The first half of the editorial “A victory of dubious merit” (TMIS, 28 November) is a timely piece on the Delimara Power Station extension (DPSe) saga; but when the subject switches from the EC ‘investigation’ to technical aspects, it goes downhill.

Major ‘government’ decisions are often not seriously scrutinised in or out of Cabinet. When deciding to switch to natural gas in our power stations, not much thought seems to have been given to the size and cost of infrastructure required to ensure a large, steady supply of natural gas until the DPSe countdown had started – by then it was far too late. Yet in the parliamentary debate on climate change in January 2009, Minister Gatt – in the presence of Jesmond Mugliette, incidentally – loudly assured us that we were going to get natural gas by pipeline from Gela, in Sicily. He did not give a timeline, however, and has not given one since.

I feel that the choice of technology – eight piston engines against three large turbines – was the correct one for our grid. The point of contention has been the fuel: the turbine ensemble (a larger version of the one in use at DPS since 1999) can take gasoil (available) or natural gas (not available), but not Heavy Fuel Oil (HFO). The piston engines (eight of 18MW each) can take diesel or HFO and could be expensively (€27 million) converted to natural gas.

The choice of HFO may indeed be “the worst thing for the environment but the best thing for the state coffers”. Certainly, the environmental and public health risks are high. The SO2-NOx-dust removal equipment is an untried combination; the disposal of 30t of hazardous waste per day cannot be taken lightly, and the daily tonne of HFO sludge cannot be forgotten. The public cannot have great expectations of the smooth operation of the equipment simply because, as the NAO report puts it, “The [Enemalta] Corporation’s Senior Management, under oath, confirmed their full confidence in the successful outcome of the project.” After all, these are the same people who, when faced with the relatively small problem of Marsa fly ash storage, simply switched off the precipitators and dumped the stuff on us. And by the way, who has ever heard of people, least of all engineers, taking oaths on such things?

As to the benefit to state coffers, this is an area where ministerial action has been at its most muddled. In the heat of the action, Minister Fenech proclaimed, without any explanation, that the use of gasoil instead of HFO would put up electricity bills immediately by 30 per cent. At the same time but with much less fanfare, Enemalta said that the unit cost for gasoil would be 24 per cent higher than that for HFO.

A close look would show that both figures are far too high. The DPSe will provide about 1/3 of total generation. Taking gasoil as 60 per cent more expensive than HFO, the average price of a unit, on fuel costs alone, will go up by 18 per cent. But DPSe has another virtue: the piston engines are rated at 46 per cent efficiency, as against the 30 per cent average of Marsa. In simple terms, DPSe will use 46/30 (1.5) times less fuel than Marsa to generate the same quantity of electricity. That brings the increase in the average price of a unit to just over two per cent, hardly likely to break the bank at Enemalta.

But there is more. The major expense of de-SOx and sludge (but not the minor one of de-NOx and dust) will be eliminated, as gasoil has far less sulphur than HFO. Enemalta, and all of us, might actually be better off financially – the lowest public denominator of course.

Now Minister Fenech and Enemalta are quite free to pick holes in the above. What they are not (ethically) free to do is to keep their mouths shut and continue with a HFO-fuelled DPSe.

E.A. Mallia

ATTARD