermal generation was down to +1.4% in November. It all points to an emissions peak in the first half of 2025.
There isn’t a dilemma over the incompatible numbers. Who are you going to believe, a national statistics agency or some random blogger? Where did I go wrong? Massive fraud is a possibility, but in China perpetrators risk being shot ”pour encourager les autres”, and the required scale calls for too many conspirators for secrecy. I prefer an underestimate of capacity factors. China has been shifting wind investment to offshore, where taller turbines and stronger winds raise capacity factors to 50% or higher. Similarly solar investment has been moving geographically to the arid interior, and from constrained distributed installations to giant utility farms. In the past, Chinese solar capacity factors have been lower than American, now typically 30% for utility farms that can use single-axis trackers, which are impractical for rooftops. It is not credible that a formidable solar industry ten times the size of the USA’s should fail to match its best practice. Raising mean capacity factors to 45% for new wind and 25% for new solar more than covers the disparity in the data.
One last twist. It is no longer quite true that *net* GHG emissions from generation are
just a residual from zero-carbon generation. One of the drivers of increased demand for electricity is the rapid electrification of transport, advancing well ahead of previous estimates. Over half the new car market in China is now met by PHEVs, which have reached sticker price parity with ICEVs as well as superior driveability, a good choice of models, social acceptance and policy support. The shift is certain to continue, and likely to speed up as it did in Norway. Even if all the new electric demand for electric vehicles were met by coal power stations instead of the current 60%, their much higher well-to-wheel efficiency – roughly 40% versus 15% - would lead to a large net drop in CO2 emissions and air pollution. This factor will bring forward the net emissions peak a little.
Sources:
Electricity demand https://www.reuters.com/business/energy/china-power-demand-growing-faster-than-expected-2024-industry-association-says-2024-10-29/
Wind https://www.evwind.es/2024/12/21/chinas-wind-power-installed-capacity-in-the-country-reached-490-gw/103410
Solar https://taiyangnews.info/markets/china-solar-pv-installations-november-2024
Hydro, nuclear https://climateenergyfinance.org/wp-content/uploads/2024/11/MONTHLY-CHINA-ENERGY-UPDATE-_-Hydropower-Generation-Recovered-Driving-Down-Thermal-Power-Demand.pdf
Thermal https://data.stats.gov.cn/english/easyquery.htm , select Energy>Output of energy products>Thermal power