I do not concur with Mr Robert Ebel’s scepticism that Malta cannot reach 10% renewable energy by 2020 (‘Alternative Energy: Don’t hang your hopes on it’, 26 October).
While acknowledging that we have to start from ground zero (mainly attributed to government’s bias against renewables during the last four years), I am convinced that the 10% RES (renewable energy sources) by 2020 target is achieveable – by using a mix of renewable energy technologies and approaches, and not just focusing on a single technology. Indeed, it would be foolish to put all one’s eggs in one basket.
Unfortunately, to date, all discussion on renewables in Malta has focused on wind and solar (predominantly PVs). Several opinion writers have failed to acknowledge the huge potential of waste-to-energy processes as a means to attaining the RES target. Since 2001, I have been actively lobbying for the introduction of a waste treatment process referred to as Anaerobic Digestion (AD) in Malta. The process is relatively simple: organic waste is fermented (digested) in an enclosed tank (the digester) to produce biogas. Biogas is 65% methane, a fuel which can be used to drive an engine, which in turn drives a generator producing renewable electricity.
Malta is ‘blessed’ with a high fraction of biodegradable waste in our municipal waste stream. Whether we like it or not, biodegradable waste will have to be treated before landfilling – an EU requirement.
Treatment of municipal waste through anaerobic digestion kills two birds with one stone: the waste is treated according to the Directive, and a substantial amount of renewable electricity is generated in the process. A win-win situation, if there ever was one.
I was therefore satisfied to note that Wasteserv has incorporated an AD process in their upgraded Sant’ Antnin Solid Waste Treatment plant. The Sant’ Antnin plant will treat a third of Malta’s municipal waste stream, and generate approximately 0.3% of Malta’s electricity from the AD process. The waste treatment plants to be built to treat all of Malta’s waste will push this figure beyond the 1% mark.
The animal husbandry industry in Malta generates huge amounts of manure, all of which is digestible and an ideal feedstock for biogas generation. Moreover, practically all animals in Malta are housed, thus facilitating the collection of manure; additionally, transportation distances (from the farm to the treatment plant) are relatively short. Selected bio-wastes such as wastes from tuna-farming activities, abattoirs, food processing industries, etc., will further increase the biogas generating potential, while adequately treating these waste steams to EU standards.
It is estimated that another 1.5% of Malta’s RES can be achieved through digestion of manure and these organic (and problematic) waste streams.
The digestion of sewage sludge from Malta’s new sewage treatment plants will roughly generate another 0.3% of Malta’s RES, which energy will be used to offset the sewage treatment plants’ energy needs.
And this is not all. The non-digestible fraction of municipal waste can be converted to what is commonly referred to a Refuse Derived Fuel (RDF). The conversion of RDF into useable energy can generate almost 2% of Malta’s RES.
That’s almost 5% of our RES target being attained – simply from appropriately treating our waste.
This is not intended to belittle the potential of wind or solar energy. Indeed, given the exhorbitant of fossil fuel energy in Malta, this country needs every drop of renewable energy it can harness. And for our own sakes, we should be planning to achieve (and exceed) the 10% RES target well before 2020!

Marco Cremona
Mosta

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