Electric vs. combustion - are electric boat engines worthwhile?

Electric vs. combustion - are electric boat engines worthwhile?

What are the advantages and disadvantages of e-motors and internal combustion engines for you?

We give you a brief overview of the similarities and differences of electric boat engines compared to internal combustion engines. What are the advantages of the electric motor on the boat? Where are the [supposed] disadvantages? We hope you enjoy watching the video or reading the article! Feel free to write us your questions and suggestions.

ELECTRIC vs. BURNERS on the water | Advantages and disadvantages at a glance

Due to the current cookie settings, the Youtube video cannot be displayed.

Similarities between electric and combustion engines

Can I go just as fast with an electric motor as with my combustion engine or am I slower on the road?

Don't worry!An electric motor provides just as excellent a thrust for your boat. So when it comes to maximum speed, the two types of motors are on par.

What does the speed of the boat depend on?

We thought at the beginning that only the engine is decisive for the speed. However, the speed is more dependent on your boat than the motor. In our article {%ckve71par01nf3p66lenx45la___Electric boats - everything you need to know%} we explain more about the economic speed and what values are necessary to calculate the speed.


Energy consumption of the electric motor and combustion engine on the boat?

This relationship is also constant! ! Important: The faster you drive, the more energy you use. No matter whether with electricity, petrol or diesel. And that exponentially in the third power! What does that mean? If you want to double the speed, you need eight (!) Times as much energy as before.

We, therefore, recommend traveling at a gentler speed regardless of the engine. Of course, you can crank it up! However, you should always have enough battery capacity or additional fuel onboard so that you don't stay dry!

So the decisive factor is not the energy consumption, but rather the type of storage onboard and there are differences here. You can read more about the differences in the range below in the article.

Energy consumption of the electric motor and combustion engine on the boat?

How the electric motor and combustion engine work

Technically, the electric motor and combustion engine is of course fundamentally different. You can read more about this in our article on how boat engines work. Rather, it is about the purpose that both engines pursue.

The propeller converts the engine's power into thrust and pushes the boat in the desired direction. Combustion and electric motors have a common purpose and ensure maximum driving pleasure on the boat trip. The design and how the drive shaft is rotated works differently.

Installation of the boat engines

The installation of the engine on your boat looks the same in any case. An electric outboard is mounted just like a petrol outboard. The same applies, of course, to the other engine types, regardless of whether flange engine, inboard or sail drive. If you have specific questions about installation, take a look at our article on the various electric motors.

Differences between electric and combustion engines

Is an electric boat motor worthwhile for my boat?

What are the advantages and disadvantages now? The most important question for boat owners: What is better for me and my boat? To make the comparison easier for you, we will show you the advantages and disadvantages from the perspective of the electric motor.

The advantages of an electric motor in boats

The advantages of the electric motor compared to vehicles with an internal combustion engine are many. In our view, the electric motor has many advantages, but it is not always 100% suitable. There are also some challenges that electric motors pose. We will show you how you can easily eliminate these supposed disadvantages with our help.

1. The volume of an electric motor

An electric motor is significantly quieter than an internal combustion engine! The volume of the engine varies depending on the type and structure. Electric motors without gears have a volume of only 30-60 decibels and are practically silent. Electric boat motors with gears, on the other hand, are somewhat louder, around 70 dB.

In any case, electric drives are significantly quieter. The noise of an internal combustion engine is reminiscent of the main streets in a big city. For us, that was exactly the reason to think about an electric motor for our boat. When we go on a boat trip, we mainly think of nature and relaxation.

Our opinion: There is no alternative to electric motors when it comes to volume ... apart from muscle strength, of course, here you are even doing something good for your health!

  • Electric motors are significantly quieter or completely silent
  • Emission-free, no unpleasant smell
  • Running costs significantly cheaper!
  • Environmentally friendly and ecologically sustainable
  • Future-proof: No fear of driving bans on the water
  • Maintenance-free: less effort
  • Greater safety on board
  • Efficiency and acceleration are higher
  • Handling and operation are easier
  • High flexibility: electricity onboard and in port

2. exhaust-free and a clean affair

An electric motor does not produce polluting and smelly exhaust gases when driving. Studies have shown that due to the lack of filter systems, 38 times more nitrogen oxides are released into the atmosphere. In addition, the engine does not need oil, which could leak.

