A range of opportunities to save money and increase efficiency are abundant within the world fleet, with some requiring a low initial investment, and banks are listening to the case for retrofitting, delegates at Tuesday's global maritime environmental congress (gmec) were told.

"We find that ships are often not designed for the conditions in which they are operating," said Jan Otto de Kat, director of energy efficiency at ABS. "In a previous session [at gmec] it was mentioned that and there is a latent potential for the increasing of emissions within the fleet. On the other hand there is also a lot of potential to improve the efficiency in this particular area."

Offering a particular example from a section of the world container fleet, Jan-Henrik Hübner, global head of shipping advisory practice at DNV GL Maritime Advisory showed a spread of fuel consumption per thousand cargo miles that found a 30% difference between the least and most efficient panamax boxships. "That's a lot, especially when you consider that bunkers are the largest cost consideration for a vessel."

Despite the recent drop in newbuilding prices and the impact that has had on CAPEX costs for new vessels, Hübner demonstrated that even if CAPEX costs are removed for an older vessel, the optimised new vessel still represents a significant daily saving through increased efficiency and the considerably reduced bunker costs that comes with it.

Energy efficiency retrofits are not just the preserve of older vessels, Hübner stressed, "One of the first big retrofits we've seen here, especially in Hamburg, was a 13,000 teu vessel that was one year old. There is still significant potential for vessels that were designed a few years ago."

Juha Heikinheimo, president of software house NAPA offered a case for the low hanging fruit of energy efficiency, where weather routing, trim optimisation and optimised voyage planning can bring significant savings. "All are easy to implement for a ship," he stated. "I am surprised that the industry is not taking this potential seriously, that they would not take simple, readily available solutions that are not costly."

With its monitoring software, NAPA has also kept track of the efficiency improvements ships have benefitted from after retrofits, and can attribute savings to sepcific efficiency measures to show the return on investment as it happens, day by day.

Behind every vessel retrofit there needs to be a compelling financial case. Shipowners are all too aware that a more efficient ship not only reduces a company's environmental impact, but has the commercial benefits of savings through reduced fuel consumption and increased earnings potential through becoming more attractive to charterers.

For financiers, retrofitting can also bring multiple benefits. "We are a state-owned bank with a clear mission to support and finance climate protection investments and energy efficiency technology, so it is a clear part of our aim to support such kinds of investment," started Aida Welker, director maritime industries, KfW IPEX-Bank.

For the bank, it's all about the risks to its $90bn portfolio which finances over 700 vessels. "We see that energy efficiency has a deep impact on credit risk. Being an asset based bank, we have to take care of our assets which in the end might lead to a higher repayment potential through a better marketability of such assets. As a result, we see a better risk profile."

Using a tool supplied by DNV GL, KfW has been assessing the energy efficiency performance of new vessels it is financing, against IMO EEDI requirements, the rest of the KfW portfolio and the world fleet. The tool has also been used to assess its existing portfolio to help identify which retrofitting opportunities can be applied to ships, what that means in terms of fuel savings and where those improvements would leave the ship compared to its peers.