GGP per capita

A guessing game which makes you think about how GGP (God Given Product per capita) is a nice natural metric to measure the potential of a country, especially for those that are traditionally considered poor.

From photosynthesis 6*18 g of water and 6*44 g of CO2 are converted to 180 g of glucose, which is 720 kCal of energy. This means 1 g of water gives ~30  kJ.

If all the rainfall water is used by plants for photosynthesis, then the world average of 100 cm per year rain can be converted to 974 W/m^2. 
In comparison, the average solar power is 170 W/m^2.

A human only needs ~ 100 W worth of food and ~ 1kW for electricity to thrive,  and there seems to be sufficient rain and sun to provide these. 

Not all the water can be of course be photosynthesized,  given that 400 ppm of CO2 is ~.785 mg/m^3 multiplied by 4*10^18 m^3 of atmosphere gives ~ 3*10^12 g

Total rainfall is 510*10^12 m^2 * 1 m* 1000 kg/m^3 = 5*10^20 g per year, much higher!

Data sources:

Average precipitation in depth (mm per year) | Data (worldbank.org)

Global Photovoltaic Power Potential by Country | Data Catalog (worldbank.org)

Population density (people per sq. km of land area) | Data (worldbank.org)