T-Pain Is On A Boat: Re: [Electric Boats] Multiple charging sources charging 48v bank?

Monday, December 22, 2014

Re: [Electric Boats] Multiple charging sources charging 48v bank?

You ask the age old question. How can I get renewable energy without spending
a lot?

I start with wind. If your boat is at the dock, mooring, anchor, or whatever.
The last thing you want is enough wind to charge anything. The only thing I
ever used my wind generator for was an anchor watch alarm. "REALLY!" The
research says that 15mph might give you enough power with a small generator to
warrant the cost. The disk size and how far above any obstructions and wind
speed is what is used to determine how much power you might expect. Forget the
claims from manufacturers, what can be produced by the generator and what you
will get come down to the same factors.

If you want to spend the time to make the ideal wind system however consider a
system using an old motorcycle generator, or the system used in an inverter
generator from Honda. I made one with these components and was pleased with
the output. Unless you want to make a thread about this, that is as far as I
will go. As for a controller I recommend making one from an Arduino
controller. Any other system offered that I know of will not produce as well.
You will need:

1)a buck boost circuit to establish a charge voltage from the variable voltage
you can expect from the generator.(to use a PWM output from the arduino will
require you to build your own)
2)A bicycle sprocket and chain to keep your monster to the wind.
3)A weather station that outputs at least a USB message.(this function can be
done with a wind paddle and direction sensor)
4)An understanding of airodynamics that allow you to change the RPM of the
generator based on windspeed.(if you experment you can study the output and
wind conditions and find the sweetspot for all conditions and program an
algorithm)

Best control is obtained when you turn the generator into the wind because
enough windspeed is present to produce useful power. Using the wind direction
and a servo setup using the arduino as the controller point the generator into
the wind. Once again using the arduino switch with mosfets the field of the
generator to start the rotor, Then start collecting the power. When the wind
speed drops below useful speed shut it down by turning it out of the wind.
That is the best I can do. I just gave to you the design notes for the next
stage of my controller for free. How is that for service?
Note that 15mph is rotor start speed for most small useful wind generators. If
you give the rotor a nudge by starting it many no power situations will
produce some power, just questionable how much more power you will get.

As for controllers there are many for solar panels. I used Aliexpress to
import one for my 24volt 1200 watt panel array. MPPT is the only way to go and
even if the claim is MPPT if it is PWM you will not get all your panel has to
offer. For the record and no I will not give you my source, I put together my
24 volt system including a 3000w inverter, MPPT controller, 4@280watt panels
for right at 1200 dollars US. I spent the time looking for suppliers, groomed
them, and purchased when the timing was right. That is how you do the job at a
price.

Hope this helps
Kevin Pemberton

On Monday, December 15, 2014 09:19:53 AM you wrote:
> Next year I will be adding a full length hard canopy over my boat, and
> installing solar panels as I can afford them. I will also be building a
> wind generator, possibly using a truck alternator and feeding the regulator
> from a voltage divider, possibly using a motor, possibly building a
> permanent magnet alternator from scratch. I will be installing a small
> water heater, which could be used as a dummy load if required. I will also
> still have shore power charging as a backup when shore power is available.
> Eventually I will add a reserve bank, but I will not need to charge them at
> the same time. I will be okay with charging one bank, then the other. Some
> of my 12v loads I will convert to 48v and the rest will be fed from a DC-DC
> converter. There will be a separate isolated 12v battery fed from a
> dedicated solar panel for emergency power for vhf and navigation lights and
> this will not be connected in any way to the 48v system.
>
> So, I need to engineer a control system to use these multiple sources to
> charge a single 48v bank, and not be directly involved with charging any
> 12v stuff. My budget is as little as I can get away with. Initially I will
> only have about 500w to play with but I need to be able to expand to about
> 2kw as I add more solar. My main bank is 220ah or so, 8 6v GC2 flooded lead
> acid golf cart batteries. The reserve bank, to be added later, will be
> similar or smaller.
>
> My ultimate goal is to be able to run my propulsion motor during times of
> decent sunshine at 8 amps or so, and run normal house and nav lighting, and
> maybe at anchor or docked run a small air conditioner and fridge and crock
> pot, with only minimal assistance from infernal combustion generator or
> shore power. Cost definitely IS an issue. However, saving on the electric
> bill is not the reason for going solar/wind.. I want a fairly high degree
> of self sufficiency in the event of another hurricane like Katrina.
>
> So the main question is what sort of controller or controllers I need, and
> how many panels in series I should have. I am not looking for state of the
> art, high cost and highest possible efficiency. Just an acceptably
> efficient system that will tend itself to some degree and at least allow me
> to cook after a fashion, charge electronic devices, and allow some limited
> use of the propulsion motor as needed. Any knowledgeable advice or ideas
> appreciated, before I start buying stuff.