Over at Forbes’ blog, Sara Mansur has dug into the numbers to see what it would take if nuclear were phased out in Japan:
If nuclear power were to be completely taken out of Japan’s power supply, the country’s carbon emissions would rise by at least 414 million tons over current emissions [assuming nuclear is replaced by coal and gas]. Carbon emissions would increase by at least 10% and as much as 17% across the entire economy, while power-sector emissions would soar by 29% to 49%, depending on the mix of replacement power.
What about renewables instead?
the 203 gigawatts (GW) of installed solar capacity required to replace Japan’s current nuclear fleet would cover roughly 1.3 million acres, according to a land area calculator created by the National Renewable Energy Laboratory (NREL) in the United States. That’s the equivalent of roughly 52% of Japan’s total land area.
Using an estimate of $5 per watt of installed solar PV capacity, installing this 203 GW of solar capacity would cost the country at least $1.01 trillion.
Alternatively, replacing the generation lost from a complete phase-out of nuclear power entirely with wind energy would require wind generation to increase from its current levels, 3.257 billion kWh (0.3% of total electricity), to 267 billion kWh (27% of total electricity).
This would require 152 GW of installed wind capacity, at a total installation cost of $375 billion (using an estimate of $2,466/KWe). According to NREL’s wind farm area calculator, the installation of these wind turbines would require 38,000 acres taken out of production on a wind farm, and a total of 1.3 billion acres for the entire wind farm. This represents over 50 percent of Japan’s total land area.
And that’s to replace the existing Japanese nuclear fleet. By 2030, Japan had set a goal to double it. Check out the rest of the Forbes analysis to see what it would take if other technologies met that 2030 goal instead. Hint – there’s a reason why Japan is big on nuclear.
Update, 5/2: Looks like there was a serious calculation error on the amount of land needed for wind and solar. The land space needed for solar or wind to replace Japan's nuclear fleet would take up a few percent of the country's land space, not 50% or more.