Solar energy
There is a need for clean renewable energy.
In the year 2000 the global energy use was 13 TW (= 13 x 10 12 W) and a doubling is predicted by 2050.
The nuclear option would be to build ca. 10 000 1 GW power plants, or about one every day for the coming 40 years.
The incoming solar energy to earth is 120 000 TW.
Large-scale photovoltaic solar energy conversion is a possible option with 10% efficient solar cells, about 0.1 % of earth’s area needs to be covered, which is 6% of the Sahara desert.