Patrick Zahra (The Sunday Times, December 13) is mistaken when he claims that the data regarding emissions from the new generating plant are "unguaranteed data forwarded by BWSC". The emission levels are stipulated as mandatory requirements in the contract and are, in fact, guaranteed by BWSC.
Dr Zahra is also mistaken in his belief that the new plant will rely on 'filters' to reduce emissions. In fact, different systems will be used, and only one is a 'filter', which will be used to reduce dust emissions. The proposed exhaust gas cleaning systems are most definitely not 'prototype' and consist of well-proven technology, both on diesel engines and on other combustion plants.
For nitrogen oxide (NOx) reduction, the plant will use Selective Catalytic Reducers (SCR), which operate by injecting an ammonia-rich reactant in the exhaust gas stream, passing this mixture over a catalyst, thereby reducing NOx, which is converted to harmless nitrogen and water. This established technology has been adopted on combustion plants for over 20 years and has also been used on diesel-operated power stations, ships and on heavy commercial road vehicles over the past years.
For the reduction of sulphur dioxide (SO2) the plant will use a dry type flue gas desulphurisation unit using sodium bicarbonate as a reactant injected in the gas stream, and bag filters which will also trap dust produced by the fuel combustion. Again, this is an established technology (introduced during the mid-1990s) and has been used on generating plants, chemical plants and waste incinerators. The only thing that is 'prototype' is the combination of these technologies in a diesel engine plant.
All mechanical plants are subject to wear and tear, and this affects efficiency and power output. Although the unabated emissions of SO2 and cardon dioxide (CO2) may tend to increase with wear and tear (all other things being equal), the equipment is designed in such a way that the abated emissions will still remain within stipulated limits.
Furthermore, all the emissions cleaning equipment is designed in such a way that its capacity can be increased if emissions limits are further reduced in the future.
The only emissions that would increase marginally as a result of a drop in the plant's efficiency would be those of CO2 which, apart from their effect on global warming, have no direct harmful effect on humans.
As regards marine, land and fauna, these issues were analysed in the EIA report which we invite Dr Zahra to read.
In addition, the environmental impact assesment, contrary to his suggestion, is not based on assumptions, since the emissions and performance data appertaining to the new plant are contractually guaranteed.
The recent ECJ judgment concerns part of the Delimara power station, namely the steam plant, constructed under phase 1. The plant is already compliant with EU directives for emissions of SO2, where the emissions are 70 per cent of the limit, and dust, where the emissions are 50 per cent of the limit. A tender for modifications to ensure its compliance with limits on emissions of NOx, which are currently 20 per cent above the limit, is being evaluated.
All other equipment at Delimara is compliant.
The sulphur content in fuel oil is regulated by law. Enemalta is already using 0.7 per cent sulphur fuel oil, less than the 1 per cent legally permitted. Dr Zahra's comments on what he supposes will be Enemalta's actions are based on nothing more than personal opinion.
It is a mistake to believe that other developed countries are moving away from fuel oil. The use of fuel oil in most of the larger countries was always limited, as fuel oil is uncompetitive with coal, which still fuels most large developed countries' electricity.
The combustion of coal generally results in higher emissions than fuel oil unless treated in a similar manner to the emissions from fuel oil burning plants, and fuel oil is/was generally reserved for use on generating plants with more flexible operating characteristics.
Heavy fuel oil is still in worldwide use in the marine industry and for electricity production, especially in small islands which, like Malta, have to rely on imported primary energy sources.
The new plant will reduce the amount of greenhouse gas emissions per unit of electricity generated when compared with any other plant presently installed at Enemalta, and will also contribute towards achieving the national emissions reduction targets.