solar dump quesion

[snake21]

hi friends,small questions to clear doubt.thanks for replying
if solar panels are connected to batteries and the batteries are fully charged, does the power need to be dumped?i understand that for wind power,the power should be dumped so as to prevent the turbine from over spinning to self destruction.what will happen if the solar panels are being disconnect as the batteries are fully charged?

[madlabs]

No need for a dump load. The controller can just disconnect the panels when the battery is full.

Jonathan

[DamonHD]

Disconnecting panels to avoid overcharging the battery is OK, and indeed is a common thing to do.

Rgds

Damon

[snake21]

i have 1 idea in mind.i am currently using ghurd controllers as dump controller.i am intending to buy a small grid tie inverter.instead of disconnecting the panels after the batteries are fully charged,i would like to feed the excess power in grid.

can someone tell me how can i achieve this using ghurd controller?

if this is possible,then how is it being done?

i want to use this grid tie inverter.   http://cgi.ebay.com/300w-GRID-TIE-POWER-INVERTER-14v-230v-solar-wind-panel-/380269780779?pt=UK_Gadgets&hash=item5889d85f2b

thanks

[DamonHD]

As far as I can tell there is *no* UK-legal G83-compliant grid-tie inverter smaller than the Soladin 600 at a nominal 600W and 45V minimum input voltage.

I'd be happy to be proven wrong.  I'll place an order.  I'd even have a Part-P electrician wire it in having asked my DNO if they objected to my connecting it (ie all completely legal and above board at some cost to me).

I also would like to dump the excess from my 12V off-grid system via a grid-tie when my batteries are full alongside my 5kWp on-roof grid-tie system (ie there's no question that it couldn't be safe even if the export meter numbers might start to confuse the bean-counters after a long while even though I wouldn't expect to be paid for this export/'spill').

Ghurd's controller might have no direct part in any such scheme: you'd probably connect your panels directly to the input of the grid-tie inverter when the battery was full, and allow the grid-tie inverter to suck all the energy from the panels (but not from your battery), ie upstream of any blocking diode.

Rgds

Damon

[Cary]

i purchased one of those (with n American specs 14-28dc  v in 110c ac  out) you cannot hook up to 12 volt batteries.. must be 24 volt
 you can hook up to 14 volt solar panels just not batteries
 ( i believe the input is too low to save from draining the batteries
(  nice feature but you may need to redo your battery  configuration)
make sure you contact them first to see if you can get in your voltage specs..
 

[ghurd]

i purchased one of those (with n American specs 14-28dc  v in 110c ac  out) you cannot hook up to 12 volt batteries.. must be 24 volt
 you can hook up to 14 volt solar panels just not batteries
 ( i believe the input is too low to save from draining the batteries
(  nice feature but you may need to redo your battery  configuration)
make sure you contact them first to see if you can get in your voltage specs..
 

I know some with those same specs have been hooked up to 12V batteries, and they were apparently designed to be hooked up to 12V batteries.
They change the specs frequently.  The part that stays the same is the resellers do not understand what they were designed to do, and often provide faulty info about their intended application.
G-

[snake21]

hi ghurd.remember  i ask if i can charge a secondary battery using your controller?then you suggest to use an automotive relay?

what if i use the same config but instead of dumping excess power to a secondary battery,i dump it using the grid tie inverter?

will that be ok?

[ghurd]

I do not have any direct, hands-on, experience with the little grid tie inverters.
I have done a lot of remote work on them.

It seems like-
The typical Chinese cheapies rated for 14 to 28V could be directly connected to a small second 12V battery.
They seem to be OK with a solar panel and no battery.
They do Not like to be connected directly to a wind turbine.

They frequently change the designs.  The newer units may be very different than the ones made a year ago.
It would be best to contact someone who knows how it is designed, but that does not seem possible, and the resellers of the units do not understand how they are intended to actually work, and as of about a year ago, the information supplied with a majority of the units is completely incorrect.

Nobody can be sure what version you will buy, or how it is intended to work, or what was changed for the same model last week, so no one can answer what will be OK.

[jomac_uk]

As far as I can tell there is *no* UK-legal G83-compliant grid-tie inverter smaller than the Soladin 600 at a nominal 600W and 45V minimum input voltage.

I'd be happy to be proven wrong.  I'll place an order.  I'd even have a Part-P electrician wire it in having asked my DNO if they objected to my connecting it (ie all completely legal and above board at some cost to me).

I also would like to dump the excess from my 12V off-grid system via a grid-tie when my batteries are full alongside my 5kWp on-roof grid-tie system (ie there's no question that it couldn't be safe even if the export meter numbers might start to confuse the bean-counters after a long while even though I wouldn't expect to be paid for this export/'spill').

Rgds

Damon

As far as ive managed to find out, having a G83 compliant Grid Tie Inverter is only applicable if you intend to sell the electric BACK to the grid. For the benefit of UK members a good starting point is this site here, who buy and sell electric   

http://www.greenenergy.uk.com/SellUsYourEnergy.aspx

Its not part P electricians that are allowed to install a grid tie invertor, if you plan to sell the electric back, the equipment AND the installer HAVE to be MCS approved (Microgeneration Certification Scheme) More info here

http://www.microgenerationcertification.org/

Its a VERY viable route to go down, not only can you get a grant of upto £2000 for the installation, the UK government actually pay you in excess of 41p for EACH unit of electricity you generate, NOT export, you are actually paid to generate and USE your own electricity!!!!!

[DamonHD]

G/83 on microgeneration equipment is necessary to *connect* to the grid legally (unless your DNO waives the requirement and (say) G/59 does not apply; selling or not is irrelevant, since it's a safety and control issue.

AFAIK.

Rgds

Damon