Worldwatch researchers recently returned from Haiti as a part of the Energy Roadmaps for the Caribbean Project. One exciting idea that grew out of our meetings with government, utility, and private sector officials is the potential for wind and pumped-storage hydro systems on the island of Hispaniola.
A wind and pumped-storage hydro system is an old technology with a new twist, and it is a technology that is being explored on several small islands around the world.
A model of the wind and pumped-storage hydro system on El Hierro (Source: ThomasNet News and Gorona del Viento El Hierro)
For the past half century, countries including the United States have used excess electricity from fossil fuel and nuclear power plants during periods of low power demand to pump water uphill to be stored in reservoirs as potential energy. Then, when demand peaks the reservoirs are opened, allowing water to pass through hydroelectric facilities to generate the needed electricity to meet power demand.
Today, El Hierro, a Spanish island off the coast of northwestern Africa, is developing a wind and pumped-storage hydro system to help it become the first independently 100 percent renewable-powered island in the world. The system will work by connecting five wind turbines with a total rated capacity of 11.5 megawatts (MW) to a pumped-storage hydro plant with a rated capacity of 11.3 MW. When wind generation exceeds power demand on the island, the excess electricity will be used to pump water from a low reservoir to a high reservoir situated in a 556,000 cubic meter (m3) volcanic crater. Then, when wind generation falls short of meeting the island’s power demand, water will be released from the high reservoir to a hydroelectric facility, helping to generate electricity and meet the island’s power demand. The water used in this system comes from three desalination plants connected to the wind turbines. The pumped-storage hydro system is also a closed-loop system, meaning that the same water is recycled through the system over time.
This sounds like a great fit for El Hierro, but could a wind and pumped-storage hydro system be applicable to Haiti?
One reason why this technology is so exciting for Haiti is because of the similarities between Haiti and El Hierro. Historically, each island’s (or a third of an island in Haiti’s case) lack of traditional energy resources has led it to become dependent on imported diesel fuel for electricity generation. This has made both islands vulnerable to fluctuating oil prices and supply. One goal of El Hierro’s project was to free itself from such a heavy dependency on outside sources for fuel. El Hierro – with a population of only 11,000 – estimates that implementing this system will allow it to avoid importing 40,000 barrels of oil per year and emitting 18,700 tonnes of carbon dioxide (CO2) per year. If Haiti – a country with more than 10 million people – could implement this system on a larger scale, it could go a long way in helping it to lower its dependency on imported fossil fuels and to reduce its greenhouse gas emissions.
Another benefit of this system is the services provided by the desalination plants. For El Hierro, desalinated water is used for the pumped-storage hydro system as well as for irrigation and residential use. In a country like Haiti, where half of its citizens lack access to clean water, such a system could increase access to fresh water in addition to energy. Additionally, as more than half of the country’s land is dedicated to agriculture, these desalination plants could provide a much needed consistent supply of irrigation water. Irregular rainfall and high levels of soil erosion have impeded large-scale irrigation projects as there is a lack of reliable and un-polluted water for irrigation.
The geology of Haiti is also well-suited for pumped-storage hydro systems. Haiti comprises the very mountainous western third of the island of Hispaniola. Therefore, it consists of several locations of steep elevation change, ideal for high head and effective pumped-storage hydro systems.
Wind and pumped-storage hydro systems also address some of Haiti’s greatest energy issues. In general, due to low capacity factors and a weak grid infrastructure, Haiti’s energy demand often eclipses its energy supply. Moreover, during Haiti’s dry season, it is often less capable of meeting its energy demand due to lower hydropower production. In Port-au-Prince – Haiti’s capital and largest city – available generating capacity falls from 90 MW in the wet season to 45 MW in the dry season due to a lack of available rain water for hydro production. A wind and pumped-storage hydro system could offset hydro capacity losses during the dry season and help to mitigate Haiti’s difficulties with meeting energy supply.
Despite the potential for wind and pumped-storage hydro systems in Haiti, there are barriers the nation will need to overcome. The logistics of such systems in Haiti will be more difficult than they have been in El Hierro. Besides having to power a population more than 900 times the size of El Hierro’s, Haiti will also need to invest considerable time into seeking ideal system locations, as finding extinct volcano craters conveniently located next to good wind resources is not as simple as one may think.
Nevertheless, wind and pumped-storage hydro systems present an exciting opportunity for Haiti. If Haiti can find suitable locations and generate the necessary funding for these projects, it will mark a significant step toward securing a more consistent energy supply while lowering its greenhouse gas emissions.