Independent sustainability managers are calling for a more accurate assessment of air quality linked to the Delimara power station.
Covered by an environmental permit since 2007, the Delimara power station (DPS) switched from diesel to heavy fuel oil with the considered approval of the Malta Environment and Planning Authority in 2011.
It was clear that diesel was a better fuel for the environment than crude oil. Yet assurances were given at the time that pollution abatement equipment would keep the predicted emission limit values in line with EU legislation. In June, the permit to use heavy fuel oil was extended by nine months to allow time for more data gathering and monitoring.
Oil industry news portal Argus commented at the time:
“On a long-term basis, and given the stress Malta has placed on carbon reduction within its energy sector policy, fuel oil’s future as a power generation source in the country is limited – regardless of Mepa’s ultimate decision.”
Heavy fuel oil (HFO) is a black viscous residue that does not burn easily. The cheapest refinery product, it is what is left after extracting petrol, diesel, jet fuel and other components from oil.
The treacle-like fuel has to be heated to a high temperature so it will ignite on injection into the power station burners. It does not really come cheap, as special methods are needed to burn the oil and control its emissions.
With the trial period for the use of HFO at the power station now extended to next March, an independent consultancy has expressed concerns over technical details on prevention and control of air pollution.
For the purpose of studying impacts from the use of HFO by the power station at Marsaxlokk Bay, the authority contracted an outside party to evaluate air and other monitoring data in the vicinity of the power plant.
University of West England’s Air Quality Management Resource Centre (AQMRC) was given the role of analysing air quality data from Marsaxlokk and Birżebbuġa. They have been looking at continuous stack monitoring data, meteorological data and ambient monitoring data from Mepa to determine whether emissions from the Delimara power station during the period of HFO use is contributing to pollution levels over and above legal limits.
The controversy rages over how much recorded particulate dust and other pollutants can be fairly be pinned down to the power station and how hidden causes can be tackled, on and off site.
Setting a baseline for measuring pollution is a sensitive affair. Set it too low and spikes above the red line are likely to be more apparent – along with possible penalties if the situation persists. Set it too high and it may become an over-tolerant smokescreen when pollution levels soar dangerously high.
This year’s measurements are to be compared to monitoring data collected from 2009 against which the impact of the DPS plant emissions are set. Typical ambient backgrounds are represented by monitoring stations at Għarb (rural), Corradino (industrial), Msida (roadside) and Żejtun (urban).
Comments were submitted during a public consultation for the AQMRC study on the impact of using HFO at the Delimara power station. Consulting environmental engineers and sustainability managers Simon Abela and Scott Micklasusis found “elementary shortcomings that should be addressed if the contractor is to perform an accurate assessment”.
Their submission to Mepa reads:
“While the effort to assess the Delimara Power Station’s contribution to air pollution is commendable, certain technical shortcomings in the currently ongoing study threaten to seriously mis-measure the emissions of the power station. All of these shortcomings can be addressed, as we have outlined in our proposed action plan.
It may be safely assumed that the ports generate more pollution than does Delimara power station- Consulting environmental engineers and sustainability managers Simon Abela and Scott Micklasusis
“We would like to assist in addressing these issues, and we invite interested parties to contact us for a more thorough, detailed discussion of the extent of these problems and how they should best be approached.”
An upgrade was recommended from basic particulate monitoring equipment to other devices more suitable to record and track pollutants. The basic instrument currently being used to monitor dust has come under criticism:
“Although this device is handy for simple particulate matter monitoring and recording, there are other devices more suitable to collect, record and track pollutants other than particulate matter.
“Higher, cost-effective devices track and record pollutants which pose greater health hazards than do particulates. These other pollutants can be toxic and carcinogenic and we can expect to find them in the Delimara Power Station exhaust plume. We need to measure them.”
The Bristol-based university’s HFO impact study has also come under fire for not making any reference to the make and model of the diesel engines, date of manufacture, horsepower and other criteria necessary for a baseline assessment.
“Without such data, the environmental professional cannot determine whether engine inefficiencies are causing sub-optimal performance. How can Delimara power station reduce the levels of a given pollutant if we never bother to identify that pollutant’s efficiency causes?”
On ambient pollution it is noted that the Malta Freeport and the airport are significant contributors to area pollution levels, yet the current study appears to ignore them.
“The study is, apparently, structured in a way that makes it impossible to differentiate between pollution originating from DPS and pollution resulting from these ports. If policy decisions were to be based on the resulting assessment, power plant operators could find themselves in the impossible position of pursuing air quality targets that even a zero-emissions power plant would never achieve, because port pollution is being neglected.”
“The Malta Freeport and the Malta International Airport (MIA) generate pollution from the combustion of gasoline, diesel fuel, and jet fuel by cars, trucks, ocean vessels, aircraft, and other vehicles and equipment.
“In fact, it may be safely assumed that the ports generate more pollution than does DPS. If we are to accurately measure the emissions of DPS, then we must account for these ambient effects through an emissions inventory of both ports.”
Also advised in the submission, made during the public consultation which closed on September 5, is an inventory for the nearby Ħas-Saptan fuel storage area to allow for an accurate assessment of the DPS and “help avoid misguided, wasteful remediation activities”.
“The variability of HFO makes it impossible to judge an engine’s performance through smokestack emissions alone. A smokestack measurement of, say, 4.5 per cent sulphur may be excellent, or it may indicate inefficiencies that should be addressed.
“So far as we are aware, the current study is not taking these nuances of HFO into account.”
For a true baseline assessment it was recommended that measurements be taken in rural areas where no combustion engines are present, such as Comino and remote parts of Gozo.
Other areas of concern are fugitive emission of HFO from ships to above-ground storage tanks, industrial permitting of large combustor engines at MIA and the Freeport, and the need for a sulphur recovery tower.
Mepa has been urged to be vigilant for unscheduled maintenance, start-up and shutdown activities, and emissions from soot blowing at the power station.
The final comment from Abela and Micklasusis points to the lack of an environment professional to monitor the DPS on a daily basis.