Saving fuel with a DC-Hub

DC-Hub is the best solution for cost efficiency

Achieving cost efficiency can be challenging and can shed a lot of light on the quality of your operations. What kind of shipowner are you? Are you the type to simply go around switching off the air conditioning and laying off employees to keep costs in line? Or are you determined to lower costs through investments in the best technology?

If you’re in the latter group, and we hope you are, you can achieve substantial savings by improving energy efficiency. But why focus on fuel? Of all a ship’s operational expenses (OPEX), fuel accounts for almost 50% – more than even crew wages. As a result, ship operators face more and more pressure to improve energy efficiency.

Overall, we’re still a ways off from implementing the ideal energy sources. In the future, we expect approximately 80% of shipping vessels to be fully electric or powered by hybrid energy systems. Many will have multiple power sources and main engine gensets running on diesel, LNG or both. And as part of the global movement to reduce emissions, we expect greater developments in renewable power from hydrogen and, possibly, ammonia fuel cells, as well as solar and even wind.

Other potential power sources include batteries and shore and shaft generators. Managing stored electric power effectively is particularly important when vessels need to sail pollution free – in electric mode. Examples include superyachts sailing into protected bays, ferries in emission-free zones and cruise ships navigating urban ports.

However, we feel that these improvements in fuel efficiency will not be enough.

Traditionally, shipbuilders have designed ships using a single operating point as a reference for tuning energy efficiency levels. While ideal for ocean-going vessels, such as container ships, this method may not be suitable for vessels such as tugboats or offshore supply vessels (OSVs).

These ships have a dynamic operational profile that makes achieving energy-efficient operations more challenging. For example, they may spend only a fraction of their operating time leveraging full-power modes. While most of the time, say greater than 80%, they remain in a transit or standby mode with significantly lower power requirements.

In such situations, switching from an AC to a DC grid not only provides better fuel consumption and other cost savings but also helps improve reliability. And, with DC, the power from both genset units and energy storage is channeled through the DC distribution system to supply propulsion, service and hotel loads.

Such designs provide the flexibility to optimize the load allocation among multiple power sources, enabling reductions in fuel consumption and achieving lower or zero-emission operations. For example, you can implement strategic loading with an energy storage system to maintain an optimal engine operating range that improves fuel efficiency. You can also use batteries as an alternative auxiliary power source, reducing the need for auxiliary engines and allowing vessels to maintain their functions while reducing their GHG emission and other pollutants.

Overall, it’s important for the shipping industry to choose the most energy-efficient equipment to help lower global carbon emissions. Forward-looking shipowners are already doing this and, as a result, saving money in the long run. This is a win-win for everyone – especially the climate.

In this context, we believe that implementing the Yaskawa Environmental Energy / The Switch DC-Hub is the best solution. It can reduce fuel burn by up to 35% – depending on the ship’s operational profile and fuel hedging – while boosting energy efficiency, hence causing less emissions. The DC-Hub is also easy to integrate with energy storage devices, such as batteries and fuel cells, minimizing the number of conversions required.

For you and others in the shipping industry, we believe it’s time to switch to this smart solution to save on fuel and achieve cost efficiencies.

Carlo Cecchi