Solar help

[Domeguy]

Here are the numbers I came up with. The column on the left is for one freezer, and 2 freezers on the right.
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Approx $4876 for 1 freezer. Approx $9460 for 2 freezers. This does not include any roof racks, wiring, electrical panels, fuses, shut off switches, ect.
These figures are from one store only. You would need to check around to find the best prices.

[jamesneuen]

What size freezer did you get the numbers from? Those are kind of discouraging numbers for just a few freezers. lol. I wanted to have my entire house running on solar.

[helomech]

Thanks Domeguy.

[Domeguy]

What size freezer did you get the numbers from? Those are kind of discouraging numbers for just a few freezers. lol. I wanted to have my entire house running on solar.

Part of the high cost is the inefficiency problem. In a entire house, you can spread it out over a wider range. Although the total cost for the entire home is high, it won't be exponentially as high as this is. I hope that makes sense.

[jamesneuen]

Kind of. But I'm no electrician. I know solar panels themselves aren't very efficient but that's about it.

[Domeguy]

With DC power, You loose a percentage of the efficiency at the panels, at the inverter, the battery's, the wiring, all along the system. This is why we as a nation use AC power. During the power battles that started between Thomas Edison and Nicholas Tesla, Edison's DC power had to have a power station booster every couple of miles to keep up the voltage, where as Teslas AC system had very little power loss. Edison tried to show how dangerous the AC power is by publicly electrocuting large animals, even electrocuting an elephant to try to scare the public into using his system, but he ultimately lost and Tesla built his first AC electrical grid around Niagra Falls, NY.

[jamesneuen]

So by that reasoning you should station your panels and battery bank as close together as possible, with the inverter pretty much wired directly to the battery by the shortest means possible? Then if you wired the panels in-line with each other they would only have an additional foot or two instead of traveling the entire system?

I think I understand what you mean about the losses but would increasing the diameter of the DC wire reduce the resistance and make it more efficient or would that only work to a certain point?

[Domeguy]

Yes...and no. You would want the system components close to each other, Within reason. The panels are only X % efficient, no matter where there are placed, as also is the inverter. Battery's are also X% efficient! and together! these three things will bring the entire system to maybe 85-90% efficient, which is not to bad these days as it used to be a lot worse. The wiring however is a different matter. You would want the components as close together within reason, and as close to the power panel as possible. This is because you have a choice in the voltage drop in the wiring, just as you do not in the rest of the system. You can keep the wiring voltage drop down to 2-3 % by choosing the proper wiring size (or gauge), the length of the wiring run, and how much current you have flowing in the wire.
Your question and answer about wire size is correct. Choosing a wire to small will drop the current flow and cause the wire to overheat, which could then catch fire. But on the other hand, choosing a wire to big will also cause voltage drop just because it is too big, and would just cost you more money. The key to this delicate dance is " within reason". If you have to have the panels 300 feet away from the house you are trying to power, than they will have to be 300 feet away. Just do the math and choose the correct wire and realize there will be voltage loss, and suck it up like a big boy. But at the same time, connecting everything as close as possible would just cause the instillation to be a nightmare. The panels need to be outside, and USUALLY, the rest of the components should be inside away from the weather. So it's ok to separate them with a length of wire or cable WITHIN REASON. Also most people would not want to see the components of the system in their living room, even if this would be the most efficient wiring run. Most people would want to place the components in their garage, then run the wiring to the electric panel.

[jamesneuen]

Wow, I apparently need to take some electrical classes. Know of any free online classes?

I know there is a balance of voltage and amps to choose a correct wire size, so in a 12 volt base system what is the amperage based off of? And for any decent size current that would have to be a big wire till it is converted to AC. Or does the amperage and volts only work for AC?

[Domeguy]

Wow, I apparently need to take some electrical classes. Know of any free online classes?

I know there is a balance of voltage and amps to choose a correct wire size, so in a 12 volt base system what is the amperage based off of? And for any decent size current that would have to be a big wire till it is converted to AC. Or does the amperage and volts only work for AC?

I'm not sure of your question, but if you are asking where does the total amperage come from, it comes from the total solar panels and how they are hooked up, ie, in series or in parallel. Wired in series, the voltage goes up, but the amperage stays the same. In parallel, the amperage goes up but the voltage stays the same...maybe these pictures will help.
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