Solar Power

[Naam]

@IMHO and @Crossy,

Thanks for the info.

I do not want to install an other inverter, but I will set the PLC so that I do not discharge the batteries for more then 25% Per direct I will use my solar energy only when I am not home and at night. This will keep the batteries continuous fully charged, and protects enough against failure from our grid.

I always used normal car batteries, I know they are not suitable for this application, but did not have much choice. Life time was more closer to three months. First time I even had 4.000Ah.

Now I have a maximum current from the panels from around 60A, at 24V So charge current to batteries is maximum 6A. Discharge current can be around 12A. I do not dare to say what is the average production in 24 Hour. But when the PLC is running I can tell this. I also want to measure the production from the panels, from the charger to batteries, from batteries to inverter, and from inverter to my 220V installation. I think I may be happy when finally 50% is effective used. When I should design the system again I should use much more 24V lighting systems.

And as you may notice, I do not have any electrical background, i am just very much interested in this stuff.

Regards, Arjen.

One more thing that might be impacting your battery life is the way it's wired... Yep, it all seems pretty simple to do series and parallel wiring, but there's more to it than meets the eye.

Essential reading on battery bank wiring here: http://www.smartgauge.co.uk/batt_con.html

Also,. here's a good read about lead acid voltage and depth of discharge, for your PLC: http://www.scubaengineer.com/documents/lead_acid_battery_charging_graphs.pdf

please explain IMHO

sorry, just saw the explanation but would that apply also to a bank of 2 batteries?

Edited March 9, 2015 by Naam

[Crossy]

please explain IMHO

sorry, just saw the explanation but would that apply also to a bank of 2 batteries?

Indeed it would, the simple diagonal connection will certainly balance up the discharge pattern of even two parallel batteries.

How much effect you would see on a system which is intended as a standby is debatable.

[Naam]

Are they for your UPS systems? In which case would not be discharging every day?

yes, UPS. a total discharge i had only once a few months ago when power was out for 10½ hours. that's when i doubled the Ah capacity of the UPS that serves my TV-room, my study and my wife's study (a total of 3 PCs, 4 PC screens and a 70" TV). by the way, i'm not sure whether it was really a total discharge because the inverter has a function to shut off when a minimum voltage is reached. unfortunately i did not measure battery status nor do i know at what minimum voltage the shut-off occurs.

[Naam]

please explain IMHO

sorry, just saw the explanation but would that apply also to a bank of 2 batteries?

Indeed it would, the simple diagonal connection will certainly balance up the discharge pattern of even two parallel batteries.

How much effect you would see on a system which is intended as a standby is debatable.

thanks, but it won't hurt if i change the wiring accordingly.

[IMHO]

@IMHO and @Crossy,

Thanks for the info.

I do not want to install an other inverter, but I will set the PLC so that I do not discharge the batteries for more then 25% Per direct I will use my solar energy only when I am not home and at night. This will keep the batteries continuous fully charged, and protects enough against failure from our grid.

I always used normal car batteries, I know they are not suitable for this application, but did not have much choice. Life time was more closer to three months. First time I even had 4.000Ah.

Now I have a maximum current from the panels from around 60A, at 24V So charge current to batteries is maximum 6A. Discharge current can be around 12A. I do not dare to say what is the average production in 24 Hour. But when the PLC is running I can tell this. I also want to measure the production from the panels, from the charger to batteries, from batteries to inverter, and from inverter to my 220V installation. I think I may be happy when finally 50% is effective used. When I should design the system again I should use much more 24V lighting systems.

And as you may notice, I do not have any electrical background, i am just very much interested in this stuff.

Regards, Arjen.

One more thing that might be impacting your battery life is the way it's wired... Yep, it all seems pretty simple to do series and parallel wiring, but there's more to it than meets the eye.

Essential reading on battery bank wiring here: http://www.smartgauge.co.uk/batt_con.html

Also,. here's a good read about lead acid voltage and depth of discharge, for your PLC: http://www.scubaengineer.com/documents/lead_acid_battery_charging_graphs.pdf

please explain IMHO

sorry, just saw the explanation but would that apply also to a bank of 2 batteries?

