The Gaafaru wind farm project to power the Male’ region will be operational by August 2013, the government has promised, although the cost has already soared to US$370 million from a predicted US$250 million.
The agreement between the State Electricity Company Limited (STELCO) and Falcon Energy to build and run a 75mW wind farm in Gaafaru, North Malé Atoll, should produce enough clean energy for Malé, Hulhulé and a number of resorts to “switch off their existing diesel power generators” according to the President’s Office.
The wind farm will be required to produce an uninterrupted minimum of 45mW. On windy days, “excess electricity…will be used to run a water desalination plant.” On calm days, there will be a gas turbine which can produce up to 50mW of back-up power.
GE Energy is the most likely candidate to supply the wind turbines, and will also be supplying a desalination plant and the 50 mW back-up generator powered by liquefied natural gas (LNG).
The project’s local lead, Omar Manik, told Minivan News the Gaafaru wind farm is expected to completely replace the electricity currently produced and provided by STELCO, and should save the government about US$50 million a year.
Wind speed concerns
According to an American Wind Energy Association (AWEA) 2005 report, the minimum average wind speed needed to run a utility-scale wind power plants is 6 metres per second (21.6 km/h).
The AWEA report states that because “power available in the wind is proportional to the cube of its speed… doubling the wind speed increases the available power by a factor of eight.”
For example, a turbine operating at a site with an average of 20 km/h should produce 33 percent more electricity than a site operating at 19 km/h, because the cube of 20 is larger than the cube of 19.
This means that a difference of just 1 km/h in wind speed could significantly bring down productivity in the wind farm.
According to figures published in a 2003 report by the US National Renewable Energy Laboratory (NREL), North Malé Atoll has an annual average wind speed of 4.9 m/s (17.7 km/h), with the maximum average wind speed recorded of 8 m/s (28.8 km/h).
The Gaafaru wind farm is meanwhile expected to run on a minimum wind speed of 5.7 m/s.
Manik explained that wind farm engineers relied on [a minimum wind speed of] 15 m/s for a utility farm ten years ago, but due to efficiency gains “today it’s 3.5 m/s.”
Most of the data used for the Gaafaru project was collected by Manik, with help from the Department of Meteorology, at both 40 and 80 meters above ground.
Manik noted that the important thing when gathering wind speed data is “how high it is and how much wind there is. The higher you go, the better it is.”
The masts for the wind turbines at Gaafaru will be 80 metres high, with the propellers reaching a diameter of 50 metres. Manik explained “at 80 metres there will be very good wind.”
The wind farm
Manik said a preliminary feasibility study on wind speeds has been conducted and the project is moving forward as planned.
The project is being funded and run by UK-based Falcon Energy Group, but is represents a consortium of four companies; two from the UK, including Falcon Energy, one from Saudi Arabia and one from Holland. Currently, they are surveying wind power and negotiating prices for freight, turbines and gas supply.
The wind farm will use STELCO’s power grid, but will replace its powerplant in Male’.
“The powerhouse in Malé is limited, they have land problems, fuel price problems. We need renewable energy,” Manik explained.
The wind farm should produce from 60-70mW of energy, “which is still higher than what is required by the government,” Manik said. “STELCO will still be the provider. We are selling to them and they are providing.”
The wind farm is expected to run at 85 percent productivity, and any excess energy will be automatically sent to run the desalination plant.
The project’s team is currently analysing how many turbines will be needed to produce the required 45mW of electricity. Manik noted that two 25mW turbines will be more costly than one 50mW turbine.
He said they are looking at turbines that use no oil at all, because “the most important thing for us is not the energy. It’s the coral reef,” and the turbines must therefore be 100 percent environmentally friendly.
They are also studying the pH and moisture levels in the water, Manik said, to prevent corrosion in the turbines. Anti-corrosive zinc tablets will be placed in the mast and the turbines to keep them from rusting.
The turbines will be shipped from Lisbon, Portugal, but it is proving difficult and expensive to ship them to Malé.
Back-up generator and desalination plant
The back-up generator and water desalination plant will be located in Hulhumalé and will be provided by GE. The back-up generator, a gas-powered turbine, will have a production capability of 50mW and should be installed in about eight months.
Energy produced by the back-up is expected to replace STELCO’s electricity by late next year. “The back-up generator will be the first thing to be installed,” Manik said, adding that the most important thing was relieving STELCO from having to purchase more generators next year.
He said they are currently negotiating the gas contract for the back-up with one company in Sri Lanka and one in India. First, they need to know how many gas tanks will be needed and what sizes they will need to be. Building the gas tanks, Manik said, will take about a year.
Because excess wind energy “cannot be bottled or stored,” it must be used. If it is not used, Manik explained, it will lower productivity, so any extra energy will go into powering the desalination plant.
The back-up will most likely run on liquefied natural gas (LNG) since it is the “the best option to get where we want to be: carbon neutral,” Manik said, but noted that petroleum gas (regular cooking gas) has a larger heating capacity and does not pollute the air much more than LNG.
Manik said the water produced in the desalination plant would most likely be sold to Hulhumalé, although the government has previously said it would use it for bottled water.
STELCO and power grids
The clean energy produced by the wind farm will be distributed through STELCO’s existing power grids in Malé, and distributed through new submarine cables. Manik noted the 60 km of submarine cables are very expensive to buy and lay out, and will have to be replaced in about 50 years.
He said the biggest issue with the grids is ensuring the current grids in Malé can handle the amount of energy that will be produced by the wind farm.
“If there are 75mW of power coming into this grid, this grid should handle that,” Manik said. He added that they still need to figure out whether the electricity will be coming in through STELCO’s main power generator or into the four individual grids set out in Malé.
Economics and timelines
Falcon Energy group is investing most of the US$370 million needed to fund this project. Manik noted a lot of that money will be loaned by international banks to Falcon Energy.
“International banks are very keen to invest in the Maldives,” he said, “but they need eighteen months of wind surveys. They are becoming partners, they don’t want to lose their money.”
Manik says although both Falcon Energy and the banks know there is “good wind,” they will only invest once they can see wind data collected over eighteen months, which would ensure the data is varied and accurate.
He said while the remaining wind surveys and the installation of the back-up generator are being conducted, once they have six months of data “to give us full confidence, then we will start planting the foundations for the wind turbines.”
“By the time the eighteen months are up, the turbines should be completed,” he added.
Manik said that while “the government doesn’t come up with any money, when you go into a big project like this, even the receiver has to do something, some work.”
The work he is referring to is the possibility that the government might have to “rearrange” how the clean energy will be brought into the city.
“They may have to lay some cables. Maybe. Minimum investment from the government.”
He said it would help if the project could “tap into” some of the funds recently donated to the country, both in the Donor Conference and the Climate Change Trust Fund, but said that is something they are not really thinking about.
“We have to use what is available now. And we also need to show that we are capable people.”
Manik said the cost of the project has risen from the original figure of US$250 million to US$370 million “because there is no infrastructure here, and it has to be built by us.”
The MoU states that Falcon Energy must provide an uninterrupted power supply to STELCO for twenty years “starting from a given date.”
“It has to always be transparent,” Manik said, “you are working with the government, it has to be clear.”
The wind turbines should be working by June 2013 and the back-up generator should be operational by October 2011.
Correction: the wind mast to carry out further tests is being sent from Portugal, not the turbines.