Off-grid and grid-tie FREE calculator tool???

[sensei]

Hi, I'm new on this forum and relatively new on the solar power scene. I'm working for a large international NGO, which is to establish grid-tie and off-grid solar power solutions in developing countries. The solutions will range from small off-grid (stand-alone) 60W 12 V DC nominal to large 30kW AC 240/400 V off-grid and grid-tie solutions. To establisg specifications for suppliers, we need a design tool to calculate load, wh/day, powerbank/battery size, inverter and charge control size and types, panel W sizes and other relevant issues. Now, where do we find a FREE reasonable easy-to-use calculator, which will take the most significant issues into consideration and at the same time provide us with a reasonable precise answer to our questions?

Thank your for your urgent help, much appreciated.

Cheers

Sensei

[Naptown]

Off grid calculator excel 97 version (2).zip

this is one for off grid you need to identify location, insolation and load and this does much of the work for you.

[sensei]

[ATTACH]2381[/ATTACH]

this is one for off grid you need to identify location, insolation and load and this does much of the work for you.

Hi Naptown, thanks a lot. However, I'm unable to access the link, because it get this message:

"To view attachments your post count must be 1 or greater. You currently have 0 posts."

I'm not sure I understand this as I do have 1 post..... maybe the facilitator can help?

Cheers

Sensei

[Naptown]

Hi Naptown, thanks a lot. However, I'm unable to access the link, because it get this message:

"To view attachments your post count must be 1 or greater. You currently have 0 posts."

I'm not sure I understand this as I do have 1 post..... maybe the facilitator can help?

Cheers

Sensei

try again

[sensei]

Great tool, thanks!

Some questions:

Max charge current FLA Max charge current AGM
1416,67 177,08 354,17

As I read the calculation, a 12V AGM battery lasts for 1 days of autonomy = load of 3400 wh/day. Why do you divide 1416,67 with 4 to get the AGM AH? Have there been taken any loses/efficiency factors into consideration in the calculations, e.g. inverter efficiency (read that 85% is common) and battery efficiency etc?

Cheers

/Finn

[Naptown]

No that is the maximum charge rate for the battery. you can only charge a battery with so much current. With an AGM you can use a c/4 charge rate where C= Amp hour capacity at the 20 hour rate.
notice that the charge rate for a flooded battery is much lower as these do not like high charge rates as they will boil the electrolyte out of them.
the calculator is based on 2 days of autonomy to take the battery down 40% at 2 days You dont want to discharge more than 40% and 20% on a daily basis If you want two days till a 20% DOD then multiply the AH on batteries by 2
The numbers you were referring to are the AH of the bank that is required, the maximum charge rate of a FLA battery and max charge current of an AGM battery.
If say you were building a system in seattle where there is say 2 KW m2 per day of insolation you would change the sun hours to 2
look at what happens to the array size and the charge rate.
In the one that is sent at 3.5 hours you could use either battery type but change the sun hours to 2 and you are forced to use an AGM or double the battery bank size.

[creativo]

thanks for the explaination...

[sensei]

Hi Rich, thank you very much for your explanation. I have made a calculator (excel chart) - are there any way to upload a document - I would be extremely grateful if you or another knowledgeable person would look at it and correct it where required, as I'm not totally confident.

Cheers

/Finn

[Naptown]

Hi Rich, thank you very much for your explanation. I have made a calculator (excel chart) - are there any way to upload a document - I would be extremely grateful if you or another knowledgeable person would look at it and correct it where required, as I'm not totally confident.

Cheers

/Finn

Yes
go to reply to thread
Look for the icon at the top that looks like a paper clip and click on it
Click the button to add files at the top
Choose your file and add
Once in the box below drag it to to bottom box and click insert inline then done.

[sensei]

Hi Rich, thanks - I tried several times but it keeps on saying 'invalid file'...... Any idea what's wrong? I wanted to attach an excel file.

Cheers

/Finn

[sensei]

I can attach jpg files, but not live excel or word dics... strange ... anybody knows what I'm doing wrong?

Thanks

/Finn

[inetdog]

I can attach jpg files, but not live excel or word dics... strange ... anybody knows what I'm doing wrong?

Thanks

/Finn

Are you using the paperclip attachment tool and uploading the file from your computer before trying to attach it? It will handle a pdf file for me just fine. Possibly it is also qualified by new versus regular user status?

The image and video tools in the next row down are limited in the file types that they will accept.

[sensei]

Hi again, I have now attached the excel chart as a pfd file as it seems attachments are limited to: bmp doc gif jpe jpeg jpg pdf png psd txt zip files. I will try and zip it also.Would be grateful if one of you knowledgeable experts out there would give it a glance and provide some feed back.

Thanks a lot

/Finn

[Naptown]

Hi again, I have now attached the excel chart as a pfd file as it seems attachments are limited to: bmp doc gif jpe jpeg jpg pdf png psd txt zip files. I will try and zip it also.Would be grateful if one of you knowledgeable experts out there would give it a glance and provide some feed back.

Thanks a lot

/Finn

I have no idea what that is about. If off grid and you are using the average insolation figure instead of the worst month then plan on being in the dark a good bit of the year.

[sensei]

Sorry the scanned document is distorted and makes no sence as it appears. Yes you are right about using an average value / we will go for the value of the least productive month. i tried to zip the file, but so far without any luck

Cheers

&Finn