T-Pain Is On A Boat: Re: [Electric Boats] Re: 48v diesel telecommunications standby gen?

Friday, September 21, 2012

Re: [Electric Boats] Re: 48v diesel telecommunications standby gen?

- but isn't the efficiency of peltiers lousy?

- i'd heard the $/W was way worse than most anything else e.g. solar panels

- i appreciate the sun doesn't shine all the time but then again your generator shouldn't be running too much either, and the heat generated by us 'meat puppets' etc below decks takes more energy to harvest (fans etc) than a peltier set up would return?

On 18 September 2012 05:53, Kevin Pemberton <pembertonkevin@gmail.com> wrote:

It might be time to pipe in.

If I were to use a transportation alternator I would likely use a commercial truck alternator. They are built to be abused. Second thing is the diodes used in this type or automotive alternators will withstand over 100v. For this reason I would likely change the regulator to run at the 48v charge voltage.

If I were to consider using a 3ph alternator I would consider downloading a PDF from the national renewable resource labs called investigation of self excited induction generators or something like that. I would carry it a little further and parallel the windings of the induction motor to half, or more, the output voltage.

as the air cooled diesel goes. I bought a 4000w genset on Amazon a few years back. The injector pump was jammed because it was assembled wrong. I fixed it by assembling it the way it should have been. Because of the problem, I had to replace the pump withing a year. No one was there to return the generator to. Being one cylinder it is loud, vibrates a bunch, and has never burned clean. Heat must be removed from below deck when air cooling as well. The advantage of water cooling is recovery of heat in the form of hot water.

If you would like quiet. I might suggest Peltier junctions. TE inc. in Michigan has Engineering papers to help design the system. I have built a 12v system and it cost me 250 US 150 of that was the junctions used two years ago. Because cooling water is available and the system works in heat variations as well as moving that heat. A system on a boat would be a no brainer. The heat can come from more than one source. Solar is a good choice because a meter squared of collector area in clear skys is good for 1000w of heat. When at rest solar can top the batteries. When in motion any heat source will do including a stove top burner. The system could be referred to as a solid state heat engine.

The system requires that energy only travels in one direction so diodes are needed.

Have fun and happy sailing.

Kevin Pemberton

On 09/15/2012 11:42 AM, Robert Lemke wrote:

Good thread. I am considering using a new 10 hp air cooled diesel on ebay for $619 and (4) automotive alternators to charge a 48 volt bank. Entire set up should be only $1K and produce just shy of 7kw of charging.

http://www.ebay.com/itm/NEW-10HP-SMALL-DIESEL-ENGINE-WITH-ELECTRIC-START-10-HP-/170672262621?pt=LH_DefaultDomain_0&hash=item27bcdc0ddd

Bob

--- On Sat, 9/15/12, hardy71uk <dottir@hotmail.com> wrote:

From: hardy71uk <dottir@hotmail.com>
Subject: [Electric Boats] Re: 48v diesel telecommunications standby gen?
To: electricboats@yahoogroups.com
Date: Saturday, September 15, 2012, 10:27 AM

I'm thinking of using a 3phase generator . Use three transformers to bring the voltage down to the required value . Make the output DC via a 3phase rectifier. Should make a simple charger.

Chris S
--- In electricboats@yahoogroups.com, Michael Mccomb <mccomb.michael@...> wrote:
>
> other than the Panda stuff which is VERY expensive has anyone come across a 48v dc diesel charging system.... i'd rather use a sort of RAID approach with a much less expensive diesel/PMA system but am pushing the limits of my understanding to devise such a system.... seemingly both diesel engines AND permanent magnet alternators of sufficient power/capacity can each be had for under $1k... some electronics is undoubtedly needed but adding this would still bring a system in perhaps 10k under the Panda price
>
> one can stumble across all sorts of reference to 48v diesel units used for telecommunications systems but i have had great trouble actually tracking such a unit down
>

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