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Comment by jandrese | Hacker News Reader

> On the contrary, they are low voltage (12V), which makes them more dangerous (because you need higher amps to carry the same amount of energy). To make them safe, you can install inverters closer to the panel, to raise the voltage to 110 or 220, making them much much safer.

Lets check a random common panel.

https://www.solar-electric.com/rec-solar-rec400aa-pure-alpha...

Voc: 48.8 Volts

And the original post was talking about cheap installs, so you would string several together to put it on an inverter. You hit high voltages very quickly. Even just 4 panels and you're up to almost 200V at full sun. It's more typical to put 8-12 panels on a string. The voltages hit dangerous levels very quickly.

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Again, the dangerous part is the intensity, the amps. Look at your panel in the link, it's at more than 9 amps. If you put them in parallel, you will keep the low voltage, but quickly rise the amps, if you have 5 panels in parallel you are at 45 amps!! That can cause the fires, not the voltage.

You want to tie them in series first, to increase the voltage and keep the amps as low as possible. 110V or 220V are not dangerous voltages, that's why houses are wired at these higher volts. People all over the world handle cables carrying 220V with very few issues. If you wired the house at 12V-48V, some wire in the wall would catch on fire every-time you wanted to toast a slice of bread, lol.

Solar panels are wired in series.

You just can't admit being wrong, can you?

They are typically first wired in series to increase the voltage as early as possible, to make them safer. If you were to wire them in parallel you would keep a low voltage and increase the amperage, which would make their wires glow like Christmas lights.

That's the whole reason why they started selling micro-inverters that go on each panel: to increase the voltage and decrease amps before even leaving the panel area, to make them safer.

Look at a typical micro-inverter: input is up to 50 volts, 10 amps. Output is 240 volts, 1 amp. https://solartown.com/solar-products/enphase-iq8-microinvert...

For panels, the voltage is not dangerous part, the intensity is.

You aren't going to achieve your goal of ultra-cheap panels everywhere if you're sticking expensive microinverters on each one. It's weird that you say "I'm wrong" then laboriously explain to me how I was right. The panels are wired in series. The voltages are up in the 100s, which will easily overcome the resistance of your skin.

If they were actually 12v they would be safer. You could handle them with dry skin. It's the same reason people aren't electrocuted while working on cars. The danger would be starting fires as you noted.

Anyway, in the real world when you have panels wired in series you typically need to shield the connection wires in conduit because both the voltage and amperage reach dangerous levels and you can start fires or kill people if they try to handle the wire, and you can't easily turn them off. This is part of the expense of installing solar panels that you can't really avoid. You will always need someone who knows what they are doing to handle the electrical part or you will kill people.

It's also DC - arcs won't self extinguish like AC will. Modern charger/inverters are trending towards nominal 1kv voltages for the individual panel strings too which is pretty impressive. 20amps at 1kv is 20kw!

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