World Hydroelectric Energy

L. David Roper
6 April, 2016


This is an attempt to project world geothermal-energy installations into the future.

Three good sources of information about hydroelectric energy are:

  1. (data for nations and the world)

I use the data from those sources in this calculation. I do not regard hydroelectric energy as "renewable energy" because much environmental damage is done when dams are constructed and the dams have a lifetime due to silting of the lake created and deterioration of the dam with time.

Fit to the Data

For the last decade world hydroelectric-energy growth had passed the time of exponential growth and was on the break point of the S curve. Of course, at some future time it has to level off. The hyperbolic-tangent function is a good function for fitting physical data that start off exponentially and approach an asymptote exponentially, such as is expected for renewable energy.

The fits given here involve fitting the hyperbolic-tangent function,


by varying its three parameters to the estimated solar-photovoltaic-energy consumed in Terrawatt-hours each year.

The following graph shows the best fit to the hydroelectic data:

This shows the fit to the geothermal-energy data for an asymptotic value of 5036 Terrawatt-hours per year with a break-point year at 1998 and a hyperbolic-tangent widthof 55 years.

This shows the projection of the fit into the future.


I rough estimate of the future availability of hydroelectric energy is given.

World Renewable Energy

L. David Roper Interdisplinary Studies