12 volt solar/wind for houseboat

We have been advised that gas refrigerators will soon no longer be acceptable on houseboats. I would appreciate information/advice as to options that are practical. The boat has two 120amp hour deep cycle batteries which are charged from the inboard motor (55 amp alternator) All of the lights water pumps etc are 12 volt electric----and these function well even if we do not run the engine for 4 or 5 days. However we would like to know what size of panels/wind generator we would need if we change to a 12 volt refrigerator (240 litre or similar) We have a standby 4.5 KVA generator---which we can use if necessary----but due to noise/vibration etc we try to avoid using this. We presently have a 1 amp solar panel which operates as a trickle charger for the deep cycle batteries. The engine has a separate 12 volt automotive type battery which is isolated from the houseboat electrics. Any advice/information would be appreciated.

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janvg downunder

I have an Engel MT45FP fridge of 40L capacity that peaks at 2.5A but usually draws a max of 1.5A and that's intermittent. Two 120AH batts should run that for days without need for recharge.

Not that I've yet run in camping mode, but I expected my typical ~40AH battery to handle that fine with daily solar recharges. And I was dimensioning for no greater then 20% discharge - the typical max for non-deep cycle batts. For deep cycles I'd go no lower than 50% (the typ recommended max) but limiting them to 20% discharge probably increases their life about threefold.

It's usually a case of deciding what discharge limit you want and then monitoring voltage until that limit is reached and recharging appropriately.