A private company has proposed to set up a 460-metre diameter floating wind farm off Malta’s coast, with a potential to generate 54 megawatts of electricity
The Malta Environment and Planning Authority (Mepa) is reviewing submissions made during a public consultation period, following a Project Description Statement (PDS) submitted by Hexicon Malta Limited regarding an ambitious 460-metre diameter floating wind farm in Maltese territorial waters. If the project, planned to be ready as early as June 2014, is given the green light, it would not only be the largest such complex in the world, but according to the PDS, it would also meet the 10% renewable energy target by 2020 set by the EU.
This substantial, undisclosed foreign investment is also expected to generate up to 200 jobs during the construction period, and a further 10 once operational.
According to Hexicon AB, the Stockholm-based company is claiming that this giant hexagonal wind farm has a potential to generate as much as 54 megawatts (MW) of electricity. The nominal combined generation potential of Malta’s two power stations at Delimara and Marsa is of 571 MW.
Although the PDS dates back to 11 May last year, the period of public consultation was officially announced in the Government Gazette on 28 February and closed on 17 March. To date, no application by Hexicon has been submitted to Mepa.
A spokesperson for the Ministry of Resources and Rural Affairs (MRRA), explained that the project is a totally private initiative and has no links with the pilot project at is-Sikka l-Bajda, limits of Mellieћa. However the government remains a very interested spectator as this proposal for a gigantic off shore wind farm, may prove to be beneficial in reaching the ambitious EU targets if other avenues being sought lead to nowhere. Thus the government might seriously consider the option of buying clean energy at a fixed rate, without the hassle of investing heavily himself.
According to the PDS, Hexicon Malta is proposing three particular sites for this wind farm, the preferred one being 11 nautical miles off the eastern coast of Baћar iċ-Ċagћaq, approximately 20 kilometres off shore. It is also proposing a 132 kV under water cable via Qalet Marku linking the wind farm to a terminal station located near Magћtab, managed by ABB.
The proposed structure includes no fewer than 36 turbines — a 120-metre-tall horizontal-axis 6.5MW machine on each of its six corners, and a further 30,500kW vertical-axis units.
The Swedish company is already looking at similar projects in Cyprus and Sweden. Though one of the most crucial factors is the water depth of the proposed locations, the success or not of tapping EU funds especially dedicated for private initiatives in favour of clean energy generation may have the final say.
The company has its A480 model concept up for funding under the NER300 programme — a new-technology financing scheme managed jointly by the European Commission, the European Investment Bank and member states — with a decision due this year. It is believed the company is seeking a formal endorsement by the Cabinet as part of its submission to the EU.
Hexicon business development director Percy Sundquist was reported saying that “It depends very much on what each country or indeed a given government department will provide in terms of support [on top of the NER300].
He explained that “the main average wind speeds off Scandinavia versus the Mediterranean are very different. We’d like to use a Vestas [horizontal-axis] unit if we were looking at a development site with lower average wind speeds, but Bard, Siemens and REpower would be the manufacturers we would favour for higher-wind-speed sites.”
Hexicon’s “preferred choice” to supply the vertical-axis turbines is Swedish company Vertical Wind.
“The key idea is that you have four turbines that get clean wind 365 days a year, whereas many traditional wind turbines get this 60-70 days a year and spend the rest in the ‘shadow’ of other towers,” Mr Sundquist said.
“Then we have two aft [rear] turbines getting 45% efficiency and then the vertical-axis units [which are omni directional] boosting capacity up to 54MW.”
A modified version of the design bolts on 27 wave-energy converters for an extra 15MW.
According to the PDS this project will meet the increasing demand for electricity generation at a more competitive rate than provided by oil based generators. Among other positive spin offs, there is mention of a possible use of the floating platform for desalination and fishery purposes in future.
Potentially the most controversial aspects of this whole project might prove to be the aesthetic and the environmental ones. According to the PDS, one of the major stumbling blocks so far in exploring possible sites for fixed monopole wind farms is that water depths less than 20 metres are too close to land, and are of sensitive ecological importance. Thus Hexicon is claiming that the floating platform proposal is an innovative and a much more viable way to explore off shore wind farms for Malta.
The Swedish company is binding itself to consult with all the relevant local agencies including the Fisheries and Control Division in MRRA, Transport Malta, Malta International Airport, Malta Air Traffic Services, Malta Tourism Authority, Malta Resources Authority, Malta Communications Authority and the Armed Forces.
At the exact location of the proposed Hexicon platform water depths vary between 100 metres and 150 metres, which is well within the capacity of the platform. This has an expected lifetime of 50 years while the power generation units are expected to last about 25 years. Vertical wind towers will reach a height of 35 metres, while turbines will be fixed in a hexagonal shape with six horizontal turbines on each node. On the centre hull pipes, 30 vertical towers will be placed, five on each pipe. According to the PDS, the maximum height of the turbines is 130 metres. Basically the technology behind this platform is very similar to that of oil rig installations, and includes a helipad facility.
To mitigate the visual and acoustic effects the PDS lists several measures. On the visual aspect it is claimed that the platform would have a minimal impact due to its distance from the shore line. However the design of night time lighting needs to be carefully studied to minimize as much as possible, the visual impact at night.
Regarding possible noise pollution, the PDS claims that due to technological improvements and the considerable distance of the platform from land, the impact will be negligible.
Regarding the impact on birds, which was a source of controversy in earlier proposals, the PDS dedicates only one sentence stating that the design will be carefully selected to minimise any possible impacts on local and migratory birds.
Hexicon plans to carry out this project in two phases, the first over a 21 month period during which the equipment will be manufactured and transported on site. Phase two will consist of the assembly and building of the platform, which is estimated to take about six months and its connection with the interconnector cable linking Malta to the European Grid via Sicily.
From a technical point of view the whole platform can rotate 360 degrees and be anchored within 30 minutes. The PDS claims it can withstand rough seas, with waves of up to 25 metres. Regarding possible locations for this projects among the factors being considered are water depth, wind speed and direction, tides and the geology and morphology of the seabed.
Some Facts and Figures
Company: Hexicon AB, based in Stockholm
Time frame: Earliest operational date is June 2014
Budget: Undisclosed but much depends on EU funding
Size: 460 metres diameter and reaching a height of up to 130 metres
Proposed Site: 20 kilometres in the North East of Malta
Power generated: 54 Mega Watts
Jobs: 200 during construction and 10 when operational
Suggested callouts:
The government remains a very interested spectator as this proposal may prove to be beneficial in reaching the ambitious EU targets if other avenues being sought lead to nowhere
The key idea is that you have four turbines that get clean wind 365 days a year, whereas many traditional wind turbines get this 60-70 days a year and spend the rest in the ‘shadow’ of other towers
At the exact location of the proposed Hexicon platform water depths vary between 100 metres and 150 metres, well within the capacity of the platform, which has a lifetime of 50 years