The interconnector cable between Malta and Sicily is the longest of its type in the world.Challenges and opportunities in energy and transport was the theme of the this year’s annual conference of the Chamber of Engineers held last month.
The conference coincides with a new era. For the first time, the Maltese electricity grid is looking at a possibly wide range of new energy sources. Joining Malta to the European grid was aimed at improving security of electricity supply for consumers and boosting Enemalta’s financial position. At the same time, a number of EU directives had been pushing for the closing down of Marsa power station and switching to generation of power generation with a lower carbon footprint.
Laying an interconnector cable between Qalet Marku in Malta and Marina di Ragusa in Sicily called for an environmental impact assessment for each of the sites where the cable came to land. On the Ragusa coast the cable was planned to come ashore between a beach and a nature reserve, then run to a connection point 19 kilometres inland. Engineer and project manager Joseph Vassallo described how measures were taken to avoid damage to the marine environment in the process.
A 500-metre-wide corridor along the sea bottom was surveyed for Enemalta and samples taken to establish the benthic community of the seabed. Environmental requirements were “more complicated” on the Italian side, with concerns running high over the effect of trenching on posidonia sea grass meadows offshore.
Although a permit to begin works on the Malta side was issued in 2012 the Italians asked for extra studies. In a decree known as a ‘prescription’, the Ragusa side called for mitigation of any damage to the local sea grass. It was decided that this could be met by relocating the posidonia matte, although it would not be acceptable to site it off Palermo or another distant coast since it may not have been compatible with the posidonia growing at other locations outside the vicinity. The cable also had to be re-routed around the Vega oilfield and also a World War II plane wreck found on the sea bed.
On the Sicilian side, the project met with some objections but the protestors turned out to be mainly local fishermen engaged in illegal fishing activities such as bottom trawling.
The cable is the longest of its type in the world. Globally, this technology is also being considered for connecting distant offshore wind farms to distribution points on land, although unfortunately this will not be happening in Maltese waters any time soon. Executive director of generation and distribution at Enemalta, engineer Jonathan Scerri noted that, owing to “lack of short-term feasibility”, wind prospects have been put aside in favour of photovoltaics to meet 2020 EU targets.
Back in 1959, it was a cable connecting Gozo to the Malta grid at Ħondoq ir-Rummien that was chosen as the more feasible option, ruling out any further expansion of the 10-year-old Gozo power station and avoiding further environmental impacts on the island.
Since then, the energy corporation has come a long way, meeting operational challenges brought by the introduction of renewable energy to the grid.
Although the two-way interconnector cable can carry electricity both ways, any Malta surplus is mismatched with Sicilian demand so that exporting power to Sicily will not be feasible. Renewable energy generation may have to be curtailed when operating in ‘islanded’ or isolated mode, which can be intentional but also accidental. When renewable energy is not producing electricity in Sicily the price of electricity via the interconnector could be quite costly.
The chamber’s president urged government and the private sector to work together to provide smart travelling, which would provide efficient ways of travel that are socially and environmentally aware
Installation and testing of a photovoltaic array near Comino is a project aimed at comparing the behaviour of floating PVs with a similar set-up on land. Engineer Stephen Sammut explained the challenges to the flexible thin-film panels, which could face salt caking and algal growth. Since the performance of solar panels can be reduced in high temperatures, the sea cooling effect on slightly submerged or neutral buoyancy panels could be an advantage. Issues of durability, corrosion, mooring and transmission of data are still being tested.
An evaluation of different technologies for energy production was given by Fulcieri Maltini. He spoke of the upcoming climate change conference in Paris at the end of the year and the city’s plans to ban diesel fuel by 2019. While much is said about carbon dioxide, methane gas has a lifetime 100 times greater and is one of the worst greenhouse gases. These gases act by ‘thickening’ our atmosphere and reflecting heat back to the Earth. A tailpipe emissions target for 2020, set by the EU, poses a significant challenge.
Engineer Norman Zammit, the chamber’s president, urged government and the private sector to work together to provide smart travelling, which would provide efficient ways of travel that are socially and environmentally aware.
Planning for driverless vehicles was the subject of a presentation by engineer Matthew Clarke. We cannot simply go on building more and more roads to try and deal with traffic congestion. Ownership is expected to shift away from a strong reliance on the private car toward public transport and journey sharing. Google sees its self-driving car technology as the autonomous taxi of the future, roaming cities to pick up and drop off passengers on demand.
In Britain, autonomous vehicles (AV) are already at trial phase, operating in complex and unpredictable pedestrian environments in Greenwich, Milton Keynes and Bristol. Some predict that, with more products on the market, infrastructure providers will build the street environment around AVs, reducing congestion and the need for signs or signals, also closing roads that are no longer needed.
Intelligent transport systems can adapt traffic light timings to varying traffic conditions and aid dynamic charging so that parking charges go up or down as the demand for parking rises or falls. Engineer Adrian Muscat has been involved in designing a shared door-to-door taxi system for anyone with a smart device. The system responds to a caller within 30 seconds with information on journey time and cost, and payment is made electronically once the trip is accepted.
Engineer and director of the University of Malta’s Institute of Aerospace Technologies, David Zammit Mangion, spoke of developments in the field, including research and innovation programmes to develop less noisy and more fuel efficient aircraft and cleaner flights. Helping air traffic controllers and pilots to fly optimally can reduce emissions. Clean Sky is a joint programme between the European Commission and the industry. Clean Flight, funded by the Malta Council for Science and Technology, looks at optimising trajectories for cleaner flight operations in Maltese airspace.
Biofuels for transport are a positive thing for the environment. Claire Grima described how finding the right materials to withstand a challenging acidic environment proved an opportunity for Trelleborg, which produces seals for the automative industry.
The subject of energy efficiency at the University of Malta was treated by engineer Joseph Micallef and an evaluation of photovoltaic technologies was given by Mark Zammit.
Next year’s Chamber of Engineers conference will be on energy efficient buildings.