Conclusions
An optimisation model to evaluate the insertion of new renewables into the Colombian power sector was developed. The model considers cost-based generation competition between conventional technologies (hydro, gas and coal) and alternative renewables (solar PV and wind). Two stochastic approaches were used to provide solutions to the problem of concern e ISO and RO. These two approaches were selected because they are simple to implement, require few computational resources, facilitate the consideration of uncertain parameters while preserving their natural behaviour, and their results, although conceptually different, offer an ample perspective of the problem at hand. The results suggest that Colombia is ready for renewable energy sources and that these should be carefully considered when expanding the capacity of the system within the next fifteen years. Priority should be given to solar PV over wind power, and together they should replace the current gas and coal thermal plants in Colombia. The main reasons to support this shift are economic and technical, as well as environmental. The apparent complementarities between solar radiation and wind speeds, together with the hydrological water inputs in Colombia, make alternative renewables (particularly solar PV) optimal options to strengthen the power system by making it less vulnerable to future El Nino events. ~ Although hydroelectricity is a renewable source, it is also costly and a high dependency on it has made the system vulnerable to El Nino~ and to other potential long-term climatic changes. In terms of further research, as already mentioned, we are also working on some final elements of the complementarities between hydro, solar and wind power for the Colombian case, which should help in informing decisions regarding the placement of renewable facilities in the country.
