This question has probably crossed peoples’ minds at some time or other especially when a windy day spoils one’s plans for a weekend picnic or day by the sea. There is the popular conception that the Maltese islands enjoy more than their fair share of wind.   Some persons go even further and ask why the wind isn’t being used for other purposes as in other neighbouring countries.  Truly, it is rather difficult to assess the quantity and quality of wind on the Maltese Islands based upon personal experiences and observations.  Historical evidence should however augur well if only due to the number of wind mills and water pumps which still dot our villages and countryside.  More concrete and definitive results may only be attained through a scientific study to assess the wind resource.  Only then, one can conclude whether re-utilising this free and clean source of energy is feasible and attractive.

Until few years back, the only long-term wind data available was that gathered by the Meteorological Office at Luqa for aeronautical purposes. A handful of studies had been carried out in the past using this data with conclusions varying from bright positive to downright bleak.  The main drawback with all such studies is that they assumed the Luqa wind conditions representative of the whole archipelago; an assumption which is being proved otherwise.

The Institute for Energy Technology, started a research project in this field with the primary aim of assessing the wind resource in the Maltese Islands. A wind monitoring programme was started in mid-1995 whereby several 10-meter masts were placed at different sites around the islands and instruments rigged to international standards. In some locations wind parameters are also being monitored at other levels above the ground; levels chosen to represent the operational height of modern wind turbines.  The data is being automatically recorded using state-of-the-art equipment which allows digital data handling and analysis.  Established computer software is used to process and evaluate the wind potential at different.  The results derived by simulation are further substantiated by measurement strategies at choice sites.

Based upon current research results one may immediately state that, as is the case of other countries, wind is site specific. Locations within a few hundred meters of each other may enjoy differing wind conditions.  These results illustrate the incorrect approach of using data at one site as representative of other sites on the islands.

These variations of wind parameters may be attributed to a number of factors such as the position of the site in relation to the prevailing wind direction, the presence of obstacles or rough terrain surrounding the area,  and the height at which the monitoring instruments are placed. Wind monitoring at 10 meters above ground level is the meteorological standard adopted worldwide. It also helps us compare the wind resource in Malta to that of other countries. Current research is also investigating the wind characteristics at heights of up to 45 meters as these correspond to the height of most modern small to medium-sized wind turbines.

One of the first wind turbines was a 100 kW Soviet machine located at Balaclava on the Black Sea coast in 1931. Wind turbine technology has made great strides since those early days both in terms of turbine conversion and operational efficiency.  Production and installation of increasing numbers of machines coupled by ongoing R&D is helping reduce production costs hence making wind energy conversion more attractive.  Countries like Germany and Denmark are leading the market in terms of installed capacity. To date there is 4,500 Mega Watts of installed capacity in Europe alone.  Over the last few years new markets are emerging in the far east such as China and India.

Modern wind turbines basically consist of  up to 3 blades (the rotor) connected to a generator via a step-up gearbox by means of a drive shaft.  The latter components are housed in a nacelle mounted on top of a lattice or tubular tower; whose function is simply to locate the turbine blades high enough to intercept enough wind. A control unit is also present in order to ensure a constant frequency output of 50 Hz, at all wind speeds. The electricity produced is then fed through a sub-station to the national electricity grid.  Modern turbines come in power ratings of about 50 kilo Watts (kW) to up to 1,500 kW.  The larger towers may attain a full 60 meters above ground level.  Smaller wind turbines of lower power ratings are also readily available ‘off the shelf’ although these are more suited for stand-alone applications such as in isolated homes or farms which are not supplied by the electrical grid.

From the current study, one can conclude that there are a number of areas on the Maltese islands which enjoy good wind characteristics. A single typical 600 kW turbine erected at one of these locations could easily supply about 1.5 million kW hours annually or enough electricity for about 400 households.

The main stumbling block with a number of these sites is that they are situated in the as-yet undeveloped  countryside.  Here arise the ever present problems associated with any  development of this type.  How far reaching would the environmental impact of wind generation be, and to what extent are we ready to accept such changes? These questions have already been faced by other countries implementing this technology, although one must keep in mind the fact that each country has its own particular problems for which specific solutions must be drafted.  One key factor must however be kept in mind before any decision is taken.  Adequate electrical generating capacity is essential for country like Malta.  The need for more and more power will continue in the near future if the trends over the last decades are followed.  What one should not miss out is the fact that conventional electricity generation is undeniably linked to environmental pollution.  A small but environmentally significant role may be played by a wind generation, a process which is safe, abundant and environmentally clean.

The Institute for Energy Technology offers consultancy services in wind energy for stand-alone and grid-connected wind turbines.

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