Good points Eric.
Those free sources are deceptive though, as the larger the electrical
drain from all equipment, then the less valued impact that solar etc
have on the whole scenario, as you end up with a boat that is ICE
powered, via an electric drive.
Or that requires plugging in to shore power daily.
With larger boats, the battery cost too, gets higher, if you are
considering range from batteries alone.
When I first joined this group, one response to my various questions
mentioned something like.... that most people convert to electric
despite it being generally more expensive than fitting a 'new' ICE.
The great thing is, though, if you minimise the batteries, yet err on
the 'sensible' choice for the electric motor, which would seem to be
around 5 kw for a 30 foot boat, that is, around hull speed, then the
initial setup expense can be lowered.
In going the deliberately underpowered route, such as is my own
thinking, even more savings can be made, because of not trying to
compete in all aspects with ICE. It also might place the solar as a
higher percentage source of power.
Another point in the whole scenario is that the average ICE has masses
of redundant horsepower, simply because there is little more cost to
selecting, say, a 2 litre engine over a 1600cc one. And even
professionals and 'engineers' will tend to err on the safe side to
prevent egg hitting their faces. The simple fact is that excess
generally goes unnoticed, whereas the opposite of excess creates issues.
From the group activity here, it seems that those involved
professionally with electric drives (even those who keep it secret!) are
more knowledgeable, and therefore less likely to just choose a larger
drive as a cover-up for their own lack of knowledge.
My own thinking is erring on change from wanting the ICE in addition to
electric, (as a means of gaining low cost range), to adding the ICE in
the form of a generator. - I might never get the outboard bracket
installed! (And the way the wife keeps diverting my efforts away from
the boat, I might die before I ever flick a switch to move a boat!)
I am also erring to go a bit higher on the kw rating of the motor, with
maybe 3/4 hull max speed as a target.
Regarding your last comment re making choices for our own boats alone,
this is valid in every way - the title of the thread is 'purposely
underpowered hybrid' and choosing underpowering in comparison to the
regular excesses of ICE choice might be a good thing.
I suspect that the important choice would be simple, as it is whether
you wish to compete with ICE, or just meet your needs as a stand-alone
deal.
John
2e. Re: Valiant 40 purposely under powered hybrid.
Posted by: "Eric" ewdysar@yahoo.com ewdysar
Date: Tue Aug 16, 2011 10:05 am ((PDT))
Hi Steve,
Of course it will. And I have had to pay attention to fuel levels in
every vehicle/vessel/aircraft that I have operated. I don't start across
long journeys without filling up or knowing where I can re-fuel. The
electric drives are kind of unique in that you can bring equipment that
can generate more "fuel" from "free" sources like wind and sunlight.
And by adding an ICE generator, you've got triple redundancy that would
make NASA proud.
That said, in 10 years of coastal and offshore sailing in my ketch while
it was still diesel, Only once did I burn more than 1 gallon of fuel
while away from her berth. And that extra burn was my choice, I just
wanted to get home a little earlier.
If you're saying that a conversion should be able to be driven under ICE
power alone, then why bother with electric at all? It's just extra
cost, weight and complexity.
Luckily, the people that have converted (including me) are learning that
electric auxiliary sailboats are different than they sound like before
you own one. Even my years of EV conversion backgound didn't translate
to the electric sailboat experience. Most of my fears and concerns
related to range and power limitations just haven't materialized.
Even with this support group, each of us has to make the choices for our
own boats alone. We each have to figure out what is important, who to
believe and how to convert our boat (or not). I hope that you're
getting the information that you're looking for, I know that others here
have.
Fair winds,
Eric
1964 Cheoy Lee Bermuda 30, Propulsion Marine 5.5kW drive, 8kWh Lithium
batteries
Marina del Rey, CA
--- In electricboats@yahoogroups.com, "Steve" <sstuller@...> wrote:
>
> You can compare your battery bank to a fuel tank. If you are consuming fuel at a certain rate you have to replace it at the same rate or ,sooner or later, the tank (or bank) will be empty. Thanks. Steve S.
--
http://www.fastmail.fm - A no graphics, no pop-ups email service
No comments:
Post a Comment