You go to the lake with the family and have the smell of a gas station in the nose? For us personally, that was one of the most important reasons to get involved with the topic of electromobility. (Of course, there are exceptions who like the smell of a gas station). Nevertheless, we think of you and your health.

For animals and the environment, too, a lack of exhaust fumes or lubricants in the water has a major impact. In port facilities, we too often see a shimmering film of oil on the water. In addition to the animals, it also has benefits for the water quality in your area. Especially with the increasingly hot summers, the water quality of lakes and rivers in Germany is an important factor, which is favored by electric boat drives.

2. exhaust-free and a clean affair

3. No maintenance costs and cheap operation!

An electric motor is considerably cheaper in the long term. You are spared maintenance costs and you only need electricity as an energy source. Depending on the motor, especially in the low power range, electric motors can be cheaper from the outset than combustion engines.

The larger the battery, the higher the cost of the complete system. When purchasing, we recommend paying close attention to how much capacity you need on average.

We have developed a small cost calculator for you on our website. You can conveniently compare the annual costs from home and see when an electric motor is worthwhile for your boat.

You just have to state how often you drive each year and how much your boat uses. Another interesting point: you can see how much CO2 the boat engine emits over time and how much CO2 can be saved.

Break-even: When is an e-motor cheaper?

The payback period depends on the engine and your driving behavior. In the calculation, you compare the costs of purchase with those of operation: You buy a 15hp internal combustion engine for 4000€ and spend annually 800€ for gasoline and 200€ for maintenance. Or you buy a 11kw (15 HP) E-motor with battery system for 8000€ and spend only 200€ for electricity per year.

Your electric drive is already profitable after 5 years. After 10 years you have already saved 4000€. Fossil fuels are a limited resource. Do you think the price will rise in the future? We assume in the long term that gasoline prices per liter will increase significantly due to a CO2 tax or similar.

On the other hand, inexpensive solar cells offer the opportunity to generate electricity at zero cost. This electricity can be stored directly in your battery system.

Break-even: When is an e-motor cheaper?

4. environmentally friendly and ecologically sustainable

If you use green electricity for your e-motor, operation is even climate-neutral. What does climate neutral mean? No harmful CO2 emissions or nitrogen oxides are produced that pollute the air and endanger your health. In addition, pollutants such as fuel, oil or other lubricants do not get into the water. With electric motors, there is no danger of endangering the local waters and animals.

To generate electricity on the water itself, there is the possibility of mounting solar panels or small wind turbines on the boat. Alternatively, you can also build plants on the dock or on your boathouse and are also safe from rising electricity prices.

This is particularly suitable for houseboats with a larger roof area, but also already for smaller boats. Many solar modules are collapsible or can be rolled up and are thus easily installed on the roof or railing of the boat.

4. environmentally friendly and ecologically sustainable

5. No driving bans for electric boats

There is a lot of news in the news about car exhaust and thought about driving bans. This topic is also becoming more popular on the water - from 2025 onwards, boats with internal combustion engines will no longer be permitted in Amsterdam. Filter systems for cleaning the emissions are missing from boat engines. Boat engines generate 38 times more dangerous nitrogen oxides than cars.

Of course, there are already a large number of lakes with driving bans in Germany and Austria. We personally are sure that driving bans and higher circulation will increase significantly in the future. With an electric motor, you are on the safe side here. Especially when you are thinking about buying a new boat engine, you should keep an eye on this, not an insignificant factor.

6. maintenance-free - never stress again!

Mid-season you need to have wear parts changed from their engine. Not with an electric motor. Most E-motors are maintenance-free and have an extremely long service life with high-quality workmanship. This saves you a lot of stress. Does the motor still have a warranty? Where can I have the motor repaired and how expensive will it be? Perhaps you are technically more experienced and the replacement of a few wear parts will not cause you any problems. Then this is not so dramatic for you. We would be honestly completely overwhelmed with it! Therefore, we prefer to play it safe with an electric motor.

6. maintenance-free - never stress again!

