Some time before the Christmas break, Professor E. Mallia harshly criticised speculation that a 25 per cent reduction of Malta’s fossil fuel consumption for the generation of electricity could possibly be achieved with land-based wind turbines (Missing the wind for the rotors, TMID, 14 December).

The starting point behind this speculation is, firstly, that wind conditions in Malta, though not ideal, are probably sufficient to make wind power sustainable. Secondly, one third of the island is densely populated and the remainder is relatively sparsely populated. A substantial portion of this remaining area is elevated, exposed and virtually uninhabited.

Thirdly, an application for planning permission for a wind farm on Marfa Ridge is currently languishing in some government office or other. This wind farm was to consist of 12 turbines with rotor diameters of 92 metres, each with a potential of 2.75 megawatts.

The calculated mean wind speed at pylon height was 7.5 metres per second. The annual output of such a wind farm was projected at 55 gigawatt hours which, I understand, is equivalent to five per cent of Malta’s total electricity needs. These turbines are of an advanced design and are capable of converting wind into electricity more efficiently and of operating at lower wind speeds.

If this wind farm is installed, the 12 turbines will be erected over a strip of uninhabited land approximately two kilometres long and one kilometre wide. This wind farm thus requires a minimum of two square kilometres (approximately half a square mile) to allow adequate distances between turbines. Let us be generous and allow a square mile for five hypothetical wind farms of 12 turbines.

One square mile might sound like an awful lot of space, but there is a crucial difference between a wind farm and an equally large development such as, say, a golf course or a new residential area.

Whereas the entire terrain taken up by a golf course or residential area is irrevocably destroyed, the area that is disturbed when wind turbines are installed is minimal. In the case of the wind farm proposed for Marfa Ridge, the area which has to be disturbed would probably be less than the usually quoted three to five per cent of terrain, since the turbine foundations will be embedded in solid rock.

Apart from the unavoidable visual impact, the turbines will not affect the quality of life for man or beast in the vicinity and life will continue undisturbed beneath them.

The challenge is therefore to find five square miles in suitable exposed sites in Malta and Gozo, sufficiently far from human habitation, on which an aggregate of turbines equivalent to five of the proposed wind farms might be built. The huge obstacle is the very serious visual intrusion inherent in wind energy; there is no question that these leviathan structures will probably be visible all over the island.

If a total of 60 turbines were to be erected, their output would theoretically approach 25 per cent of Malta’s requirements. I agree that this is decidedly optimistic. But then I still have trouble with accepting Prof. Mallia’s assertion that not more than around five per cent of Malta’s electricity generation can be met by onshore wind power.

I therefore still maintain that what I said is not as inconceivable as Prof. Mallia made it out to be, and I emphasise again that my suggestion was stated cautiously as being “not necessarily beyond the realms of possibility”.

Maybe the truth lies somewhere between my speculation and Prof. Mallia’s figures. For instance, the province of Ostfriesland in Germany derives more than 50 per cent of its electricity from wind turbines. Denmark also currently generates around 20 per cent of its electricity with wind, and plans to increase the share of wind power. Both Ostfriesland and Denmark are sparsely populated areas surrounded by shallow waters.

Unfortunately, Malta does not enjoy either of these luxuries, so our choice is limited. When the use of oil becomes an unaffordable luxury, and push comes to shove, exceedingly visually intrusive wind turbines might have to be the price to pay for reducing Malta’s dependence on oil, as long as photovoltaic energy remains too expensive an alternative.

No one will deny that the question of seeking ways to exploit renewable energy is becoming more urgent as time goes by.

The mere fact that the subject of my letter was wind energy did not imply that I regard wind energy as the only solution to energy problems. There is no question that there are other technologies for exploiting renewable energy. After all, the combination of PV and wind complement each other very well.

As things now stand, land-based wind energy is currently the most economically sustainable form of renewable energy open to us. If other means of harnessing renewable energy become affordable, the turbines can be removed, leaving virtually no trace. This is the supreme advantage of turbines.

In particular, when a reduction in the prohibitively high cost of photovoltaic power eventually makes this form of power worthwhile – or if some other technology becomes available – some or all of the of the turbines can be removed.

In the absence of systematic measurements of mean wind speeds at likely sites over a sufficiently long period of time, the only way to establish the place for wind energy in Malta is to build at least the single wind farm, which was originally proposed for Marfa Ridge, and see how it performs.

We will also find out if the visual intrusion is acceptable If, on the other hand, there are hard data which suggest that there is, in general, insufficient wind to generate enough energy to make land-based wind power viable in Malta, then I apologise to Professor Mallia for trespassing on his area of expertise and ask readers once more to forgive me for continuing to allow myself to be carried away by my enthusiasm for exploitation of renewable energy. The global rate of growth in wind power is currently over 30 per cent. The unit cost of wind-generated energy is decreasing dramatically (while the price of oil is doing the opposite).

In the meantime, Malta stubbornly persists with her total dependence on fossil fuel for generating electricity. As long as this situation is allowed to continue, people will have to put up with inexorable rises in electricity bills over the coming years.