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Old 20-05-2014, 09:13   #1
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Alternative Charging Methods

Hello,

Does anyone think about exploring new alternative methods of charging your batteries, other then Wind and solar ?

I had an idea some time back that I have been experimenting with, and think it's paying off !!

If you have ever tried to repair a 12v fridge, you know about the "Peltier Module" that is a thermoelectric plate. As you put power into it, you get heat on one side, and cold on the other side.

I picked up a few of these Peltier modules. If you put heat on one side, and cool the other side, you actually make current !!!

On the Bertram Sport Fisher, the engines are running all day as we troll offshore. Since the engines are throwing heat from the exhaust into each turbo, why not try to use these Peltier module to create power to charge the batteries !!!

I put 4 around the exhaust pipe after the turbo on one side of the 8V92 Detroit Diesel. Not a lot of current... Then I took some 3/8" soft copper, and wrapped 3 turns around the outside of the Peltier modules. So we have the hot side touching the 320 degree (F), exhaust pipe before the sea water enters. The 3/8" pipe is in direct contact with the cold side of the Peltier, so I connect a flow of sea water into the 3/8" copper pipe, the cool water flows around the cold side of the Peltier, and exits outside the vessel. I am now generating nearly 7 amps.

Since I am in Hong Kong, Mainland China is my back yard. I have a factory making me an assembly ring that will snugly slide on the pipe. They will then properly incorporate the copper tube and encase with ceramic goop.

Has any one else experimented with this concept ?

I have Jabsco sea water pump that run off a belt an the flywheel that pumps the sea water back to the tuna tubes and cockpit wash down. I have more then enough flow to get the sea water from there to cool the outside of the thermoelectric generator !!!

What are your thoughts ?

Alan

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Old 20-05-2014, 09:27   #2
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Re: Alternative Charging Methods

It is a very expensive and inefficient way to recover wasted energy.

My thought is you want a more efficient engine that isn't using 50% of the energy in the fuel to generate heat in the exhaust.

A smaller engine with a turbocharger is one such step.
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Old 20-05-2014, 09:27   #3
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Re: Alternative Charging Methods

Quote:
Originally Posted by Hkalan View Post
Hello,

Does anyone think about exploring new alternative methods of charging your batteries, other then Wind and solar ?

I had an idea some time back that I have been experimenting with, and think it's paying off !!

If you have ever tried to repair a 12v fridge, you know about the "Peltier Module" that is a thermoelectric plate. As you put power into it, you get heat on one side, and cold on the other side.

I picked up a few of these Peltier modules. If you put heat on one side, and cool the other side, you actually make current !!!

On the Bertram Sport Fisher, the engines are running all day as we troll offshore. Since the engines are throwing heat from the exhaust into each turbo, why not try to use these Peltier module to create power to charge the batteries !!!

I put 4 around the exhaust pipe after the turbo on one side of the 8V92 Detroit Diesel. Not a lot of current... Then I took some 3/8" soft copper, and wrapped 3 turns around the outside of the Peltier modules. So we have the hot side touching the 320 degree (F), exhaust pipe before the sea water enters. The 3/8" pipe is in direct contact with the cold side of the Peltier, so I connect a flow of sea water into the 3/8" copper pipe, the cool water flows around the cold side of the Peltier, and exits outside the vessel. I am now generating nearly 7 amps.

Since I am in Hong Kong, Mainland China is my back yard. I have a factory making me an assembly ring that will snugly slide on the pipe. They will then properly incorporate the copper tube and encase with ceramic goop.

Has any one else experimented with this concept ?

I have Jabsco sea water pump that run off a belt an the flywheel that pumps the sea water back to the tuna tubes and cockpit wash down. I have more then enough flow to get the sea water from there to cool the outside of the thermoelectric generator !!!

What are your thoughts ?

Alan
Attachment 81630
Is this meant as an alternative to an engine driven alternator or a supplement? Does your engine driven water pump consume more engine power than an alternator or less? How many of these do you need to stack up to give 100 amps? Also since these are extracting heat from the exhaust to make electricity what is the temperature drop per module? How many can you stack before the exhaust temperature gets to low to generate significant power. I assume you are stating 7 amps @ 12 volts or are we talking some other voltage?
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Old 20-05-2014, 09:33   #4
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Re: Alternative Charging Methods

When I read your first few sentences I thought no chance and if you have a V8 diesel then why not just put a 24v school bus alternator on it. However, if your generating 7AH well now perhaps that can be used on a yacht under engine power, or for those of us 50N around the diesel heater, that could generator more power than it consumes.

