FRIENDSHIP SYSTEMS Discusses Yearly CO2 Emission Reductions by CAESES

FRIENDSHIP SYSTEMS AG helps its customers decrease energy consumption and emissions by improving their ships, turbomachinery and engine components.

We have taken a look at the question of how many COemissions are saved from simulation-driven design with CAESES® every year.

Top-down approach

A total of 90% of transport is made at sea. Commodities and goods are shipped in the very sense of the word. To do so, there are currently more than 50,000 merchant vessels in service.

In 2017, the fleet comprised around 17,000 ships for general cargo, around 11,000 bulk carriers, more than 7,000 crude oil tankers, more than 5,000 container ships, and almost 4,500 RoPAX ferry and passenger ships according to Statista. Other larger ships such as search-and-rescue vessels, dredgers and salvage ships, offshore supply vessels, windfarm installation and support vessels, fishing vessels, tugs, pilot and workboats, naval ships and yachts also sum up to about 50,000 entities. Therefore, about 100,000 ships are in service today worldwide.

The COemissions from shipping amount to 3%-4% of global COemissions, which sum up to a total of 32 billion tonnes of man-made CO2 every year. Therefore, around one billion tonnes of COcan be attributed to ships. These numbers differ slightly depending on the source.

Many of the world’s biggest shipyards, most notably Hyundai, Samsung, and DSME utilise CAESES® for the simulation-driven design of their ships. And so do many of the well-known model basins, consultants and ship design offices.

Many of our users report that they improve their hull forms with regard to resistance and propulsion by around 5%. The savings are sometimes higher and sometimes they are a bit lower (around 3%) when setting out from a good starting point.

Since CAESES® was first released in 2007 and since FRIENDSHIP SYSTEMS started to promote the simulation-driven design of ship hull forms in the early 2000s, more than 40,000 ships have come into service, partially replacing older vessels.

A tangible number of these ships have undergone optimisation for lower energy consumption directly by using CAESES® or indirectly by utilising simulation-driven design as researched and promoted by FRIENDSHIP SYSTEMS AG.

We estimate that around 10,000 ships need about 4% less energy by now than they would have needed in the past, with an additional 1,000 ships every year. In 2019, this is approximately 10% of the fleet.

Naturally, ships are not always at sea and they are not continually benefiting fully from the energy savings achieved at the design stage. Therefore, we assumed an average of 220 days at sea per year and a utilisation rate of 75% of the possible savings when sailing.

Bringing all this together, we estimate the COreductions to amount to 2,835,288t in 2019. Keeping the many assumptions and rougher numbers in mind, we felt that we should introduce a very conservative safety factor of two into the analysis. Rounding off to a smooth number, we then get an annual reduction of 1,400,000t of CO2, i.e. much more than one million tonnes.

FRIENDSHIP SYSTEMS AG CEO and co-founder Dr Stefan Harries said: “Our CAESES® users manage to reduce CO2 emissions by much more than 1 million tonnes annually. This is why we do what we do and this makes me extremely proud of our team and company.”

How does this relate to emissions from other sources? A standard semi-detached family home in Germany would burn about 1.5t of oil for heating per year, emitting some 3.9t of CO2. That means that the above savings equal the private emissions of around 350,000 houses, an equivalent to providing cosy homes for the population of a large German city such as Munich.

Bottom-up approach

Let us take a look at a representative ship for estimating CO2 emissions in a bottom-up approach. A container ship with a capacity of 4,100 containers (TEU) would have an engine of 37,000kW and would typically be at sea for about 6,000 hours per year. Fuel consumption is approximately 0.166 kg/kWh. Assuming a utilisation rate of 75% and an improvement of 4%, approximately 1,100t of fuel are saved annually. These savings correspond to just about 3,000t of COemissions annually for one single ship.

As a second example, let us analyse a slower steaming Aframax tanker with an engine of 13,500kW. With similar assumptions as the container ship, the yearly savings then amount to about 400t of fuel and more than 1,000t of CO2. Consequently, the lower estimate of 1,400,000t of CO2 emissions derived from the top-down approach for 10,000 ships seems very conservative indeed.

Apart from the ecological impact, there naturally is an economic component too. Increasing energy efficiency readily reduces operational costs in shipping. World bunker prices for IFO 380 are around €430 per tonne (February 2019).

Annual costs are therefore reduced by €473,000 for the container ship and by €172,000 for the Aframax tanker. Since most ships are in operation for 20 years, this is adding up to a pretty large sum.


We believe it may not be so important which of the numbers, those derived from the top-down or the bottom-up approach, are more accurate or more reliable. The important message is that each tonne of CO2 that is not emitted helps to reduce mankind’s environmental footprint. We are more than happy to be part of the effort of making our world greener.



More About This Company