Electric narrowboats
Oakums specifies electric propulsion around the boat, the batteries, charging sources and the way you expect to cruise. Electric prices start from £145,000.
The complete system
An electric narrowboat works best when propulsion, battery storage, charging and domestic energy use are designed together. Oakums develops the system around the boat, the waterways you intend to cruise and the time you expect to spend away from shoreline power.
The aim is quiet, responsive control with an installation that remains understandable, monitorable and serviceable throughout ownership.
Electric motor options
There is no single motor specification for every owner. Oakums offers a proven standard platform and can develop a more individually configured alternative where the brief calls for it.
Standard Oakums platform
A compact marine electric propulsion platform suited to responsive control and canal speed cruising. Motor output and the surrounding installation are confirmed against the selected boat and agreed use.
Individual configuration
A Torkmar system can be considered where the brief benefits from a more individually configured propulsion and energy package. Oakums matches the motor, battery capacity and charging strategy to the intended cruising pattern.
Final motor choice, output and equipment are confirmed in the written specification for each boat.
A standard, not a restriction
VETUS E-Line gives Oakums a dependable starting point, but a standard platform will not suit every route, boat or ambition. Where the evidence supports a different answer, Oakums will explore it rather than forcing the brief back into a conventional package.
That flexibility is disciplined by engineering. Every alternative still has to work as part of a safe, serviceable and properly documented boat.
Energy ecosystem
Each part affects the others. Oakums plans the installation as a whole rather than treating the motor as a standalone product.
Motor output and control selected for the boat, expected waterways and intended use.
Lithium capacity planned around propulsion and the energy used by everyday life aboard.
Shoreline, solar and generator support combined according to how and where you cruise.
Useful information arranged so you can see what remains, what is arriving and what is being used.
Electric, made simple
Efficient electric boating comes from making propulsion, storage, charging, domestic power and monitoring work together.
Solar, shoreline or generator
48V battery bank
Propulsion and life onboard
The easiest energy to replace is energy you never used.
Conversions and unnecessary loads take something from the battery.
Optimise for how a narrowboat actually cruises, not a headline power number.
Motor and propeller
A narrowboat is a heavy displacement hull. It does not climb onto the surface and plane like a speedboat, so the propulsion problem is different: move a large mass of water efficiently at relatively low boat speed.
01
Diameter, pitch, blade area, hull clearance and shaft speed determine how effectively the propeller can absorb motor power and accelerate water astern. A larger propeller can offer substantially more blade area, but only when the hull geometry gives it room to work.
Why 20in matters: a 20-inch diameter disc has 56.25% more area than a 16-inch disc. That does not mean 56.25% more thrust by itself, but it demonstrates how quickly the available swept area increases with diameter.
02
Torque is the motor's twisting force. For displacement propulsion, useful torque at low shaft speed allows a larger propeller to be driven without relying on very high RPM. This is why comparing electric motors by headline kW alone can be misleading.
Compare sustainable output. Peak or instantaneous torque is useful for manoeuvring and acceleration, but the rated duty and sustainable torque tell you much more about what a motor can actually maintain.
A worked example
Törkmar publishes these figures for its 48V Tidal 15kW. The point is not simply that it is a 15kW motor. It is engineered around high torque and relatively low shaft speed for displacement craft.
Propeller → water → thrust
How wide the propeller is. More diameter generally gives more disc area, subject to hull, skeg and counter clearance.
The theoretical distance the propeller would advance in one revolution through a solid medium. Pitch must suit motor torque, RPM and hull load.
The working surface transferring force to the water. Diameter alone does not describe the whole propeller.
Oakums principle: do not choose the motor in isolation. Establish the hull and propeller envelope, understand the cruising duty, then match motor, shaft speed, batteries and charging around the real boat.
AC versus DC
Your propulsion battery is a DC energy store. The motor and controller, together with many efficient onboard loads, can use DC. Familiar domestic equipment normally expects 230V AC. An inverter creates that AC supply, but every conversion and permanently energised device has an energy cost.
DC generation
Controls solar charging
Stores DC energy
The propulsion controller, DC lighting, USB charging and suitable DC equipment can take energy from the DC system without first creating a 230V household supply. That can reduce unnecessary conversion and standby losses.
This does not mean everything should be DC. It means each load should be considered as part of the energy budget.
For a kettle, induction hob, oven, hairdryer and other mains equipment, the inverter synthesises 230V AC from the battery. Modern quality inverters are efficient, but not lossless, and they also consume some power simply by being awake.
So the question is not merely how big is the battery? It is what is on, for how long, and how many conversions are happening?
