Now that our engine compartment is empty we have been able to more accurately work out where everything will go.
We can fit the motor batteries (each 300AH) at the side of the motor. By stacking two batteries each side we can have the entire motor and it’s “fuel” in about 600mm length from the end of the existing propeller shaft. Plus we could add a 3rd layer of batteries if we needed to double the motor battery capacity (while that would be higher than fully desirable the tops would be about level with the top of the existing fuel tanks so not much impact on stability). .
Forward of the motor and batteries we can fit up to 7 x 120AH house batteries within the existing engine compartment (we are starting with 4). These will be nice and low in the boat (considerably lower centre of gravity than the existing engine and tanks). Our busbars will also be mounted here.
Above the house batteries there is plenty of space for our two Victron inverters. Aft of the motor, where the fuel filters are we will be able to fit all our Solar MPPT controllers so they have short cable runs to the batteries.
All this means that we won’t need to use the original wet locker for the inverters and MPPT controllers, so we get that back.
When the fuel tanks are removed we will gain a huge amount of space in the cockpit locker (which used to lose space to 4 batteries, fuel tank, hot water tank, water pump, fridge compressor). We will also gain in the corridor to the aft cabin which we will be able to make a bit wider and have a huge storage area with shelves for boxes of clothes (maybe one day a redesign of this and the chart table will create space for our bikes).
So not only did the diesel engine fill this large space (and leak fumes out all into spaces in every direction), it also took lots of extra space for fuel, starter battery etc.
The electric motor doesn’t just bring all it’s systems into the one space it also allows a whole load of other things to fit into the same space, thus creating yet more space elsewhere.
In all this we will be able to see and reach every battery’s cable connection and LCD battery monitoring display. We will be able to remove every battery (although we will have to remove several to get to the furthest ones). We will be able to see and reach the last two remaining seacocks (for cockpit drains). We will have access to the propeller shaft and whatever shaft seal we end up with. We will also have better access to the deepest part of the bilge for the manual and electric bilge pumps that we plan to fit.
For a boat that we intend to live on when we retire all this extra space and accessibility are two reasons that alone would make going for an electric motor a great improvement. But we still have all the other benefits too.
Sustainable Sailing 