Total carbon dioxide emissions for fiscal year 2021 are 1,064 million tonnes.
Of the 178 million tons of carbon dioxide emitted by fossil fuel vehicles in the transportation sector, half (890,000 tons) would be reduced by switching to all-electric vehicles, as electric vehicles are twice as efficient as fossil fuel vehicles.
In addition, the energy conversion sector will see a decrease of 83.7 million tons due to the elimination of thermal power generation and oil refining.
Subtracting this total reduction of 172.7 million tons from the total emissions of 1,064.3 million tons, the remaining 891.6 million tons is equivalent to 1,937.9 billion kWh of electricity.
There is a 20% loss in the hydrogen power storage system and a 5% loss in transmission and distribution.
Adding in 25% of this loss, the additional electricity needed to achieve carbon neutrality is 2,422.4 billion kWh.
The annual power output of solar panels is generally said to be 95 kWh per square meter.
To generate the additional 2,422.4 billion kWh of electricity needed to achieve carbon neutrality through solar power would require an area of 25,499 km².
Japan's land area is 364,500 km², so approximately 7% of that area would be required.
Japan's urban area is 108,678 km², accounting for 30% of the country's land area. If we add up all the rooftops of buildings in urban areas, such as detached houses, public facilities, factories, supermarkets, convenience stores, airports, ports, and railways, as well as vacant lots, there is an area that can generate the additional electricity needed to achieve carbon neutrality. Furthermore, self-consumption by installed facilities can reduce transmission and distribution losses.
In addition, there are plans to expand renewable energy wind power generation by approximately 230 billion kWh, including both land-based and offshore wind power generation.
With government subsidies, there are plans to double or triple geothermal power output from the current level (520,000 kW) by 2030, which will add 9 billion kWh.
Hydroelectric power generation can increase electricity production by building small-scale hydroelectric power plants across the country that can be installed on small rivers, such as the Matsukuma Small Hydroelectric Power Plant, which has a capacity of 30kW (annual power generation of 210,000 kWh) and was built in Yoshinogari Town, located in the eastern part of Saga Prefecture.
These renewable energy sources have the potential to generate the additional 2,422.4 billion kWh needed to achieve carbon neutrality.
Although carbon dioxide emissions will be generated, sewage sludge power generation can increase electricity generation by 5.2 billion kWh, and general waste combustion heat generation can increase electricity generation by 25.2 billion kWh.
Total carbon dioxide emissions, including those emitted by some industries, can be kept below the amount absorbed and removed by forests.
In addition, by replacing electric boilers with the heat generation unit boiler factories, public facilities, and supermarkets can reduce electricity consumption.
As described above, it is entirely possible to achieve carbon neutrality through the use of renewable energy generation by implementing carbon dioxide reduction measures in the electricity, gas, and transportation sectors.
"Quote":URL of copyrighted work
"Greenhouse gas emissions and removals for fiscal year 2021 (Reiwa 3) (final figures1)"
https://www.env.go.jp/content/000128750.pdf
" Matsukuma Small Hydroelectric Power Plant, the smallest in Japan "
https://q0.io/research/matsuguma_01/