275kW Vergnet wind turbine at Grand Maison, Guadeloupe.
Photo: H Samuel
Prior to my visit, I knew a few things about what was happening on the French-Caribbean island of 660 square miles (I should say 1710 sq km) and 460,000 people. I had previously written about their geothermal power plant and I was generally aware that there was utility-scale wind energy being used; my impression was that there was a large-ish wind farm on the island.
I soon found out how wrong I was: Guadeloupe boasts a grand total of thirteen wind farms, with over 200 wind turbines having a total installed capacity of 25 MegaWatts. That’s only a slice of the renewable energy pie: In addition to the 25MW of wind and the 15MW of geothermal power, Guadeloupe benefits from almost 60 MW of biomass (mostly bagasse from sugar cane); 8.7 MW of hydro power and 2 MW of grid-connected photovoltaics. And, there are 30,000 solar water heaters installed on the island.
In absolute terms, that sounds pretty impressive, but in overall percentage terms, not so much. Renewable energy accounted for 14% of all electricity used on Guadeloupe in 2008, which is less than the figure for St Vincent and the Grenadines, which in 2008 had 17% of its electricity supply from hydro, or Dominica, which had 24% hydro electricity that year.
More to the point is that the local government in 2007 drew up ambitious plans to increase the share of wind and other renewables to a very impressive 50% by 2020. Called the PRERURE (long-term regional energy plan of prospecting and exploitation of renewable energies and the rational use of energy), the plan was formally adopted in May 2008 and is now being implemented. According to Mr Louis Galantine, president of the Commission Energie de Guadeloupe, the plan’s objectives are “ambitious, but realistic and doable”.
One project now approaching completion under the plan is a new school that will be completely powered by renewables. It’s an impressive green energy project (though I think some aspects of it may be overdesigned). The school is intended to house 1200 secondary-level students and their estimated one million kWh of annual electricity consumption is to be entirely supplied by a combination of grid-connected photovoltaics, biomass and wind energy.
Renewables-powered school under construction in Guadeloupe.
Photo: H Samuel
The wind energy is already being generated a few miles away at the Grand Maison wind farm developed by French company Aerowatt, comprised of 5 turbines of 275 kW each, for a total installed capacity of 1.375 MW.
The Grand Maison turbines, made by French company Vergnet, are specifically designed for the Caribbean challenge: they incorporate special lattice towers that are able to be quickly winched down to the ground and secured to a docking frame when a hurricane threatens – as was successfully done in August 2007 as hurricane Dean approached the islands, only a few months after the wind farm was commissioned. (Dean went on to wreak havoc on Dominica’s hydro output by causing a landslide that destroyed one of the island’s three hydro power-stations).
This design approach addresses what I think is perhaps the major problem with wind energy in the region, but the approach also has other benefits. Because the use of a collapsible lattice tower limits the turbine size, this suggests the use of numerous, relatively small turbines spread across the island, as opposed to fewer, larger turbines in one location, to produce a given amount of output.
I believe that this outcome helps to address the intermittency problem of wind power – that sometimes the wind is strong enough to produce energy and sometimes not. If wind power is not available at the same time that there is high demand for power, then the power has to be provided from another source – which tends to be a fossil fuel source.
Because of this, wind power is often considered a fuel replacement option, which cannot completely replace investment in baseload power capacity: the utility still has to have some capacity to cover the idle wind capacity. This balancing act is easier if the wind capacity is broken up into smaller, widely spread units, some of which may be available when others are not.
I think the French Caribbean model is showing us how we should think about wind energy in the Caribbean. Perhaps another trade mission for a closer look is in order?
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