Enhancing Cypriot waste

Introduction

The page on the visit to Tridel SA, in Lausanne, Switzerland, shows how household waste can be turned into money, producing energy, reducing greenhouse gas emissions, reducing pollution and reducing the need for landfills. The purpose of this essay is to briefly examine whether the lessons learnt in Switzerland may be applied to Cyprus and with what modifications.

For the purposes of this essay, I shall call a waste value-enhancement power station, operating on similar lines to the Swiss Tridel, simply as a Waste Power Station or WPS.

Waste quantity

According to EIOnet, the last official EU figures for Cyprus were for 2003, at 518 000 tonnes, rising annually by about 18 000 tonnes/year, from households, services and commerces. Logically, this means the current quantity produced is about 590 000 tonnes. A revised figure is 571 000 tonnes for 2006 as reported in an unconfirmed newspaper article that, however, substantiates the trend. This is over four times the quantity treated by Tridel and could reasonably be expected to generate at least 80 MW, probably 100 MW, of electrical power by the time one adds organic industrial and building waste. This is almost 10 per cent of the peak electricity demand and all this from a fuel costing almost nothing, other than the price of collection and delivery. The quantity would be further increased if fly dumping were more strictly controlled and garden rubbish were also accepted.

This quantity of waste is equivalent to about 150,000 tonnes of fuel oil. This is the equivalent cargo of a large range tanker which would be too big to go through the Suez Canal! Burning this quantity of heavy fuel oil would release half-a-million tonnes of fossil carbon dioxide, so opting for this type of renewable energy would favour Cyprus' chance of meeting its Kyoto Protocol and European Union obligations.

Let's put this another way: if an average car has a fuel consumption of 10 l/100 km, this would be equivalent to every car, SUV, pickup and light van in Cyprus doing over 9 000 km less each year, in terms of fossil carbon dioxide emissions.

On the basis that compacted household garbage weighs 481 kg/m³, (figure obtained from the Internet), the volume of 590 000 tonnes would be over 1.2 million m³ of waste currently landfilled each year. If its value were enhanced by using it well, over 1 million m³ would no longer need to be landfilled. Furthermore, the remainder would be essentially cinders which would not emit methane nor attract vermin, such as rats. I estimate the methane emissions of landfilling 590 000 tonnes of waste would be at least 35 000 tonnes/year, probably a lot more. This would be equivalent to about 875 000 tonnes of carbon dioxide, as the Global Warming Potential of methane in Cyprus would average about 25 with the low free hydroxyl radical concentration in summer. To this should be added another 50 000 tonnes of carbon dioxide emitted directly from landfills, totalling an equivalent of 925 000 tonnes. To obtain the overall benefit, incinerating the waste will cause emissions of carbon dioxide, some of which will be captured by the scrubbing process and subsequently converted to solid waste by the addition of limewater. As a first estimation, the overall advantage of incineration in a PWS, compared to landfilling, would be approximately equivalent to 450 000 tonnes of equivalent carbon dioxide.

If we add the savings of greenhouse gas emissions from landfills to that of not having to import 150 000 tonnes of fuel oil to generate the same amount of electricity, this would be almost equivalent to taking all the Cypriot cars off the road altogether, some estimated 950 000 tonnes of equivalent carbon dioxide.

Waste quality

Cyprus, in the EU, along with Malta, is in an unenviable position. It is required to recycle paper, cartons and other organic wastes yet its size does not justify such recycling within the country and exporting such low-value waste is not economically viable. It would therefore make sense to recycle it by converting it into energy which can be sold, rather than exporting it in containers at a loss. The economically viable recycling, such as aluminium (especially drinks cans in the Cans for Kids campaign) and PET bottles can continue to be exported, but all other plastics can be put in with the household waste, because they can be a valuable fuel.

This would solve the dilemma of most of Cyprus' waste, by generating electricity from it.

Potential sites

If one or more WPS were to be installed on the island, the question is where? It must be borne in mind that a WPS is non-polluting and could be installed in any industrial zone. In order to keep transport of waste to a minimum, it should be reasonably close to the catchment areas, which would be about proportional to the population, in terms of waste tonnage.

The population of the Republic is about 779 000 (2006 statistics) divided, by District, into 43 000 for Famagusta (Ammochostos, yellow), 75 000 for Paphos (Pafos, orange), 130 000 for Larnaca (Larnaka, lilac), 224 000 for Limassol (Lemesos, rose) and 307 000 for Nicosia (Lefkosia, green).

The bigger the WPS, the lower the capital cost per MW of energy. A single station at, say, somewhere in the Alambra region, in the centre of gravity of the population distribution, would therefore seem a logical choice. However, a WPS produces useful heat, as well as electricity, and it seems doubtful whether this heat could be logically exploited in this region. I therefore suggest it would make sense to build two identical 50 MW electricity WPSs rather than one. This would have the advantages that planning costs would be lowered, a technical breakdown of one would still leave half the capacity of waste enhancement operational and that spare parts would be interchangeable, as well as reducing the amount of road transport and its concomitant pollution. In the event that the Turkish Military Occupied area were to be reunited with the Republic, a third station could be built at a suitable site.

Assuming two were to be built, where would the ideal sites be? I suggest near Latsia for one and Vasilikos for the other. The first would be ideal for Nicosia District and the second for the other districts, minimising transport and the associated pollution. The design of a modern WPS allows a distribution of heat and electricity to be balanced. At full electrical output, the heat is low and vice versa. It is therefore possible to manage the balance, provided that we have a use for the heat. At Vasilikos, there would be two ideal possibilities for heat use, which I estimate to be adjustable between about 50 MW and 150 MW for a 50 MW alternator. The first is to use it for the proposed land-based regasification plant that will need large quantities of thermal energy. The second is to use the excess heat to distil sea water, to help mitigate the water crisis on the island. There are even other potential uses. The Latsia plant is less evident as to how the heat can be used. Hot water for the General Hospital would be an easy solution, as would heat for the Pittas factory, the brewery and other industries along the B1 road. The heat would be distributed by pressurised water at 200°C in insulated pipes in a closed circuit, feeding heat exchangers where needed. Even individual habitations could be centrally heated in winter from this source.

There is one advantage to be considered for both proposed sites: the existing proximity of high tension lines would obviate the need for expensive connection charges.

Rubbish collection

Household garbage could be collected, as usual, in compacting waste collection vehicles (WCV, similar to the one shown in the Tridel page). However, the quantity collected by a single WCV would be too small to justify transport over long distances. It would make sense to have special leak-proof 12 m containers into which compacted rubbish can be transferred at a site in each town and large village or cluster of smaller villages. These containers, holding typically five or six times the volume of a single collection vehicle, could be transported by articulated trucks to the nearest WPS, thus reducing the amount of heavy road traffic and pollution on the motorways. Organic industrial waste which could be assimilated to a 60 litre rubbish bag could be treated similarly. Larger waste, such as planks of wood from building demolition sites, would need to be treated specially, at extra cost.

The cost of implementation

WPS plants are not cheap. As a first estimation, the cost breakdown, in millions of euros, of implementing two identical 50 MW electricity plants would be:

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