By: Mark Konold and Cristina Adkins
This entry is an update on the Worldwatch Institute’s Caribbean Low-Carbon Energy Roadmap project.
Worldwatch’s Climate & Energy team recently received a wind resource assessment for particular zones within the Dominican Republic. This final installment in a series of deliverables from 3TIER complements the solar analyses that 3TIER provided earlier in the project for the country’s two main cities, Santo Domingo and Santiago. With these resources, Worldwatch is now in the process of preparing a presentation of first findings for key in-country stakeholders that will be presented next month in Santo Domingo.
As was noted in a previous post, Worldwatch’s approach combines thorough policy analysis with 3TIER’s resource assessments to provide governments with options for fostering a low-carbon energy mix. These resource assessments are foundational for making planning decisions around generation and transmission in the Dominican Republic.
It was decided that because of the government’s attention to the significant potential market for decentralized solar power production and distributed generation, Santiago and Santo Domingo would receive focus for solar analysis. In addition, 55 percent of the Dominican population resides in these two cities, making them the main hubs of electricity consumption in the country. Solar power then becomes very fitting for household-scale development, whether for electricity generation or water heating.
Working with our key in-country stakeholder, La Comisión Nacional de Energía, it was decided that the provinces of Montecristi, Puerto Plata, Samana, La Altagracia, Bani, and Pedernales should be examined for their respective wind power potential. The criteria for selecting the zones included the wind resource, access to the grid, and potential intrusion protected areas, resorts, and other areas important to tourism. Other factors such as the effects on migratory birds, agricultural areas, and passage of atmospheric/weather related events were excluded from the decision-making process.
In Santo Domingo, the long-term (January 1, 1997 – December 31, 2009) average global horizontal irradiance (GHI), or the amount of sunlight that strikes a flat surface, is 5.452 kWh/m2/day. Compared globally and to the rest of the Caribbean, the city’s GHI is quite high. However, when looking at the country as a whole, it is only average. Santiago outranks the capital city with a GHI of 5.60 kWh/m2/day. Again, this is high even for the Caribbean region and is considerably higher than areas of Europe and Asia that have taken good advantage of solar technology. (Germany, for example, the world leader in solar installations, has few locations with a GHI over 3.50 kWh/m2/day).
3TIER approaches the wind analysis by breaking each province down into grids, with each point in the grid representing a square measuring 4.5 by 4.5 kilometers. Each grid point , barring topographical or other constraints, could contain 40 wind turbines. For various reasons, such a turbine density is never reached in practice, however. Such an area would more realistically hold 20 turbines. The attractiveness of a given site is gauged by estimating its capacity factor, the percentage of the turbines’ rated power that they produce on average over the course of the year. To be considered viable, sites must, in most cases, have a capacity factor above 30 percent.
Montecristi, Pedernales, and Bani are the three provinces with the best wind resource. Just under one-third (30 of 91) of the grid points in Montecristi have a capacity factor over 25 percent, and five are over 30 percent. Bani benefits from more than a 20 percent capacity factor for 41 of the 43 grid points. Over two-thirds of its grid points are above 25 percent and 18 are above 30 percent. Pedernales, on the other hand, had the largest array of grid points with very attractive winds, as 55 of its 92 grid points had a capacity factor over 30 percent. In total, the six provinces had 78 sites with a capacity factor above 30 percent, 70 percent of which were located in Pedernales.
La Altragracia and Samana clearly had the poorest resources, having only one site with a capacity factor over 20 percent between them and none above 25 percent. Puerto Plata as well had limited potential. Just over one-third of the grid points in Puerto Plata had a capacity factor of over 20 percent, but only two exceeded 25 percent, and none reached 30 percent.
Overall, most regions in the Dominican Republic have superior solar and wind potential by global measures. 3TIER’s specific analysis of these resources will help our team provide a more robust Roadmap to our project clients. Our next milestone will be to present these findings to in-country stakeholders and related parties in the coming month. Their input will then be added to our working draft to ensure that we address their concerns and priorities as they explore implementing low-carbon solutions for the Dominican Republic. Stay tuned for more!