Saturday is the last day that ship operators can carry heavy fuel oil in the engine tanks of ships not fitted with scrubbers, without falling foul of international regulations.The rule is designed to help the sector, which includes cruise ships, cargo ships, and tankers, to reduce its impact on the environment.However, the shift is not as clean as it seems. Both it and the switch to lower sulphur fuel should be viewed only as a bridge towards truly cleaner maritime transport.That’s a sentiment of Jens Alers, who has in-depth knowledge of shipping matters. He is group director of Bernhard Schulte Shipmanagement (Bermuda), which has offices in Par-la-Ville Road.“What we are seeing now, what started on the first of January and what is happening now, is just a bridge to a new era; not just in shipping, but how all of us think about power production and utilities,” he said.At the beginning of the year stricter global fuel sulphur content regulations came into effect. An associated phase-in transition period ends on Saturday. The International Maritime Organisation regulations mean it is no longer acceptable for ships to continue burning heavy fuel oil that contains sulphur content above 0.5 per cent m/m [mass by mass] without taking measures to reduce the resulting sulphur oxide emissions.One of those measures is the installation of so-called scrubbers that extract sulphur fumes from ships burning heavy fuel oil. The scrubbers cost from about $2 million to $11 million to buy and install, however they are not all equal. Some are closed-loop systems, which do not discharge into the sea but store the extracted sulphur to be removed at safe disposal facilities on shore.However, the majority of the estimated 4,000 ships globally with scrubbers have open-loop systems, which emit washwater into the sea. This is warm, acidic, and contains carcinogens and heavy metals, according to the International Council on Clean Transport.“Dozens and dozens of countries no longer want you to use your scrubber if you’re using heavy fuel oil in their harbours. Scrubbers make certain waste which is kind of acidic. It’s not good to dump it anywhere,” Mr Alers said.As the IMO’s new standards arrived, many ships switched from burning heavy fuel to low-sulphur fuel. The low-sulphur fuel is more expensive, but the price spread between the two has narrowed, with the low-sulphur fuel costing $165 more per metric tonne last week, according to a market snapshot.Exhaust fume scrubbers and low sulphur fuel are no panacea, even as the shipping sector makes efforts to reduce its impact on the environment and curbs harmful emissions, including greenhouse gases.Mr Alers said: “Low sulphur fuel oils, because of the additives in it, produces a lot of black smoke. There are side-effects from having low sulphur fuel, because they need certain additives to keep the fuel stable, and the way these additives burn can be very unclean.”He sees liquefied natural gas as the best fuel option for ship propulsion and power plants during the next 25 to 40 years.Bernhard Schulte Shipmanagement looks after 600 ships and 20,000 employees. It manages tankers, container ships and VLCC, or very large container ships. Last year it took delivery of its first gas fuel supply vessel, which can carry 7,500 cubic metres of liquefied natural gas and will deliver cargoes to power companies in the Baltic, and to other ships that use LNG for propulsion fuel.LNG is not a perfect solution either, but it does eliminate the problem of airborne particulates created by burning fuel oil.“It still has only a quarter less CO2 [than traditional ship fuels], and that is a potent greenhouse gas,” Mr Alers said.“Then you have a so-called methane slip, because LNG predominately consists of methane. Methane is a more powerful greenhouse gas than CO2. Technology is being developed to take care of that.”Ultimately, he sees LNG as being a bridge fuel, on land and sea, to a hydrogen and renewable energy economy.He points to The Hydrogen Economy, a book by American economic and social theorist Jeremy Rifkin.“He basically laid out the idea of distributed energy production, where people have wind turbines, solar power, and then making hydrogen.“Hydrogen is very expensive, it needs a lot of energy input to make something that you then have to chill to -247 degrees Celsius to keep liquid. But if you can make it with what is practically free energy, like solar and wind, then it makes sense.”Mr Alers said that in places where there is a surplus of naturally accruing renewable energy sources, such as wind, sun, or waves, it becomes more practical. As an example of a place where ocean energy could potentially be harnessed, he mentioned the Orkney Islands, off the northern coast of Scotland, where powerful currents ceaselessly stream between the Atlantic Ocean and the North Sea. He said in places like that “these kind of future solutions are possible”.