【エネルギー】“世界の全電力”を太陽光発電でまかなうには”全世界の屋根面積”の50％以上が必要と判明　日本でのコスパは世界でも…

▼追加ソース

元の論文より引用

Solar panels on half the world's roofs could meet its entire electricity demand – new research

India and China are the cheapest places to install rooftop solar, while the US, Japan and the UK are the most expensive.

theconversation.com

↑より引用
North America, UK, and Japan have shown the highest cost to realize the potential. This can be attributed to the high CAPEX costs in the countries, which are expected to reduce in the future due to technological innovations and reduction in import tariffs. In North America, Canada and the northeastern states of the U.S.A around the Great Lakes have the highest LCOE costs. The cost to achieve the potential in these countries ranges from 200 to 280 $ MWh−1. U.K (251 $ MWh−1) has the highest country-specific costs to achieve its potential.

CAPEX＝投資コスト・設備投資
LCOE＝均等化発電原価（発電量あたりのコスト）
ですね。

残念ながら日本では屋根置き型太陽光発電の導入コストは世界的にも高くなるようです?

↑より引用
Our assessment also shows that a minimum of 50% of the total global rooftop area is required to meet the yearly global aggregated electricity demand.

この論文では全世界で見ると屋根面積の50％以上が必要と結論付けています。世界は広いですから屋根だけでまかなうのは難しそうに思えます。

詳細は論文をご覧ください。