Sustainable energy conversion in ruralareas in Cuba

Sammanfattning: This study focuses on the village of Los Tumbos. It is located in a mountainous area of Cuba, farfrom the closest electric grid. The village consists of a few public buildings and around 80households. The public buildings and ten of the households are located in a small center that liesclose to a river. The villagers today use a few solar cells in order to electrify some importantpublic buildings and there is also an old hydropower plant which does not work at present. Theaccess to wind and biomass is very low, which makes the use of techniques involving theseunsuitable for electricity production. The options that will be used to electrify the dispersedhouseholds are solar cells. Combined with battery storage these works well, constantly able todeliver the electricity demand. They can also be used separately without connection the eachother, which eliminate the need to create a local grid. For the center of the village the locationclose to the river implies that the use of hydropower is a suitable option in order to power itsbuildings. Solar water heaters can also be used in order to give access to hot water and furtherincrease the life standards of the villagers.The model calculates the electricity demand in the village and estimates the sizes of theproduction facilities needed to meet the demand on the grid. In the model the load curves bothfor the dispersed households and the center of the village will be calculated. By using these resultsthe number of batteries and solar cell modules for the dispersed households can be calculated.For the center of the village the possible output from the hydropower plant can be calculated andthe number of collectors needed in the solar water heater system could also be estimated.From the model three different load curves were examined showing the peak-demand and thedaily average energy consumption for the demand levels. For each of the different levels the sizeof the energy conversion facilities were estimated showing the number of solar cells, batteries andsolar water heater collectors needed for the different levels. Any unambiguous result about asuitable demand level and by that the number of solar cells, collectors and batteries for LosTumbos cannot be selected without a complementary study of the economics available. This issince the economics is a very important factor in the decision. The output from the hydropowerplant is not dependent on the demand levels and it is capable of delivering a maximal power of2616 W and an average daily electrical consumption of 62,8 kWh per day. This result is verydependent on water flow and the available head and since the records were bad it needs to bereevaluated using records of the water flow from a longer time period, and an onsitemeasurement of the water head.