diy solar

diy solar

Impress your friends by using correct units and abbreviations

In all seriousness though, for proper terminology:

I have a 3Kw 24v inverter
It has 1800w of panels attached to it
I have 400w of panels on a parallel SCC
The batterie banks hold 5.7Kwh each (currently 1 bank, will be adding in the future)

What size system do I have?
11/64 of a cubit. Expect it to produce about 20 cords over a lustre.
 
More about wires:

THHN stands for Thermoplastic High Heat-resistant Nylon-coated.
THWN stands for Thermoplastic Heat and Water-resistant Nylon-coated.
XHHW stands for XLPE (which itself is an abbreviation for cross(X)-linked polyethylene) High Heat-resistant Water-resistant

You might come up with nomenclatures like: 20/7, 10/7, 8/7
First Number is the AWG gauge of the wire and the second number is the number of conductors.
Below, 8AWG is 8/7
1AWG would be 1/19.
This makes sense if you are in a hardware store, looking at a box labeled "3/7" and wondered what size is that spool...

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Yeah, as an engineer the mis-use of abbreviations and multipliers does grate somewhat (I even find it in supposedly "professional" equipment documentation!), although usually it's interpretable.

India opening a 100mW solar farm - Yeah, I get that, I have one on my calculator.
A 10KW heater - OK although I'm not sure what Kelvin-Watts are useful for.

Then along come the power-bank makers and specify capacity in mAh 'coz it gives a nice big number. Someone then asks "how big should a 33,000MAh power bank be?" - The size of a large building perhaps.
As a mechanical engineer I try not to be too critical, the rule of the land seems to be "The engine was doing X RPM's" when what you really just wrong is "revolutionS per minuteS". I'm sure I'm guilty of Lifepo4 and KW typos, as long as its interpreted in the correct setting you just let it go. Everyone is strong in their own field.
 
Someone then asks "how big should a 33,000MAh power bank be?" - The size of a large building perhaps.
especially when the voltage of the bank isn’t specified…

Imagine a 33,000MAh 400V bank… good LORD that would be huge…
My calculator doesn’t go that high…
 
Takes me back to the first lesson of Physics O-Level (UK education)
That whole first lesson and homework was listng/learning Si units!

It's locked in my memory as not the most exciting introduction to an amazingly diverse subject.

Doesn't mean I get them right of course - 15 years old was a long time ago :)
 
CME: Coronal Mass Ejection

ICME: Interplanetary Coronal Mass Ejection

CME is a Sun Fart. ICME is a Sun Fart that reaches Earth. More appropriate definitions will influence edits of this post. ?


Some folks are forecasting more of these over the next few years.
Maybe we should consider preparing for these in our solar systems, maybe not. That is a discussion for another thread.
I believe you can purchase emp shields and whole home surge protectors. I may be wrong may be correct
 
A - amps, a unit of current. Named after André-Marie Ampère.
V - volts, a unit of voltage. Named after Alessandro Volta.
W - watts, a unit of power. Named after James Watt.
Ω - ohms, a unit of resistance. Named after Georg Ohm.
h - hours
k - kilo (SI prefix for 1000)
K - Kelvin, a unit of temperature. Named after William Thomson, 1st Baron Kelvin. Not really relevant in solar discussions.
m - milli (SI prefix for 1/1000)
M - mega (SI prefix for 1000000)

Current is measured in amps - A
A battery's voltage is measured in volts - V
A battery's current capacity is measured in amp hours - Ah
Shouldn't "V - volts, a unit of voltage.", be a unit of Electromotive force? And "A battery's voltage is measured...", be, A battery's EMF is measured in volts - V?

My apprenticeship wasn't that long ago, but much smarter people seems to dwell here.

Also, kVAR hasn't been covered yet. Almost got there when comparing watts and voltamps.

It's what we refer to capacitors as, when trying to change the PF (power factor not pico farads) on the primary distribution lines (substation to homes). I'd guess that is because they are designed and built for a frequency of 60hz and their effect is known?

Hopefully this impresses friends and doesn't make enemies :-D
 
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