7. higher safety on board

Safety is the be-all and end-all. On the road, e-cars impress with their higher safety. On the water, care must be taken to ensure dry storage for the battery, although splash water is not a problem. Most motors are absolutely splash-proof. Some batteries are even fully buoyant.The risk of fire is low, a special fire extinguisher on board we still recommend for certain batteries for safety. We mainly work with lithium iron phosphate batteries. These are non-flammable and therefore absolutely safe.

There is no need to handle highly flammable and explosive gasoline on board. From our point of view, it is much more pleasant without a gas can on board.

7. higher safety on board

8. Better efficiency and higher acceleration

An electric motor has significantly higher efficiencies: The energy conversion is very efficient because no-idling speed is required. This means that there is already a very high torque from the first revolution, which is why electric motors can also achieve a significantly higher acceleration.

In practice, this certainly sounds understandable: the faster it starts, the better for you. The same can be seen with electric cars. It's not for nothing that a Tesla Model S has such high acceleration and leaves all other cars behind at the traffic lights. And that despite the additional weight of the batteries!

9. Simple operation and good handling

Operation and handling are easier than with an internal combustion engine. Gasoline engines are usually started with choke, you have to "start" the engine, so to speak. And that often doesn't work the first time. With an electric motor, you start the engine directly at the push of a button.

Many engines have a speed control for stepless control. The advantage is that the motor can switch between driving forwards and backward without switching. Operation is much more intuitive, user-friendly and the speed can be regulated better.

Another advantage of electric motors is that the motor and battery can be monitored very easily. Manufacturers often offer special functions that are not directly integrated into internal combustion engines.

This includes calculating the remaining range, power consumption, GPS, or on autopilot. Of course, you could also add these features to internal combustion engines if you wish. They are often already integrated into electric motors and you do not have to invest more money than necessary.

10. high flexibility: power always and everywhere

If you use an electric motor, you always have electricity on board is. Other power consumers such as heaters, lamps, coolers and others can be operated on the same circuit.

Attention here early in the design of your batteries to the required capacity. When planning the route of your boat trip, you should also consider charging points due to the maximum capacity.

The good thing about electric motors: electricity is available almost everywhere! So you can recharge the battery both at your own jetty and in harbors, piers or at electric charging stations and are therefore still very flexible.

10. high flexibility: power always and everywhere

The disadvantages of an electric motor

Are boats suitable for an electric drive?

Skepticism about electric motors is still high. We want to remove prejudices and show you the advantages. Internal combustion engines have worked well for decades. However, electric motors are technically much more efficient and the only real disadvantage at the moment is the energy supply. Electric motors require electricity and a rechargeable battery usually serves as the voltage source on the boat.
  • Energy density and range
  • Acquisition costs of electric boat engines
  • Environmental impact of battery production
  • The weight of boat batteries
  • Charging time for electric boat engines

1. energy density and range

Petrol has an energy density 100 times higher than lithium-ion batteries. E-motors are 10 times more efficient. Effectively, the energy density is therefore 10 times worse and therefore has a negative impact on the maximum range.Therefore, battery weight and acquisition costs are an important aspect, especially for larger engines or continuous glide. It is therefore worthwhile to determine the battery capacity to the desired travel time and capacity optimally.

Indem you plan their routes or trips well, this disadvantage can be very easily circumvented. Electricity is usually available at any dock or port. If you use your boat during the day, it can be connected to the power grid overnight at the dock and will be fully operational again the next day at the latest.

While it is a disadvantage, because you either need more space in your boat for batteries or have a shorter range. Fortunately, an electric motor takes up much less space than a main engine with an internal combustion engine. From our experience, most conversions to an e-motor have not had any range issues.

1. energy density and range

2. Acquisition costs of electric boat engines

The acquisition costs for the battery increase with the required capacity. They make up a large part of the total cost of an electric drive system. An electric motor is definitely worthwhile for small and medium-sized motors. The costs are not much higher or even lower compared to the combustion engine.

In the past decades, there have been huge leaps in the energy density of batteries, at 5 to 8 percent per year. Many billions of euros are invested annually to drive development forward. The main players are, above all, the large automobile manufacturers, most of whom are planning to switch to clean energies by 2030.

