Comment by roughly | Hacker News Reader

Comment by roughly | Hacker News Reader

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> The currents and voltages involved are going to make that a non-starter. Do you really want random people messing with those?

As part of our daily lives, a great many of us climb into a steel box powered by explosions and packing a 20 gallon container of flammable liquids (and increasingly several hundred pounds of also flammable batteries containing more electricity than an average family uses in a week) and then pilot that box at 80Mph down a strip of concrete packed with other large high-speed objects containing flammable liquids. Occasionally, we run low on flammable liquids in our high-speed metal box and get to refill the flammable liquid container ourselves at a flammable liquids depot, which contains upwards of 40,000 gallons of the flammable liquid delivered by other larger high-speed metal boxes which also share the same strip of concrete with us.

So: I'd expect some product safety iteration here before we get to the "roll out your own solar panels", but no, I don't consider that a non-starter.

But you can see fuel. You can't see currents and it's not trivially visible which things you can touch at all, which things you can touch at the same time, which protection to wear, how to deal with the potentially fatal flashing arcs, ...

PV installations on roofs typically have around 10-20kW peak output.

Let's go with 10kW. That's around 25 panels, each outputting 30V with something like 13A. Small installations are typically single-stringed, so you end up with a voltage of 25*30V=750V with 13A DC. That's pretty likely to kill you within milliseconds if you mess up.

There's a reason that stuff tends to be handled by professionals. It's a ridiculous (and pointless) risk if you aren't well educated about it and have some experience.

You could probably make a system sockets that communicate with each other before exchanging any serious power. You could digitally sign cables, and add shielding to make them detect cuts..

I'm not saying it's a future we should want :)

But isn't that kind of how super chargers work?

Of course, until all our grid hook ups are smart, we'll probably need electricians at some point.

Enphase systems work as you describe. Each panel has its own AC inverter, and they from a mesh network and run sanity checks for shorts, etc. before exporting power.

There are lots of boxes in our house that do 16 amps at 120V. Some do 240V, and some do higher than that, and some of those are next to sinks or in high-humidity environments. The voltages and currents for solar panels (especially if you use 240V microinverters) don't seem like a non-starter to me.

That's AC. The panels are DC. That makes a big difference.

That said, the point of "do it yourself" is that you'd nake it less dangerous for ordinarily folk. So the risk of shocks would come down.

What would concern me more is long-term fire risk. If not installed correctly, with the right spec parts etc, proper grounding etc, there's a significant risk of fire. Not immediately perhaps, but a couple years down the road.

Again DIY kits would need to be designed with this in mind.

> That's AC. The panels are DC. That makes a big difference

What's the qualitative difference between 16 amps at 120V and PH v DC? Either is enough to kill a person if mishandled, and yet Home Depot sells breaker boxes over the counter.

So don't single string the DIY version into an uncontrolled danger wire. There's several ways to accomplish that.

750 volts will not kill you in single-digit milliseconds, but rather hundreds of milliseconds (or not at all), and it's probably worth it to run the extra wire to not be single-stringed

To be fair, it didn’t start that way and there are decades of design, legislation and safety regulations around all this, along with infrastructure for licensing/certifying capabilities, tracking and policing capabilities and mistakes over time, insurance, yada yada.

It’s not like that stuff springs up overnight!

the safety of these steel boxes were bought with blood over a hundred years.

and the end user doesn't just cut as much as they need and nail it down - the things are practically disposable appliances at this point.

Always worth pointing out the liquid is not only flammable, but also toxic.

And using the metal box creates toxic fumes that we inhale, which are deadly to every living thing on it.

You need a license, and usually some sort of training, in order to operate one.

And you know how much mockery Oregon and New Jersey get, for believing gasoline is so heinously dangerous as to require trained dispenser operators? Meanwhile the rest of us just pump it into our own cars like adults.

It's funny to look at electricity from the same perspective.

It has nothing to do with safety. It's pure protectionism. The point is to keep small gas stations competitive by imposing labor costs on larger gas stations.

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