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Clean & Green - Creating an all electric garbage collecting boat

Towards a zero-emission garbage cleaning boat

We’ve written before about how important it is to clean up plastic pollution in the ocean as well as the war on plastic more generally, but of course these are just part of a much bigger effort to deal with the climate emergency.

We are extremely proud of the work that our pollution control vessels are doing around the world, but we have long been aware that the emissions from the engines on our boats, whilst minuscule in themselves, are contributing to the problem.

In this post, we look at the issues of zero-emission propulsion in the marine environment, and more specifically at the difficulties of using an electric drive on a garbage collecting boat given the need for range and durability.

Why are electric boats important?

Just as other forms of transport are being forced by regulation, fuel costs and public pressure to reduce their carbon emissions, the maritime industry have been looking for ways to operate more sustainably, and that naturally leads boat builders towards electric propulsion.

We have been determined to reduce the overall environmental impact of our garbage collecting boat, to make sure that we aren’t causing different types of pollution whilst we clean up plastic waste! Until the last couple of years though, our options for reducing carbon emissions during collection have been restricted by the limitations in electric propulsion systems available for boats.

Electric Boat facts

The first electric boat was developed in 1839 in St Petersburg, Russia, and carried 14 passengers at 3 miles per hour

The MS Tûranor PlanetSolar is the world’s largest solar powered boat, and was the first electric boat to circumnavigate the earth

The electric shipping market could be worth more than £15bn by 2027

Advantages of Electric Boats

Reduced or zero carbon emissions

Avoid potential pollution from fuel spills

Reduced maintenance requirements - no oil change, impeller change, diesel filter change etc.

No engine noise

Reduced vibration

Reduced fire hazard

History of electric boats

Historical highlights of the development of the Marine Vessel’s Power System from 1830 to 2015  Source: Skjong et al. 2016
The history of the electric boat is extremely interesting, with the first electric boat demonstrated in 1839, and numerous examples in use during the nineteenth century as battery technology improved the first batteries were massive, heavy and difficult to recharge (the first one weighed more than 180kg!) https://ethw.org/Electric_Boats. Despite these improvements (and this was a constant theme in the evolution of electric boats) the introduction of the internal combustion engine meant that the electric motor was largely eliminated from commercial usage by the 1920’s.

There were a couple of notable exceptions, including where boats were to be used in environmentally sensitive areas such as the Konigsee Lake in Germany, where non-electric boats were banned, and in the military where electric motors remained in use, particularly in submarines.

Interest in electric boats revived in the mid twentieth century, and The Electric Boat Association (https://www.electricboatassociation.org/) was formed in 1982 to promote the idea in the UK. As interest in the subject has grown a number of other publications have sprung up, including https://plugboats.com/, and this trend is rapidly picking up pace. “Increasing fuel costs and regulation of emissions are encouraging operators, shipbuilders and researchers to seek improvements in marine vessel efficiency”,

The critical development over the last few years in electric propulsion, for other uses as well as marine, has been rapid and continued improvement in battery technology – in particular improvements to cost, weight, durability, recharge times and capacity. This has meant that electric motors have become suitable for a whole range of marine uses where previously considerations of range, weight or cost made them impractical.

What Are Water Witch Doing?

We have been building boats for waterway maintenance for decades, and the sustainability of our designs have always been of the highest importance.  Using the weight saving advantages of aluminium construction we can run on a relatively small power range.

Our first electric drive version of the Versi-Cat debris collection craft, built back in 2011 to keep the canals in Amsterdam clean, required a lot of design modifications to accommodate the system.  The 8.0m x 2.5m boat ran on two 2 3.5kW pod motors.  Li-ion batteries were not readily available and were extremely expensive at the time, so to achieve 6 hours of continuous operation we required a bank of 16 x 330 Ah AGM batteries with a combined weight of over 400kg.

Thanks to the huge advancement in battery technology in recent years – in particular improvements to cost, weight, durability, advanced power management, recharge times and capacity has meant that electric propulsion is now a practical, cost effective option.

We can now offer electric drive options which easily provide the range and durability required for our vessels to function effectively.  Now waterway maintenance and debris retrieval can be entirely zero-emission.

Following extensive tests were delighted to announce in November 2019 that our whole range of Versi-Cat litter collection craft and pontoon workboats are now available with optional electric propulsion as standard.

“We have been impressed with the reliability and advanced technology of the latest Torqeedo e-mobility range. We are passionate about the environment, and we see this technology as a critical step towards being carbon-neutral in our efforts to keep plastic pollution from entering our oceans and landing on our beaches.
Jackie Caddick, Water Witch Director

The propulsion system for the 7.0m Versi-Cat craft consists of the Torqeedo Cruise 10 outboard motor, two Torqeedo Power 48 lithium-ion batteries, weighing in at only 74kgs each, and cockpit control panel that gives the operator an at-a-glance view of system status, including range at current speed.

The outboard configuration of this system allows Water Witch to offer it as a direct replacement to our standard four stroke engine power option, with a top speed of 7.5 knots and 6-8 hours continuous operation between charge. Performance increases in battery technology, with 70% lower volume and weight than comparable batteries, means that trim and stability is not affected and overall vessel weight is kept low for easy shipping and towing by road.

Although the Versi-Cat’s main function is retrieving plastic litter, debris and aquatic vegetation, the design also includes a range of ‘pods; that sit between the hulls.  It is extremely adaptable for a huge range of applications in addition to garbage collecting boat, ranging from fast response pollution control needs, to mobile pump out and general maintenance support. According to Jackie, the potential for this system is therefore huge, with the potential to make a real environmental improvements for operators, which include some of the most prestigious Marinas in the world.   She said that “this is a clean, green, safe, zero-emission solution with long life, low maintenance and minimal operating costs.

Here at Water Witch, we hope to play our part by providing fully electric debris collection and trash retrieval boats to Ports, Marinas and Waterways Authorities around the world. Our range of tried and tested workboats have been developed to offer users a versatile, multi-purpose craft that can perform a wide range of duties in addition to efficient aquatic trash and debris removal.

Water Witch partner with Marina and Harbour Authorities, Waterway Authorities and tourist resorts to provide peace of mind, deliver efficient management and maintenance of your marine environment that will improve your own green credentials and ensure your visitors keep coming back.

 

If you need more information about our workboats and innovative solutions for marine debris and waterway cleanup, please contact us.

 

+44 (0)151 207 4874 | info@waterwitch.com

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