By far the best bang for your buck with both houses & boats, is in energy conservation rather than production & storage
. The latter approach is 400% more $! On our self built 34' trimaran
, (12 years live aboard cruiser), We have all the comforts... Inverter
, dozens of lights & fans, windlass
, etc... We use fluorescent or LED lights
, vacuum panels
for super insulating the fridge, don't make ice, the smallest of everything, and minimize the inverter
use by running "black box" AC items like computers
& TVs directly off of 12V DC. (Using a transformer / converter to step up the boat's 12V DC, to the 19V DC that these "AC black box" items actually use.) This uses half the amps of using the inverter and plugging in theAC black box that came with the TV!
By going "green" as it were... We only use about 40 AH / day while living on the hook. (with fans running 24/7, making water
, and movies every night) We get this back exclusively from our 4 solar panels
(that = 280 W), and we are charged up by mid day, 340 or so days out of the year. Only when doing overnighters... we consume about 80 AH, and to fill the slight energy deficit, (the solar
usually gives us 50 to 60 AH/ day)... we run the engine
for an hour before sun up. Otherwise it's all free energy.
We started with Lead/acid Trojan L-16 batteries= (380 AH), and have downsized to L-14s =(340AH) This huge bank for our needs, is never more than 70 or at worst 80 AH down, so should last perhaps 10 years. (with hydro-caps) we only top off the water
4 times / year! You do have to remember to water however, at the first day of each season for example, otherwise.... that's how we ruined our first set.
Being a trimaran
, weight is important for us, so next time we may downsize yet again, to about 250 AH. This way we usually would be using 1/5th of our theoretical
capacity, and never more than 1/2. This conservation approach works best if done in conjunction with the original build, or a total refit
. Otherwise, the rule
is to size your battery
bank at a bit more than twice as large in AHs, than the max consumption
before charging. Wind
generation is loud, sometimes even antisocial, & very off & on. Diesel
is nasty, consumptive & requires that you "be there", Solar
is the champ. It will do the job if your W. of solar is sufficient. (Even factoring in very overcast days, my solar set up runs our boat 95% of the year) Put another way... We can rely on 50 AH/day from our 280 W of panels, 95% of the year. This was from Trinidad, to up the Rio Dulce, to the Chesapeake.
This does require an energy efficient boat however, OR a large one with a LOT of room for solar panels