Solar power - how does one begin

[ToxicBunny]

I've been contemplating doing something similar for a while. Especially since I'm doing major renovations at home.

 

[wetkit]

@supersunbird.

Right, so 500W for 12 hours = 6 000wh

Lets say you going 24V DC.
So 6 000/24 = 250Ah.
Now you can never draw 250Ah from a 250Ah battery, as they will not last long, so you need to double capacity to make sure your battries would last, so we looking at 500Ah.
Now you using 6 000wh during the night, which you have to put back during 5 hours of light,
6 000/5h = 1200W
So you looking for at least 6 x 200W panels. This is now without any load during the day too.
1200W on a 24V system, gives you 50Amp, so you would need a charge controller of at least 50Amp or more.

If you looking at running 500W at 24/7, it changes the calculations a bit.
500w for 24h = 12 000wh.
To put that back in 5 hours = 12 000/5= 2400W
So that is 12 x 200W panels.
At 24V that is 100Amp controller required.

 

[spiderz]

My old man went solar, can run a whole house (think 4 bedroom plus granny flat) on batteries in the evening, the charge controller is a fancy aussie one, the inverter is a fancy European one, the deep cycle batteries (bank of 24 enormous things), and a few rows of pv panels (grouped into 3 clusters) from China.
The geyser is solar with very very low heat loss and gas backup.
The total cost was about R130k, when the dollar was about R7, for the solar conversion which he did himself except connection to the mains. Pretty much everything was imported.

Does he still have the links from where he imported all the stuff and pricing?

 

[supersunbird]

@supersunbird.

Right, so 500W for 12 hours = 6 000wh

Lets say you going 24V DC.
So 6 000/24 = 250Ah.
Now you can never draw 250Ah from a 250Ah battery, as they will not last long, so you need to double capacity to make sure your battries would last, so we looking at 500Ah.
Now you using 6 000wh during the night, which you have to put back during 5 hours of light,
6 000/5h = 1200W
So you looking for at least 6 x 200W panels. This is now without any load during the day too.
1200W on a 24V system, gives you 50Amp, so you would need a charge controller of at least 50Amp or more.

If you looking at running 500W at 24/7, it changes the calculations a bit.
500w for 24h = 12 000wh.
To put that back in 5 hours = 12 000/5= 2400W
So that is 12 x 200W panels.
At 24V that is 100Amp controller required.

Thanks a lot, now I can start looking at what to it will cost me. I was suspecting about 6 x 200w panels.

Would be worth it to go lights and security off grid. I hate looking at those houses that stay lit up during power outages lol. All other things like heating food and such can be done with gel stove and such.

 

[ElecEng]

Thanks a lot, now I can start looking at what to it will cost me. I was suspecting about 6 x 200w panels.

Would be worth it to go lights and security off grid. I hate looking at those houses that stay lit up during power outages lol. All other things like heating food and such can be done with gel stove and such.

This isn't right. A 200w panel will not produce 200w for 5h / day. If you want it off grid, you need to account for the cloudiest day in winter (when the sun is not at the optimal angle).

It gives you a rough idea of the system size, but you would probably have to double the number of panels.

 

[supersunbird]

This isn't right. A 200w panel will not produce 200w for 5h / day. If you want it off grid, you need to account for the cloudiest day in winter (when the sun is not at the optimal angle).

It gives you a rough idea of the system size, but you would probably have to double the number of panels.

500w is worst case, it will be more like 250w most of the night (the outside lighting), internally and externally all the bulbs on the lights circuits are CFL or LED.

 

[spiderz]

Would be worth it to go lights and security off grid. I hate looking at those houses that stay lit up during power outages lol. All other things like heating food and such can be done with gel stove and such.

Make the outside light movement lights. Only comes on if there is movement.

 

[supersunbird]

Make the outside light movement lights. Only comes on if there is movement.

I will as soon as someone makes half-eyelid bulkheads fittings (aesthetically please to me) with such