connecting solar panels together

Hi ben and all little gotwinds
its been a while since i posted here anything but just been quite busy with work, anyway here's my question:
since i now bought a 600 watts grid tie inverter (the ones that connect to your wall socket), i have connected my 140 watt solar panel and my 50 watt to it, (nice bit of kit by the way), however I have reservations on how I have everything connected all the negatives and positive from both panels connected together, i also have another 140 watt panel arriving on monday so the total will be 330 watts but here is my question?
do i need blocking diodes on each positive wire in each panel before it meets the inverter so in theory all the juice will be going forward, just i read that the bigger panels (140 watts) could destroy the smaller one (50 watt).
Also I am wondering since i have this inverter and really don't need batteries anymore, should i sell all my equipment which is as follow:
7 batteries 105 amp each
2 jutas 16 amps charge controllers
1 600 watt modified inverter
1 1000 watt pure sine wave inverter
and maybe spend all the profit on another 2 or 3 ( 140 watts) solar panelsand end up with 600 watts solar system.
Really i just want peoples opinion since i could really do with the extra space in the shed but I look at every item and don't want to get rid of it.
But i would be happy with the 600 watts FE turbine and 600 watts solar power.
see u guys
super windy

I think it would be best to use some diodes. Certainly if one panel went into shade the other panels would feed into it.

The whole point of grid tie (for me anyway) is that you do not need batteries and charge controllers, so I would say sell it all and buy more panels.

What type of grid tie have you got? Would be interested to know a little more as I'm looking at getting one myself.

cheers buddy
can you point me out to the best diodes for this, since i am not very electrically minded :oops: , i have done a little test where i shaded the 50 watts and power still comes out the 140 watts and then shaded the 140 watts and still the power comes out from the 50watts, so maybe the diodes inside the panels are doing their job and i might not need the diodes, what do you think, maybe my buddy Mr ghurd can solve this issue .
The grid tie inverter is a new one that i am hopping to sell on my site, after i tested it myself for a while, you can use wind and solar up to 600 watts and voltage starts from 14v to 36v dc, and so far i am very happy with it, I am on the british gas energy smart deal where you get an energy monitor and it shows how much power you are using and i love turning the inverter on and seeing only 90 watts on the meter and if i turn it off goes up to 270 watts, so its working and i am hopping to do a video when i get a chance.
cheers
humbertini/super windy
www.windchasers.eu

Yikes! 270w :shock:
My house when everything is switched off bar the stuff on standby uses 35w :mrgreen:
When the new eco fridge freezer cuts in it jumps to 100w. But if its a sunny day the meter just stands still with my 120w of solar grid tied. ;)

Does your meter spin backwards SW mine doesn't. :(

If your panels already have diodes built in then no need to add any more. If you did need diodes, I believe Schottky diodes are the best to use.

cheers guys
shawn how are u buddy, the 270 watts is the big tv that the kids always seem to have on and the wii , everything except fridge off is 98 watts continous however once i get the other solar panel hopefully it will go to nil or almost nothing comming in from the grid.
I think that my meter is a newer digital display meter and I don't think it will go backwards I am hoping for big wind to see what happens has I can easily make 400 to 500 watts with the big turbine and that will be a big test for the inverter and hopefully I will see what happens to the meter.
I am just scared off blowing up my electrics in the house almost every 2 weeks I am buying stuff and the wife keeps asking me whats that then :roll: ????, I just tell her that I really need it and it makes me very very happy, and without this the world will end ;) .
see u guys and hopefully I will get a big wind day to really test the inverter . ;)
super windy
www.windchasers.eu

I think it would be best to use some diodes. Certainly if one panel went into shade the other panels would feed into it.

Probably not.
To back feed, it takes quite a lot of voltage over the PVs open voltage at that time.
If the unshaded PV is connected to something at about 14V, then it is probably operating at less than 15V.
A PV with half the cells completely shaded (like with a sheet of plywood type of shading) should still be a hair over 10V.

Shade from a tree will certainly reduce the output current compared to the unshaded panel, but the individual open voltage of parallel panels (if separated) would be close to the same in most real world conditions.

A diode on each will not hurt most normal systems. It only VERY slightly reduces the output.

For a Chinese GTI, hard to say what will happen.
Most of them use a form of MPPT, or pseudo MPPT.
Many of them will not GT until the DC is above 14V. And IIRC some of the Juta controllers may regulate at 13.8V? Meaning the GTI will never get up to doing what it does?

If the grid goes down, will need some kind of a snubber circuit to keep the GTI from blowing up if wind power is included.
G-