In shipping, speed is one of the biggest drivers of fuel consumption, and therefore emissions. That’s why at Lune we’ve designed our voyage-based fuel modelling to factor in the vessel’s actual speed, giving the most accurate shipment-level emissions data available today.

In this blog, we’ll explore

• Why fuel consumption increases exponentially with speed
• What the impact is on emissions
• How Lune uses speed to model voyage fuel consumption

The relationship with vessel speed and fuel consumption

The relationship between fuel burn and speed isn’t linear. Fuel burn doesn’t increase equally as a vessel gets faster. It shoots up exponentially. 

This is because as a ship increases its speed, the degree of drag and water resistance its hull experiences increases more and more rapidly. Imagine trying to run faster through water, the harder you push, the more resistance fights back. Ships experience the same thing.

That’s why even a slight change in speed has an outsized effect. Increase speed by a few knots, and fuel consumption jumps. Reduce it a little, and you unlock major savings.

What is slow steaming?

During the 2008 financial crisis, carriers adopted “slow steaming” to deliberately reduce speed to save fuel.

Cutting speed by just 10% reduced fuel consumption by nearly 20%. During a financial crisis it cuts costs; during a climate crisis it cuts carbon. 

Of course, running at very low loads does require careful engine management. However, with the right planning, slow steaming remains one of the most effective tools we have to cut maritime emissions.

Why speed shapes emissions

Fuel use comes from the total burned by a vessel’s engines: the main engine that drives the ship forward, and the auxiliary engines that power everything onboard. 

Deep dive: How to model voyage fuel consumption

The faster the ship goes, the harder the main engine has to work, and the more fuel it burns. That exponential curve means emissions can spiral fast when speeds climb.

How Lune uses speed to model voyage fuel consumption

Shippers are demanding accurate emission estimates for voluntary reporting, compliance, and to inform effective emissions reductions. If you want accuracy, you must account for speed. That’s where Lune’s emissions intelligence comes in. 

Many calculators rely on “standard cruising speeds” to calculate shipment emissions. These static averages can be out of date. However, details get lost at sea in these assumptions. Ageing vessels burn less efficiently, storms force them to fight the waves, and favourable currents can help them save fuel.

At Lune, we go beyond averages. We use AIS (Automatic Identification System) data to capture vessel speeds. That means we can build a real cruising speed profile for every voyage, and model fuel consumption based on what actually happened at sea.

The result is shipment-level emissions data that’s precise, transparent, and ready for climate action.

Driving green shipping using emissions intelligence

Speed matters for the climate. By modelling the relationship between speed and fuel, Lune gives logistics providers the emissions intelligence their customers need to comply with regulations, meet stakeholder expectations, and lead the shift toward greener shipping.

To embed emissions intelligence into your logistics platform and see how voyage-based fuel modelling works in practice,request a demo.