Originally Posted by BillKny
Everybody talks about "efficiency", but most of the time they are avoiding the REAL question (at least to me) what is the cheapest? I have no real interest in the amount of energy input or how much power is lost
, all I care about is the dollars expended.
The equation is really simple for most boats. Most boats will not be able to cook using just solar
power, they need to run a generator. If you are running a generator, there is NO WAY your cooking will be cheaper than propane--if you are honest with the costs. Fuel, maintenance
, and depreciation for generator and batteries
will be significantly more expensive than propane
Most modern boats have some solar
and also have a generator, or a high-output alternator
on the propulsion engine
. With a well designed system, most of the power can come from solar.
My analysis gives me $0.80 to $1.00 per kwh from a generator. Most of this is fuel and scheduled maintenance with capital costs and repairs
being about a quarter of it. The cost per kwh works out about the same for (boat-sized) diesel
generators as it does for suitcase gasoline generators, which use more fuel.
In reality on a boat
solar power that goes through a LiFePO4
bank and an inverter
is going to cost about the same given the high capital costs and the fact that even serious cruisers aren't on the boat
every day of the 10 year life of the system.
Propane systems cost money
to install and maintain too, and as Adelie points out the logistics of purchasing
propane are difficult, sometimes particularly so depending on your situation, and the worldwide trend towards bottle exchange is making this worse.
If the dollars matter most then the break-even point is around $11 a gallon or around $24 for a 10# cylinder, assuming you start with a boat with a complete, working propane system. In most cases the fill itself is less than that, but not always, especially if you're stuck dealing with a bottle exchange vendor.