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| Fig. 1: Illustration of the a hydropower plants workflow. (Source: Wikimedia Commons) |
Hydropower plants are being developed as a source of renewable energy in a few areas throughout the world. Specifically, they rely on elevated differences of water to generate a force that allows electricity production, usually in the form of dams. In the Caribbean and Latin America, the generation of renewable energy to supply electricity have been argued to pose benefits in cost, in addition to the reduction of using natural gas resources. In fact, the process of hydropower energy generation, illustrated in Fig. 1, produces only 11 liters of CO2 per kilowatt-hour. [1] However, it comes with its own concerns related to thermal generation. Unfortunately hydropower is problematic in the Caribbean and Latin America due to lack of water elevation.
As expected with the increased global demand for energy, there is an increase in demand for electricity in the the Caribbean and Central America, which one would hope could be provided by the region's surface water production. Particularly, it is a common occurrence in the Caribbean to have sporadic power shortages. A major push for electricity generated by hydropower in the Caribbean is to help to reduce these occurrences. However, the impracticability in this is illustrated by the potential of hydropower in the small island of Jamaica. Though the goal of being energy self-sufficient may be well within reach for similarly sized Caribbean nations, Jamaica's hydropower potential can be used as a model disproving that hydropower would play a main role in achieving this goal, even in the Greater Antilles with relatively higher and larger water bodies.
The international energy agency shows that the residential sector of Jamaica consumed 4099 × 1012 J in 2020, which corresponds to an average power of
| P0 | = | 4.099 × 1015 J y-1 365 d y-1 × 24 h d-1 × 3600 sec h-1 |
= | 1.30 × 108 Watts |
Keeping in mind that is merely a small fraction of Jamaica's overall energy consumption, this already large amount points to the unlikelihood that hydropower will completely offset the consumption. However, more concrete information can be pulled from calculating the energy produced by Jamaica's tallest dam using the following equation:
where Φ is the flow of water in m3/sec, ρ = 1000 kg m-3 is the density of water, g = 9.8 m sec-2 is the acceleration due to gravity, and h is the height of the water drop, usually a dam, in meters. Thus Jamaica's Heritage dam, which is 43 m high and supplies 0.54 m3/sec would have a power capacity of [2]
This amounts to a fraction P/P0 = 1.77 × 10-3 (0.177%) of Jamaica's electric power needs.
As shown by such a small power estimate for one of the highest dams in the region, dams and reservoirs that are already being used for irrigation do not prove to be the most feasible source of alleviating the islands' electricity needs, even on a sectoral basis. In a most ideal system, environmentalists assessing this potential may want to see this translate to offsetting of what is currently accounted for by crude oil consumption. However, the slower flow rates and smaller heights of most waterways in the region raises the need to recognize its energy limits.
As shown above, hydropower potential in the Caribbean and Latin America, even with efficient strategy, may not offset energy consumption in the regions with the implementation of hydro turbines. The major issue here lies in the Caribbean islands not having enough mountains or enough rainfall to sustain sufficient hydropower plants. The use of many of already irrigation-based dams for the purpose of hydro is not very viable and it may be best to focus on other resource-supported opportunities to move towards renewable energy.
© Kyle Lambert. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
[1] M. Escobar, F. L.López, and V. Clark, "Energy-Water-Climate Planning for Development Without Carbon in Latin America and the Caribbean," Stockholm Environment Institute, 2011.
[2] N. Miller, A. Harlan, and L. Waite, "Water Resources Assessment of Jamaica ," U.S. Army Corps of Engineers, February 2001.