Towards the end of that article, the author explains that for 2 batteries in parallel, the diagonal wiring system (method #2) can't be bettered.

Finally, if you only have 2 batteries, then simply linking them together and taking the main feeds from diagonally opposite corners cannot be improved upon.

Edited March 9, 2015 by IMHO

[Naam]

Towards the end of that article, the author explains that for 2 batteries in parallel, the diagonal wiring system (method #2) can't be bettered.

three of my systems are wired in series (2 x12 = 24V). one system consists of 4 batteries wired in series and parallel (2 x 12 + 2 x12 = 24V).

[Crossy]

This link http://www.scubaengineer.com/documents/lead_acid_battery_charging_graphs.pdf from an earlier post has the necessary graphs to work out when you are at 25% discharge (75% remaining).

You do need to know the discharge rate in order to define the end voltage.

[IMHO]

Thanks Crossy, but the provided link does not work....

Arjen.

Try this one: http://goo.gl/i99A3C

[sammydavis]

it is true about the temperature coefficient but in my experience the panel still work to almost full capacity even when hot.  i think it is something to do with the humidity blocking the infra red.  

[ksamuiguy]

It seems to me that here on Samui an installation on a flat roof would be the best installation.

here customers are concerned with esthetics, basically installations are ugly on most home roofs. this would allow panel orientation  however you needed.

 

[George Bowman]

I have been following this thread and appreciate the advice given. Been thinking about  solar unit for our place outside of Phitsanulok. The first obstacle is the buy back program. The tambon office said the electrical wires for this program have not yet been installed. Could be months or even more. I will check with the electrical company next.

[Crossy]

57 minutes ago, missoura said:

The tambon office said the electrical wires for this program have not yet been installed. Could be months or even more. I will check with the electrical company next.

Talk to PEA, it's nothing to do with the tambon.

 

The buy-back / feed-in tariff does not require any extra infrastructure other than an export meter.

 

Note that if you don't intend becoming a net-exporter (making more than you use) you may be better off just staying with net-metering (meter goes backwards when you are exporting), check the feed-in tariff contract very carefully. You still need the permits from PEA mind.

[free123]

Hello everybody...very interesting facts and like always read the small print...means check details like heat shade dust etc..a lot of variables to a good idea...and i heared that the production of such panels is everything but eco friendly if anyone concerned...my question : did anyone on the forum tried a windwheel...especially those living near the ocean or up north in the mountains wind happens 24 hours.also at night...i would like to learn where here in los we can buy windwheels and find companys who install it all for you ....any experience with this or with combo systems ( wind and sun )

[free123]

5 hours ago, Arjen said:

Combining a wind and solar sytems sounds good. You need different type of chargers. Not sure how it works when you combine and want to connect to the same battery bank.

 

 

there is quiet a bit material on this subject but it mostly concerns central europe where are plenty of companys that can set up one for you...also combo systems...I hope to find a company here in thailand who has the expertise and the experience to set up such a wheel including the tower ( 10 m + height )...but so far no luck...even in thailand there are commercial windparks. but never saw a private wheel...

[free123]

1 hour ago, Arjen said:

Yes, there are. Check "Leonics" in BKK. They are not the cheapest, but give good service, and good quality products.

 

Arjen.

 

 

Hey Arjen...thanks for the info...I just wrote to them lets see if they can do a windwheel

[Crossy]

Leonics certainly make wind and solar controllers / inverters, I don't think they make wind turbines.

 

I'm not convinced about wind at a domestic level in Thailand, in northern BKK we either have no wind or way too much. There are some small turbines near Rangsit station, I've never seen them actually rotating.

 

Solar is, of course, a completely different matter.

[free123]

On 29.4.2018 at 3:15 PM, Crossy said:

Leonics certainly make wind and solar controllers / inverters, I don't think they make wind turbines.

 

I'm not convinced about wind at a domestic level in Thailand, in northern BKK we either have no wind or way too much. There are some small turbines near Rangsit station, I've never seen them actually rotating.

 

Solar is, of course, a completely different matter.

They replied...nowadays they do solar only in the past they did windwheels but encountered uncontrollable problems they told me whatever this means...so solar ok but wind nope