Wind energy in Malta: offshore wind farm

Scientists have requested a two-year extension to the L-A©¤rax Point wind mast permit to confirm results on the viability of an offshore wind farm at Mellie©¤a’s Sikka l-Bajda, which will provide electricity for some 40,000 households. Another two years of collecting data would reduce the margin of error when extrapolating the results to cover the 20-year wind farm lifetime.

Tonio Sant, director of the University’s Institute for Sustainable Energy, which is overseeing the collection, correlation and analysis of the data collected by the Malta Resources Authority, said data compilation in conjunction with the required studies would reaffirm what had already been established – that the 11-square-kilometre Sikka l-Bajda is a good location for an offshore wind farm.

Wind power studies at L-A©¤rax Point began in November 2009 after an 80-metre wind mast was installed. The data being collected from the mast is being correlated to the wind data that has been collected since 1997 from the institute’s wind station at Wied Rini, near Ba©¤rija.

“Statistical correlation, like any experimental technique, has a margin of error, especially when you are extrapolating the data to cover a 20-year period. A longer measurement period would help decrease that margin of error,” Dr Sant told The Sunday Times.

Around 19 to 24 wind turbines, each with a diameter of between 100 and 126 metres, are expected to be installed at Sikka l-Bajda, a reef covering an area of 11 square kilometres, situated around two kilometres to the east of L-A©¤rax tal-Mellie©¤a.

According to studies based on wind data collected so far, these would generate around 200 gigawatt-hours (Gwh) of electricity – which is about 10 per cent of what Enemalta produces every year, and the annual electricity consumtion of around 40,000 households.

Constructing an offshore wind farm is a lengthy process. A look at similar projects abroad show that a wind farm takes between six and eight years to construct, including time for studies and commissioning.

The Malta project, estimated to cost around €300 million, is expect­ed to be in place by 2016, four years before EU countries must generate 10 per cent of their energy through renewable sources. The wind farm alone would cover just over three per cent of this target.

This project forms part of the National Renewable Energy Action Plan, which aims to generate electricity not only from wind but also from the sun.

Dr Sant said studies were continuing on the environmental impact of the project and the suitability of the site.

These studies, overseen by the Resources Ministry, are costing the government around €300,000 and are expected to be concluded in about a year’s time.

Engineer Robert Farrugia, also from the University’s Institute for Sustainable Energy, said the institute had been collecting wind data from its station at Wied Rini since 1997, taking measurements of wind speeds at 10, 23 and 45 metres. This station is 220 metres above sea level while the one at L-A©¤rax is just 15 metres above sea level.

Dr Sant said the environmental assessments included geological studies on the seabed to determine whether the rock was strong enough to anchor turbines.

According to preliminary investigations, it appeared that the seabed was suitable, despite the presence of underwater caves.

Once these studies are completed, the developer will conduct further geo-technical studies on what kind of foundations the turbines require. The foundations alone are estimated to cost about 20 per cent of the total cost of the project.

The bigger the diameter of the turbines chosen, the slower the rotational speed of the blades, which would have a positive effect on aesthetics.

The high-tech designs of today’s turbines have resulted in much less noise.

Dr Sant said technology was improving drastically with modern turbines estimated to generate between 25 and 35 per cent more energy per year.

“These are more expensive but they give a better yield and would eventually result in a lower cost of energy,” Dr Sant said.

Studies conducted include:

• Effect of wind farm on birds and bats;
• Effect on marine ecology;
• Visual and noise impact;
• The impact of the rotating shadow of the wind turbines;
• The impact on the quality of the marine environment, including any possible pollution;
• Study on the possible archaeological remains;
• Impact on air traffic;
• Effect on communications, including mobile coverage;
• Impact on fishing and aquaculture.