Why inverter size matters
How quickly energy is being used. A 2kW appliance running for half an hour consumes roughly 1kWh before allowing for conversion losses.
How much has been used over time. Battery capacity and daily solar production make much more sense when discussed in kWh.
An inverter must cope with what may operate together. Hob, kettle and washing machine together create a different design case from each appliance used separately.
One boat. Two electrical worlds.
| Energy path | What happens | Design question |
|---|---|---|
| Solar → battery | DC is regulated by the solar charge controller and stored | How much roof area, shading and seasonal yield? |
| Shore or generator → charger → battery | AC is converted to controlled DC charging | Can the charger actually use the available shore or generator supply? |
| Battery → controller → motor | DC energy becomes controlled electrical drive and then mechanical shaft power | What does the boat really draw at cruise and under manoeuvring load? |
| Battery → inverter → 230V loads | DC is converted to AC | What loads overlap, and is leaving the inverter on worthwhile? |
Oakums approach: we design around the energy journey, not a collection of impressive component sizes. A larger inverter, charger, generator or battery is only useful when the rest of the system can make sensible use of it.
Three charging methods
A resilient electric boat should not be explained through one ideal summer day. The charging mix needs to work across your real cruising year.
Connect to a suitable mains supply while moored for dependable battery charging and onboard power.
Generate energy throughout daylight hours, with output varying by season, weather and shading.
Explore solar and off grid cruising →Specify generator support where winter, extended cruising or unusually high demand makes it appropriate.
Understand the numbers
Electric specifications become easier to compare when three different measurements are not treated as if they mean the same thing.
Describes the rate at which the motor can deliver power. A larger number is not automatically a better boat.
Describes the energy held by the battery bank. Usable capacity and genuine demand matter more than a headline alone.
Describes how quickly energy can be returned under suitable conditions. The source and battery limits both matter.
Oakums will show how the proposed figures relate to your expected cruising and domestic use before the specification is agreed.
Lithium battery systems
Battery capacity is selected after considering propulsion, cooking, refrigeration, laundry, entertainment and working aboard. Monitoring, system protection, isolation, ventilation and access for future servicing form part of the design.
Monitoring
Useful monitoring turns a complicated electrical system into information a skipper can act on. The display should answer real questions rather than simply present more numbers.
Energy remaining
Energy arriving
Propulsion demand
Motor and controller
What is active and contributing
A change in motor draw can itself be useful information, prompting a check of conditions or possible propeller fouling. Good data should reduce guesswork, not create more of it.
Choose with evidence
Oakums offers diesel and electric propulsion. The right answer depends on the experience, budget and independence you want from the boat.
Electric may suit you if
It can be a strong fit when your cruising pattern, charging opportunities and onboard demand support the proposed system.
Look carefully if
Long consecutive cruising days, shaded moorings and high winter use may increase reliance on generator or shoreline charging.
Diesel may suit you if
Oakums can specify diesel where it is the more practical and better value answer for your intended use.
Battery basics
You do not need to become an electrical engineer, but a few terms make an electric boat much easier to understand.
Battery chemistry comparison
| Characteristic | LiFePO4 | Lead carbon |
|---|---|---|
| Charge efficiency | 95–98% | 80–88% |
| Guide cycle life at 80% DoD | 4,000–6,000+ | 1,500–2,500 |
| Cold conditions | Needs temperature management | Generally more tolerant |
These are broad guide figures, not a promise for every product. Actual performance and service life depend on the selected equipment, temperature, charging, discharge pattern and system management.
Solar panels
Panel construction, installation, shading and how the boat is used all affect the result.
Low profile and practical on a cruising narrowboat. Substrate quality matters because a steel roof expands as it heats, so the installation needs to accommodate movement.
Often lower cost and capable of being aimed towards the sun, useful where a boat spends longer stationary.
Cell technology
| Cell technology | Guide efficiency |
|---|---|
| Monocrystalline | 19–22% |
| Monocrystalline PERC | 20–23% |
| Monocrystalline bifacial | 20–25% |
| Polycrystalline | 15–19% |
Solar figures are guides rather than guaranteed output. Roof area, panel specification, installation, season, temperature, weather and shading all affect real generation. Explore the complete Oakums solar approach →
Installation
Cable size, run length, terminations, fuse voltage rating and manufacturer torque settings all matter.
Conductor size must suit current, distance and allowable voltage drop.
Correct crimping, insulation and clean contact surfaces are critical to a reliable high-current system.
Fuses must suit both current and DC voltage. Terminals should be tightened to the equipment manufacturer's specified torque.
Current electric range
Start your Oakums
Tell us where, how often and how far you expect to cruise, plus the equipment you want aboard. Oakums will explain the practical system, current range price and next step.