False. SO VERY false.  Almost to the size of a standard GOPs. 

First off, ALL OF THOSE that are close to 100% (and none are), are based on a combination of hydro, geo-thermal and nuclear. 

Secondly, Puerto Rico is nowhere close to 100%. 
https://en.wikipedia.org/wiki/Puerto_Rico_Electric_Power_Authority

Third, Paraguay is 100%, but 9% is from hydro. 
Northern region of SOuth America just suffered several years of drought with a LOT MORE coming. Paraguy, Costa Rica and Venezuela have been suffering HUGE due to their near exclusive dependence on hydro.

Fourth, Costa Rica is about 99% renewable, but that is mostly geo-thermal and hydro. Luck for Costa Rica, by being diversified, they did not suffer near as much as Venezuela and Paraguay. But that was due to DIVERSITY. This way when weather becomes a catrosphe for them (i.e little rain), they can pull on geothermal, wind, and solar. Do note though that wind and solar COLLECTIVELY account for less than 5% of C.R.s electricity.