DUMP LOAD ???

[2windy]

What is an easy and cheap way to make a dump load for my C-40 I have a 12volt wind genny system that is producing more than I can use at the present. I am getting 20 to 40 volts  and 10 to 20 amps, some days even more and of course some days none.I read about the water heating elements, but it is summertime now and would like something besides heat if possible. Would more batteries and another controller be the only answer for lighting. Its what I am using my battery bank for now.

[phil b]

I also have a 12 volt system with 2 C-40 controllers. One is set on load control (on at 14.5V, off at 12.5V) and the other diverts the load at 13.5V. The diversion usually controls the system well at below 15 mph.

I used some ni-chrome wire wrapped around a piece of ceramic pipe for a dump load. Same stuff used in electric heaters. It was purchased from E-bay for about $.80/ft.

There are a few places on the net that sell 12 volt water heating elements. I haven't tried them. They look like an item made to sell, not to use. Just my opinion.

You might use the load control mode to run a Coleman refer. I tried that and it does work.

More batteries are always a good choice.

[DanG]

Portable coolers & friges that use peltier junction thermoelectric devices will soak up alot of current draw but they do not last forever. 500 hours run time would be a maximum estimate, I have used several TE coolers to flue cure tobacco in. The Coleman service online sold the module preassembled in heatsinks for $28 last time I repaired one.

[Opera House]

Summer......Run some fans.

[asheets]

Side questions:  would an electrolizer make a good dump load?  I mean, take a bucket of water, stick 2 stainless steel bolts into it, and dump excess DC into it (generating hydrogen and oxygen gas, of course).  

Might not be very useful in winter, and you'd have to top off the water every once in a while.  Plus, you'd have to either vent or capture the gases properly (to keep for incurring a nasty explosion).  But it seems to be as good an idea as a set of heating elements of lamps...

[craig110]

Hi 2Windy,

While more batteries are often a good choice, I disagree with Phil B's statement that more batteries are always a good choice.  If the situation is that your generator is putting out more power per average day than you are using per average day, adding more batteries just means that in some number of days or weeks you'll have a larger bank of fully-charged batteries and you'll be back to looking for a good dump load.  Skipping the beneficial effect on the depth of discharge, adding batteries just lets you go for longer periods of time when the generator isn't producing.  You didn't say anything about the batteries getting discharged, though, so this doesn't sound like your problem.

Ditto using the extra water to produce hydrogen and oxygen.  If your only use for the gases would be to generate electricity for your use, the gases would be acting like additional batteries and, as with normal batteries, if your windmill is already producing more than you need over the long-term, you won't need to tap into the gases.  On the other hand, do you have a neighbor that would be interested in getting a hydrogen fuel-cell generator?

Even though it is getting into summer, I wouldn't ignore using the extra power to heat water.  I don't know about you, but unless the temperature is well into the 90s I still like to take hot showers.  If I wasn't planning on going grid-tie soon, I'd use our water heater as a nice year-round dump load.

Craig

[Ungrounded Lightning Rod]

Have you considered air conditioning?  You can dump a LOT of power with that.  B-)

[Countryboy]

Run a string of DC light bulbs for a quick and easy dump load.

Automotive taillights are dirt cheap, and eat about 25 watts each.

[BT Humble]

Run a string of DC light bulbs for a quick and easy dump load.

Automotive taillights are dirt cheap, and eat about 25 watts each.

Halogen globes that fit in kitchen "downlights" will use 50W each.  The type that have just the bare bulb with no reflector are cheap (about AUD$0.50 here), and coincidentally the pin spacing fits perfectly into the power connector from an "ATX" PC power supply:

(More images here.)

BTH  

[nothing to lose]

Build an electric lawn mower, use the dumped power to keep it charged. If it is charging full too often, mow more often

Just find more uses for the extra power for when you have it available and that you don't care about when it's not available.

If you heat in winter with wood, then use an electric chainsaw to cut wood durring times of excess power.

"Would more batteries and another controller be the only answer for lighting. Its what I am using my battery bank for now."

NO, sounds like you need to use the bank for more stuff. Is lighting the only thing you use electric for? What about TV, Computer, Stereo, Frig, fans, washer, deep fryers, ect... If you keep the bank a little below full you won't need the dump load often, then using a heater just when seldom needed would be a fine dumpload for safety even though it's wasting power making heat you don't want since it would rarely be on.

[Scotth]

Someone posted a dump load he made out of some copper water pipe and an old stove or hot plate element.I believe the post was titled "having a good dump"???Anyway,I built one the same way using an old drier element cut up in place of the stove element.It works great.I tested it last week when the mill was putting out 60 + amps and the load slowed it right down and heated up nicely.Total cost was 8 bucks Canadian for the stainless screws,everything else I had lying around.

Scott

[jimovonz]

http://www.fieldlines.com/story/2006/2/28/114556/473

Good to see that this was useful!

[Scotth]

Useful?you bet-and low maintenance to boot.Thanks for a great idea.

Scott

[willib]

jim your avi still doesnt work

and about your kicker

would it be prudent to disconnect the f&p from the output till the blades start turning?

[jimovonz]

Hey willib. Unfortunately some folk are having trouble watching the video I posted - though other folk are not. I don't currently have any software installed that will allow me to convert the format - its straight from my digital camera. The alt should be quite happy producing power while connected to the circuit I described. As long as Q1 is normally 'off' (i.e when the alt is producing power) then there is no current path. Q1 should only be 'on' during the actual kicking phase.

[dinges]

Personally I like old car headlights, 12V/55-60W. Or 24V, if that's your system voltage. I usually get them for free at a garage because normally the 'dim' lights burn out. Main beam still works usually.

Put as much as you need in parallel to get the amount of watts you need to dissipate. Add some extra, in case one or two burn out. Make sure there's plenty of ventilation. I managed to make a burn in the carpet in the garage once. And wear shades

I also use such bulbs for testing large 12V powersupplies. Works fine, just don't look into the light.

Peter.