Safety and Legality of DIY Small 300 Watt Grid Tied Inverter

[natel]

So, I'm in California and I'm fairly new to solar and I'm wondering if I can create a very small diy grid tied inverter system with a couple of 120 or 150 watt panels. Are there any inverters now that are smart enough not to cause a danger to PGE or my electrical company in the case of a power outage? I believe that name for that feature is called an auto disconnect? Is that right? Are there any plug and play kits that are not terribly expensive?

[billvon]

So, I'm in California and I'm fairly new to solar and I'm wondering if I can create a very small diy grid tied inverter system with a couple of 120 or 150 watt panels. Are there any inverters now that are smart enough not to cause a danger to PGE or my electrical company in the case of a power outage?

Every grid tie inverter out there will disconnect when the grid goes down. This feature is called "anti-islanding."

Are there any plug and play kits that are not terribly expensive?

They're are, but there are no systems out there that are legal to just "plug in." They have to be installed into the structure to be legal, and have features like dedicated circuits, external lockable AC disconnects etc.

[natel]

So, there are not that I can simply connect the positive and negative terminal from the solar panel and plug it into an AC outlet and be done? It sure seems like there's a lot of these selling and a lot of people doing this, are there not?

Every grid tie inverter out there will disconnect when the grid goes down. This feature is called "anti-islanding."



They're are, but there are no systems out there that are legal to just "plug in." They have to be installed into the structure to be legal, and have features like dedicated circuits, external lockable AC disconnects etc.

[russ]

So, there are not that I can simply connect the positive and negative terminal from the solar panel and plug it into an AC outlet and be done? It sure seems like there's a lot of these selling and a lot of people doing this, are there not?

A lot of people (read hucksters) sell lots of strange 'stuff' - in the US you will not find even one of what you are talking about sold by a reputable company - not a single one. To be legal grid tie has connect to the main panel in an approved configuration - not to some plug in.

There are rather good reasons for this requirement!

[billvon]

So, there are not that I can simply connect the positive and negative terminal from the solar panel and plug it into an AC outlet and be done?

Not legally, no. Some people have installed "guerrilla" systems that work that way, but that's generally a bad idea unless you know exactly what you're doing.

[peakbagger]

Only legal way to install small systems is go with microinverters. The installations need to be permitted and depending on the jurisdiction most likely has to be signed off/installed by an electrician. Anyway else you personally are liable for any damage you do to your house or to any folks who might be injured. Your insurance doesnt cover it. Odds are the non rated GTI is going be very inefficinet built with poor qulaity components. If the utility catches it, they turn your power off and then it up to you to pursuade them to turn in on again after a few weeks.

Get yourself a battery and a charge controller and stay off the gird until you get serious.

[KRenn]

Not legally, no. Some people have installed "guerrilla" systems that work that way, but that's generally a bad idea unless you know exactly what you're doing.

There was a homeowner in Colorado that got caught doing just that and it seemed like everyone from the utility to the AHJ to the fire marshal lined up to slap him upside the head for it. Wouldn't recommend going "guerilla" on the grid.

[billvon]

There was a homeowner in Colorado that got caught doing just that and it seemed like everyone from the utility to the AHJ to the fire marshal lined up to slap him upside the head for it. Wouldn't recommend going "guerilla" on the grid.

Yep, city inspectors and fire departments really frown on it. But that's a political issue, not a safety one. The approval process itself does not add a layer of safety, it just ensures that the system meets NEC requirements. Two systems that are installed to the same standards are both as safe, even if one has approval and one doesn't. (The trick is, of course, installing it to the same standards.)

[russ]

a principle of the forum is that we totally do not recommend people go the "guerilla" route.

If someone wants advice for that type of thing they can go elsewhere.

[Sunking]

There was a homeowner in Colorado that got caught doing just that and it seemed like everyone from the utility to the AHJ to the fire marshal lined up to slap him upside the head for it. Wouldn't recommend going "guerilla" on the grid.

The AHJ and Fire Marshalls are going to get even toughter on solar installs because of the numerous house fires being reported.

Keep in mind the electrical codes are written by engineers, electricians, manufactures, Fire Departments, Municipal Building inspectors, OSHA, and Insurance companies. They have a vested interest in your security and their conspiracy. They all make and loose a lot of money over it.

[natel]

a big no no?

So, something like this is a big no no?

http://www.ebay.com/itm/500w-Grid-Tie-Inverter-for-solar-panel-wind-battery-pure-sina-wave-power-500w-/251077268735#ht_4797wt_1388

[billvon]

So, something like this is a big no no?

Wouldn't be a great idea, no. It might work (in that you might well be able to feed power back) but wouldn't be permittable. And if they don't follow basic anti-islanding design it would be very unsafe as well.

Also note that based on what they say in their ad they don't seem to have much of a grasp of basic electrical wiring. Quote: "In order to achieve higher power use requirements, this product can be stacked use，Such as：4pcs 1000W inverter stack use result is 4000w，And does not limit the number of inverter, Used as shown picture:" then a picture showing four inverters plugged into a power strip. 4 1000 watt inverters will blow any 15 or 20A circuit pretty much instantly, and 4 500 watt inverters will also blow a typical 15A circuit. (16.6 amps if they can really produce 500 watts.)

[natel]

asian

So, these are obviously coming from Asia and it seems that even sellers in the United States do not list these items with proper English. But, if you search completed listings on Ebay, there's a lot of these selling. So, it seems people are buying them and I assume they're using them in the U.S.

Wouldn't be a great idea, no. It might work (in that you might well be able to feed power back) but wouldn't be permittable. And if they don't follow basic anti-islanding design it would be very unsafe as well.

Also note that based on what they say in their ad they don't seem to have much of a grasp of basic electrical wiring. Quote: "In order to achieve higher power use requirements, this product can be stacked use，Such as：4pcs 1000W inverter stack use result is 4000w，And does not limit the number of inverter, Used as shown picture:" then a picture showing four inverters plugged into a power strip. 4 1000 watt inverters will blow any 15 or 20A circuit pretty much instantly, and 4 500 watt inverters will also blow a typical 15A circuit. (16.6 amps if they can really produce 500 watts.)

[russ]

Things like this are the reason the term 'flea bay' is commonly seen here - all too often you have hucksters selling junk to the public.

[natel]

yikes!

Here's somebody who had the guts to post a video about his system: http://www.youtube.com/watch?v=9Ztr5_EJjwI