hi. although i didnt really want to discuss it too much (really just want to find out about getting a
new boat with no engine nor associated thruhulls), but brief description:
actual exact set /
electric motor up wil depend upon what boat (in particular shaft) and whether i can get it new w/o engine or late model used and re-power it.
batteries will be a bank of at least 6 (i would prefer 10-12 if i could bear the costs) 24 V
lithium manganese batteries (77 Ah) which although quite expensive are light and can be nearly 100% deep discharged without ill effects which is absolutely key in this application. they weigh ca 40 lbs each, so 6
battery bank is ca 240 lbs.
will recharge with
shore power at the
dock and likely with onboard Whispergen genset. 800 W output and also acts as furnace and
water heater. will wait until
propane powered version becomes available in north america (within a year, accoring to manufacturer). this is light (90kg), provides power/heat/hotwater and on its own could recharge the entire bank of 6 batteries from a near zero charge state in approximately 18 hours (not that i anticipate operating it like this, it is, after all a sailboat
auxilliary engine), or hopefully provide just enough juice for maneuvering. am waiting for
propane version as i need propane on board for
stove in any case and then can completely eliminate any need for any liquid
fuel. less likely will go with Voller Emerald
fuel cell when commercially available in north america, however this is (surprisingly) heavier and comparatively untested, while the Whsipergen is a mature technology. dont want weight and liquid
fuel of diesel or gas genset. likely will supplement with solar/wind, but this could never be a significant contribution.
if end up with shaft drive, will likely go with solidnav or small OSSA powerlite (146 lbs). if can get engine-less boat will likely go with Re-e-power e-pod (65 lbs).
using re-e-power quoted numbers for the 3000 model and at 48 V, can expect at most (77Ah at 48 V from two 24 V 77 Ah LiMn batteries)/(50 A at cruising speed) = 1.5 hours per pair of two batteries. ie 4.5 hours from 6 batteries or 9 hours from twelve batteries. during this time if whispergen is on, would recharge to an additional 1-2 hours of operation, so you could add 1 to 2 hours to these estimates (again, this is a maximum).
project appears expensive, but would be greatly mitigated by savings from not
buying an engine (if possible), not needing additional furnace or
watermaker, very limited servicing, plus (small savings) dont need other house or starter batteries. i expect electricity charges to be similar to
buying diesel.
at this point i would
never argue that it will be cheaper than the usual diesel auxilliary arrangement, even considering operating costs, but the convenience and coolness factor is primary. also possibly fewer holes in boat,
possible weight savings depending on
battery bank size (with 6 batteries total weight 240 lbs batteries + 200 lbs whispergen + 65 lbs
motor + 40 lbs additional propane = 505 lbs compared with ca. 300 lbs for 30 hp
yanmar + ca. 200 lbs for 100 L fuel + 150 lbs (house + starter batteries) + weight of tank and cooling/exhause = ca 700 lbs.
lack of smelly/possible flammable liquids on boat is intriguing.
anyway, still looking for that engine-less boat.