Boat owners in particular benefit from this and the concept of electric motor and battery becomes more attractive. Battery prices are currently falling from € 1,000 per kilowatt-hour to only € 500. This development will be cheaper in the next few years and significantly more profitable for you! In addition to new types of batteries, a lot of research is being done on the use of hydrogen as an energy source. Hydrogen promises a similar range and quick refueling as with normal fuel.

However, the cost of the fuel cell is currently not yet competitive. We remain excited and will be at the forefront! And more importantly, we keep you up to date in our newsletter!

3. environmental impact of the production of batteries

Electric motors and battery systems have to be manufactured and transported to Germany. Resources are also used in the production process and CO2 emissions are produced. Also, the motors will mostly be produced in Asia and then imported.

We pay much attention to this fact and prefer manufacturers with a better CO2 balance. We have designed a special CO2 calculator on our website, with which you can calculate the CO2 balance in detail and see from when an E-motor is better for the environment.

In the media, just because of the E-cars much is reported about the production of batteries and the resulting damage to the environment. Here follows shortly a detailed article about the production and the associated emissions.

Pro kWh battery accumulates about 125 kg of CO2. This corresponds to the emission of about 60 liters of gasoline. Depending on the size of the battery, you can thus calculate very quickly after which consumption the conversion to a battery-electric vehicle is worthwhile. Mostly already within the first year!

3. environmental impact of the production of batteries

4. The weight of boat batteries

Larger lead battery systems are very heavy or very expensive for lithium. The purchase of lithium batteries only really makes sense for frequent drivers. You are a frequent driver from around 40 trips a year when the battery is completely discharged. However, as an occasional driver with AGM and gel batteries, you also enjoy all the advantages of an electric motor that cannot be weighed out with money alone.

As a rule of thumb, AGM batteries are about three times heavier. Usually, the tank flies out of the boat during a retrofit and provides enough space and a certain frame for additional weight on the boat. It is important to design the battery as optimally as possible, then a little more weight in the boat is almost no more disadvantage. Especially with sailing boats, they sometimes need a little more weight in the keel.

5. loading time for boats

The charging time until fully charged varies depending on the battery and charger. A boat can be refueled much faster with gasoline, diesel or hydrogen. On paper, this is another disadvantage of an electric boat drive. However, boaters are very rarely on the road for long periods of time without stopping.The charging speed of battery systems continues to increase and the flexibility of e-mobility continues to evolve. Tesla's Supercharger leads the way, charging a car battery up to 80% in 30 minutes. The number of charging stations on the water also continues to rise, so in the future even longer trips will be possible without problems.

Depending on your needs, we will be happy to jointly find a suitable charging option for your boat or an E-drive with the appropriate range. However, an electric motor is not really useful for every range and every area of application.

5. loading time for boats

Conclusion: comparison of electric and combustion engines

Both variants have their advantages. If you want to drive your boat silently across the lake, want to protect the environment and your local waters or love progress, an electric motor is just the perfect thing for you! With small and medium-sized motors, in particular, almost everything speaks for electromobility.

If you own a boat that needs a large engine for gliding, then you may be better served with a classic combustion engine. Mainly because of the battery system.

The arguments for combustion engines are, above all, the sometimes lower acquisition costs for larger drive systems and the longer range and travel time for large engines. In this area, electric motors are in the absolute premium segment, because everything is possible. Battery systems for sliding boats are particularly expensive. Nevertheless, electric motors are also ideal for gliding and have just as much power! Especially for lakes where only e-boats are allowed, there is no alternative.

The advantages of an electric motor are that it is quiet, emission-free, clean and mostly maintenance-free. Besides, the operating costs are significantly lower, which can be an economic advantage for frequent drivers. Electric motors have also been very popular with anglers, small boats, and inflatable boats for many years.

The price with a battery is often even lower or at least as high as for a combustion engine. The countless other advantages of the electric motor outweigh here. We are excited to see how the topic of e-mobility develops in Germany and Europe and look forward to your feedback and your experience with e-motors!

Your advantages using greenboatsolutions


Few clicks will save you a lot of time and stress!


You will get a result within 5 minutes.


You compare nearly 600 different electric motors.


You have an overview of more than 30 manufacturers.

contact image