Is this credible?

bgarrett

I am 58 years old and have read Popular Mechanics all my life (on an occasional basis)
I have NEVER found Popular Mechanics to have believeable stories.
Whats the experts opinion on this article?

http://www.popularmechanics.com/home_journal/home_improvement/4317039.html

mike95490

Re: Is this credible?

No.

It likely exists, but I suspect there will be problems with it. The micro-inverters have a pretty harsh environment to live in, and then you have the building inspectors and electric company to contend with too. They can barely grasp the basic Grid-Tie concept, let alone a homeowner doing it all. And you still have to run conduit to the service panel, and install breakers. And figure out which panel is the dead one in 14 months. i would not hold my breath, remember the $2 watt panels promised 15 years ago?



excerpt:
the firm Andalay Solar debuted its new AC panel, which eliminates the need for elaborate DC wiring and large, system-wide power inverters by building micro-inverters into each individual panel. For buyers willing to dip a toe in solar, the panels can be installed one at a time. For installers, the built-in racking, wiring and grounding allows a full 3-kilowatt system of about 20 panels to be installed by a two-man crew in less than a day. Andalay Solar CEO Barry Cinnamon expects such developments to lead to plug-and-play panels on U.S. home-store shelves within a few years.

Roderick

Re: Is this credible?

Yes, Andalay. The idea is to have less steps in the installation, and I think these panels are designed to be rackless, too.

On the financial boards, I've heard buzz about having these panels in stock at Home Depot, in states where Akeena, the parent company, does not have a presence. The target would be professional installers, though, not DIY'ers.

The panels are still expensive, so I don't think there would be a rush for people to self-install.

With a microinverter right on the panel, this setup would be easy to [illegally] plug in, so there could be some "cowboy" installations encouraged by it. But again, the price will limit those, too.

Windsun

Re: Is this credible?

Those are basically standard panels (forgot which brand) with an OEM version of the Enphase inverter already attached. Going by the price that I saw, much cheaper to buy them seperately.

bgarrett

Re: Is this credible?

You guys know a lot more than I do.
1. The articles headline asks, "Is the Cost-Effective DIY Solar Panel Within Reach?"
2. Next it mentions "getting rid of the dangerous DC wiring "
3. Then "cost-effective, truly DIY solar panel"
4. "working with live 400- or 600-volt wiring"
5. "Somebody who doesn't know what they're doing can get killed. We're not talking about a little shock from a low-voltage appliance." Wright is referring to the live high-voltage DC wire essential to a traditional inverter setup"

Is ANY of this true?
DC is dangerous?
400 volts???
get killed by solar panels???

BB.

Re: Is this credible?

Marketing hype to a degree--with some truth too...

Roughly, >10 milliamps (0.01 amps) can be fatal-- if applied correctly and the current goes through the heart.

So--it takes a certain amount of voltage to push that current through your body--less than 24 VDC, not likely to kill. More than 60 VDC, then can push enough current to kill (wet skin, salty water, etc.).

Also, DC current is actually more difficult for switches and fuse to "break". DC sustains arcs better than AC current (DC arc welders are very common).

And, DC current can cause your hands to "grasp" the wire/metal component and make it very difficult to let go. AC current tends not to cause a grasping reflex.

Yes, solar panels can generate high voltage--just connect the panels in series. My ~32 Vmp panels are wired 10 in series (two strings in parallel) for ~320 volts DC (at 10 amps) to power my Grid Tie Inverter.

And, maximum current available affects the possibility for fire.

Is it easier to wire an AC system vs DC? Not really--they both have very similar requirements to meet code.

In the end--240 VAC or 200-600 VDC are going to be (roughly) equally dangerous. Do something wrong, and get knocked off the roof, electrocuted, or start a fire.

-Bill

bgarrett

Re: Is this credible?

Am I going to have 200-600 VDC in my solar system?
I have been planning for
24 volts dc.

RandomJoe

Re: Is this credible?

If you set up an off-grid or battery-backed grid-tie system, then no you don't need that high of a DC voltage. If you are planning to do a straight grid-tie system with no batteries, then yes most (all?) of them run the high voltage DC.

A battery-based system can get higher DC voltages as well, if you run MPPT. But the limit for those is usually 150V max. I have a 12V system (lots of ham radio gear that runs 12V native) but run in the neighborhood of 75V DC (all the panels in series) to the charge controller, so I can use smaller wire.

bgarrett

Re: Is this credible?

I will be offgrid
and will install the sytem myself.
I am familiar with the NEC

mike95490

Re: Is this credible?

Here's a link to a blog entry, that is well fleshed out, about the system build:
http://thekrusechronicles.blogspot.com/2009/06/solar-power-long-post.html

I'm very much in favor of going right to a 48V system, of all series batteries, than to have parallel 24v banks.

bgarrett

Re: Is this credible?

Thank you for the link.
Good reading

niel

Re: Is this credible?

i'm not too sure of your big fears being stoked as really being founded with high voltages unless you fear utility 120/240vac now too and would want to get rid of it too.

bgarrett

Re: Is this credible?

niel wrote: »

i'm not too sure of your big fears being stoked as really being founded with high voltages unless you fear utility 120/240vac now too and would want to get rid of it too.

huh? Are you talking to me?
I have respect but no fear of hi voltage at all.
I started replacing duplex receptacles hot when I was 21 years old.

bgarrett

Re: Is this credible?

My original question was,
Is this article credible when they are suggesting that solar systems have 'dangerous' 400 volts?

niel

Re: Is this credible?

ok and sorry if i'm misreading you, but it seemed like you had a bit of a fear factor in your line of questioning.