Any photos of the set up?

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Old 20-05-2014, 20:53   #5
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Re: Alternative Charging Methods

nobody really needs more power while engines are running. that's what alts are for. bigger alts / ext regs are way eaiser then what you are trying to do. people need alternate power sources while anchoring and sailing.
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Old 21-05-2014, 03:06   #6
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Re: Alternative Charging Methods

Hello,

I realize at anchor is the time we need and consume most. I am looking at my power situation when we go fishing as well.

On the Bertram 46.6 sports fisher, we are trawling at 7 knots. We have a 32v alternator on each engine. There is the belt driven Jabsco wash down pump on the port engine, that throws sea water to the cockpit for the Tuna tubes, and washing off the fish blood... A lot of pressure and high flow of water.

Why put more alternator load on an engine to consume more fuel for a 12v bank that powers my radar, structure scan, fish finder etc... Why burn more fuel for the generator to charge the 12v, as no one is in the saloon needing Air Conditioning on the AC side because we are on deck fishing.

I just thought this would be a good way to make use of the sea water pump that is already running off the engine, and we sure have enough heat on the exhaust pipes.

Saving fuel consumption and lowering emissions is a global idea to many. I spend enough every year to keep the engines healthy and do my best not dump un-burnt fuel or oil into the air. I like fishing and should still be responsible ! Just my personal preference.

This is just a thought for a fishing boat !

So far I am getting good results with the engine at idle, the exit side of the turbo exhaust pipe is at 360 degrees F at idle. The Sea water is 68 degrees F. The set of 4 modules is currently producing 8.1amps at 13.62v today. This is my 26 working attempt. Each time it improves !

I ordered the TEG thermoelectric modules that can handle up to 800 degrees C.

I'll still post some pictures when I have a clean and well functioning system.

Thanks for your feedback !

Alan
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Old 21-05-2014, 06:45   #7
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Re: Alternative Charging Methods

This is interesting; as somebody else mentioned I live and sail mostly south of 50 (where the numbers increase as you go south ) and often have a diesel heater (Refleks) running for a major part of the day.

My idea with peltier blocks, as a first step, is to make a new hotplate for the top of the stove sandwiching the blocks between a heat-plate on the bottom and a heat-sink with fan on top.

What is your source of Peltier blocks please?

I already have had good success with the ecofan peltier driven fans to move the warm air around the cabin.

Depending on the cost I'm not sure if the exhaust method is value for money but congratulations on looking at green generation methods. If your alternators can be backed off 7Amps because the current from your peltier system is being fed to the same charge controllers > Your engine load is decreased by that amount (the exhaust may cool slightly but lests assume for the moment that is doesn't) then for a given engine load you have a net gain of the power equivalent of 14 Amps.. that is significant current.
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Old 21-05-2014, 07:00   #8
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Re: Alternative Charging Methods

Hello

I am using TEG modules, not TEC.

The TEC are used for cooling. The TEG module is for power generation.

I will be making 35 to 45 charging amps on each engine.

Alan
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Old 21-05-2014, 18:35   #9
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Re: Alternative Charging Methods

Thanks.. and where do you get your TEG modules from? Do you have a recommended supplier?

Chris
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Old 21-05-2014, 18:56   #10
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Re: Alternative Charging Methods

Hello,

I live in Hong Kong, and I have been trying several different suppliers in Mainland China.

I can't recommend one yet. One must be quite diligent about communicating to factories or even on eBay. Many say they are selling you a TEG module, when it is actually a TEC module that arrives at your door. The TEC module and wires cannot handle the heat of an exhaust pipe, or even a hot surface above 300 degrees F for a long period of time. The TEG modules are very robust and the wires are much thicker and have Teflon coating.

I just paid $23 USD each for...

TEG-12640-15 CMO Thermoelectric Power Generating Modules
Open circuit Voltage: 8.8V
Load output Voltage: 4.2V
Load output Current: 3.5A
Load output Power: 14.7W
Heat flow through: 350W
Internal resistance: 1.2 Ohms
Dimensions: 40*40mm

Calcium/Manganese (CMO) TEG modules up to 800 degrees C, hot side !

CMO materials are extremely stable and will last up to 50 years with little or no degradation.

See where it says in the model number "126" (TEG-12640-15). That is also important. That is an easy way to see it is a TEG module. If it says "127" then they are selling you a TEC module designed for cooling. Not a TEG module for power generation.

It is a fun project, and I was able to see that I needed to give some extra attention to a few issues at the back side of the engines from spending the the additional time in the engine room for this little experiment... LOL

Alan
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