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Mertz
Starting Member
USA
42 Posts |
 Posted - 31/12/2007 : 20:56:20
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Since I need 24 volts to operate a Outback grid tie inverter can I use a voltage booster to get from 12v to 24v? What are the draw backs?
Mertz
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ghurd
Junior Member
USA
304 Posts |
Posted - 02/01/2008 : 02:17:10
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It would cost more than replacing your existing windmills.
The efficiency would be low. The cost would be high.
Grid tied Ametek-style windmills would be an exercise is wasted money.
The money saved would never cover the grid-tie and maintainence costs.
Even if it put out 50W 24/7, (and it will not) it would save about $7 a month???
Some places the company charges $20 to read the extra meter. Thousands of $ in 'stuff', lic'd electrician, etc, to lose $13 a month?
They might not allow the windmills to be grid-tied because they are not UL listed as windmills. Depends on who you ask, and which inspector and code guys you happen to get.
Depends on where you live too, but that's the idea. Grid-tie has to be big to be worth considering
G-
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Mertz
Starting Member
USA
42 Posts |
Posted - 02/01/2008 : 15:58:17
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I my area the inverter needs to be UL rated not the windmill. There is no other fee other than the initial cost of the reverse meter which is $150. In Washington we have a program where the utility has to buy back excess power at twice to 4 times the rate we pay. Using an Outback inverter would get me a $0.33 per kwh payback. I pay $0.056 per kwh.
What are other people doing with their generators to use the power? I want to make it useful.
Mertz |
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ghurd
Junior Member
USA
304 Posts |
Posted - 02/01/2008 : 18:59:28
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CFL lights, TV, computer, etc.
It doesn't cost much that way. Inexpensive inverter of reasonable quality from eBay, couple used 6V T-105s from the golf course. Should cost a lot less than the reverse meter.
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Mertz
Starting Member
USA
42 Posts |
Posted - 03/01/2008 : 20:32:29
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I found a DC converter that puts out a regulated 12 or 13.8 volts with a 4.5 to 10.5 volt input. It has a 180 watt peak short duration capacity. This would work to produce the voltage I need to charge batteries at very low wind speeds. The rep says it is regulated output voltage. The problem is that he doesn't know what will happen to the unit if it gets too much voltage. I need something to cut out the voltage at something like 12 volts or a diverter to send the 12 volts to the battery instead of the converter. Would a relay work? An if so how is it wired? BTW the unit is $140.
Mertz |
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DPMeters
Starting Member
United Kingdom
6 Posts |
Posted - 04/01/2008 : 17:27:49
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Hello Mertz
You could put a power diode in parallel with the booster circuit, once the incoming voltage is higher than the circuit under charge the diode would conduct therefore bypassing the booster. This would of course waste power slightly, Watts = Amps x diode volt drop, sadly the incoming voltage will still be above 10.5v for the booster. Using a double pole bypass relay across the booster and cutting out the feed to the booster with the second set of contacts would be better as it will cover the overvoltage too :-) To get the relay to operate at say 10 volts you could use a 6 volt relay and a 5v1 or larger zener diode in series with it across the incoming supply so that the relay 'pull in' voltage would be around that 10.1v to 10.5v area....needs a little experimenting as the relay 'pull in' voltage is not known exactly....just because it says 6volts is not strictly true.
I would prefer to use a 9v to 36v input booster, they usually start working around 8.5v and the input source should have some power behind it at 9v.
Don't forget the power available when the input is 4.5v will be pathetic (unless you are using a low impedance source such as batteries) and as the booster switches on it may collapse the incoming voltage below 4.5v so the booster stops working again.....it would then just oscillate between on and off and nothing will be seen except a $140 hole in your account !!
This is not as simple as it sounds and we are working on this now, there are other issues as to the hysterisis of the switching when close to the booster cut off point and the relay hysterisis too....sorry to be a pain but spend your money elsewhere for now ok :-)
Please note any info given is in good faith and for help only ok :-)
P.S. If this all sounds like waffle don't worry, I will do the wondering for you if you ask nicely :-)
Regards. Peter |
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DC boosters
