Gordon DeBower's posts

I'm confused how 120 volt grid tie inverters work with the household 240 volt grid. I know how the grid works with (2) 120 volt legs out of phaze, leg 1 to neutral gets 120 volts, leg 2 to neutral gets 120 volts, accross the 2 legs gets your 240 volt. So if you have (1) 120 volt grid tie inverter plugged into one leg will that work? Seems like it would only feed to loads on that leg. And can you feed just one leg back to the grid? Or do you have to have (2) 120 volt grid tie inverters, one to feed each leg of the grid?
Right now I have an outback setup, one VFX3648, I charge batteries and feed a few dedicated loads. My thought was to change to a battery backed up grid tie system with one GTFX3048, but is that possible? Or would I need to get two inverters? Any help would be appreciated. Thank you.

Thanks for some more good info.

The Trojan dealer I spoke with also carried US Battery, but they didn't have eight in L16 or a golf car size, and since they had to buy them by the truck load they didn't know when they would have at least 8. Plus they claimed the Trojan's were a much better battery. But who knows, that could just be them steering me towards what they had.

At this point I'm leaning towards the Trojan's, partly for the convenience of a local dealer, vs. having to borrow a truck and blowing half a day going to get the Interstates.
But I don't want to go with 16 batteries, one, I only built a battery box big enough for 8, and two, that would be quite a change to come up with.

I got the system on-line mid September, and at that time I only had 1000 watts worth of panels. Even then I was pulling close to 4KWh a day, and that was with a small shading issue, a pine tree that will be removed soon.

Thanks again for all the info.

Dave:
Yep, I've got my homepower subscription, recent loyal subscriber. I was looking at the battery buyers guide in the Oct/Nov 2008 issue, and it failed to mention Interstate, but I do see now that it lists US Battery. On the surface it looks like the Interstate / US Battery has better specs as far as number of cycles.
But once I get home tonight I'll be sure to pour over the host of info you supplied.
Thank you so much.

Ken:
Well its a 48 volt system, and L16's are 6 volt, so yes that would require 8 batteries.

I guess the main point of my question were:
1) Are the Trojan batteries worth the extra cost? Rechecking its $55 a piece extra. Will they last longer, be more reliable, will I get more cycles than I would with the Interstate batteries?
2) Will my 1300 (eventually to be 2000 watt) array be enough to maintain L16's? or should I use a smaller battery like a T145? Keep in mind I'm located in Central NY, a good day for me this time of year is 2Kwh, and zero production days aren't uncommon.

System setup is handled. I only have select non-essential loads tied to the outback power panel. I'm not trying to get off the grid, the solar just supplements my electric supply. Between the solar and conservation I have cut my grid dependence in half, imagine if everyone could do or did that...
 
Right now I have the inverter set to run solar until the batteries fall to 50% when it will then seamlessly switch the loads to the grid, once the batteries reach at least 75% then it automatically toggles back to the batteries. And note that I do not charge the batteries from the grid, the loads just switch to grid power and stay there until the solar brings the batteries back up.
Once I get new proper batteries I will probley bump up the set points to a shallower depth of discharge so to take it extra easy on the batteries and get as long a life span as I can from them.

So if anyone has any opinion or data on Trojan vs. Interstate bang for the buck it would be appreciated.
Thank you.

I'm torn between price and distance to travel. Interstate dealer is approx. 30 miles away, about a 1 hour trip, and Trojan dealer is less than 2 miles away, about a 5 minute trip. In the L16 size the Interstates are about $40 cheaper.
Are the Trojans worth the extra money?
I have an Outback system, 48 volt, VFX3648 inverter, MX60 charge controller, 1340 watts worth of panels. My plan is to add another 680 watts of panels this summer to get up to 2020 watts. And it's Not a grid-tie system. Just to get the system up and running I hooked up (4) 12 volt Marine/RV batteries that were lent to me, they are useless and need to be replaced asap, they severly limit the system right now.
So another question, with my realatively small amount of solar should I go with a smaller battery? say like a T145?
I have no real goals as far as production, I just use whatever I can make, when the solar isn't there it just switches back to the grid. Basically the solar suppliments my electric use.
Any advice would be appreciated, Thank you.

I've put together a smallish system, 1000 watts of panels (specs) arranged 2 series strings of 500 watts each, 48 volts, < 15 Amps, MX60 charge controller,... Can anyone suggest charge controller setting for bulk, absorb and float voltages for my batteries? Also equalization voltage & time? I've got (4) Exide Stowaway ST27DC-180 batteries. Their web-site is no help, and I've called the consumer phone number twice, left messages, and have never gotten a reply.
Any help / suggestions would be appreciated, ty.

I'm putting together a small'ish system, I already have panels, eight Mitsubishi 125 watt panels (17.3 max volts, 7.23 max amps). Keeping in mind my plan is to expand the system over time with the addition of more panels. I'm not interested in going grid-tie at this time, I know I'll have no problem using up the little bit of power I'll produce.
So I am looking for recomendations of charge controllers and inverters. How should I wire the panels? I wanted to just make one series string of 138.4 volts, but it looks like I would be limited on charge controllers that can handle that voltage. My hope is to add another 1000 watt string of panels next summer.
What if I can't get panels with the same specs or voltage? Would that be a problem? It would be nice to get a charge controller that would handle additional panels without having to add a second one or upgrading.
How big of a battery bank could I realistically charge? my thaught was eight 6 volt cart batteries, I know someone that can give me a good deal on some.
I'm not looking to supply all of my energy needs, just suppliment, I'm looking at this kinda like a new hobby...
Thank you in advance for any advice.

Okay, well then can I use a grid-tie style of inverter and just not sell power back to the utility?
I happened upon "bob's solar blog" on the net, and his system as he seems to be describing it is what I'm looking for. I make and use what power I can, and any additional power that I need above what I produce I just pull from the grid. I want it simple and automatic without any switches to have to manually control.
Thank you again for any additional info.

More specifically what I'm asking,
Is it possible to make a system where the inverter and grid interact without having to do a grid-tie system?
For example: say at any given moment the house needs 1200 watts, but the inverter can only deliver 1000 watts, can the inverter be used to supply the 1000 watts while the extra 200 watts come from the grid?, or would the system have to switch completely to grid power until the demand falls below what the inverter can supply?
Clear as mud?
Thank you again for anyones feedback.

My apologys if this has been asked before.
What I would like to do is start out small and maybe expand as time, budget, interest, success,... allow. I have a south facing porch roof with enough room for approx. 1000 watts worth of panels. Phase one I wanted to be just the panels and an inverter. Can I just suppliment my electric use this way? I'm not interested in the hastles of grid-tie. I believe I have read about inverters and/or controllers that have dump-load capability so if I'm making more electric than I'm using at any given time I'd just like to dump into a dump-load.
So is a setup like this possible?

My future thaughts involve addition of more panels, I have a west facing roof face with room for probley 2000 watts. I'd also like to maybe do something with wind. I want to at some point add a charge controller and some batteries,...
Any help/advise would be appreciated, Thank you.