legionsolar out of San Jose figures out plug and play.

[Bigbillsd]

For a very long time I have been thinking of setting up a 300 watt solar panel and micro inverter and use it to supplement my always on house power usage. My only real concern was my power company states they will shut off our power if they detect watts of power backfeeding the grid without first going thru the netmetering process.

This week I found legionsolar.com and they are selling what I was thinking about making and solved the potential backfeed issue with a power regulator that uses clamp on cores to sense power use from the grid and will automatically shut down any or all their micro-inverters so they will only produce power if they aren't going to backfeed the grid. They sell them in 300 watt increments. After talking to one of their engineers he explained that the regulator shuts off individual inverters to prevent backfeeding. Example you install 900 watts because that is what is always being drawn during sunny hours at your house. But for some reason, say a breaker trips and some of your stuff stops drawing power and now you are using 620 watts, the regulator will shut off just one of the inverters so you cannot produce more than 600 watts. (it will leave 2 providing power) Kind of a sledgehammer approach but it should get the job done. I was hoping it could just tell the inverters to lower their output but that may not be technically possible... .

Its a pretty interesting way to do it. The inverters and regulator talk via WiFi (not your WiFi) The micro-inverters only turn on, if the regulator is sensing enough power is being consumed. The base kit is $599 for 300 watts then you can add extension packs of 300 watts each later up to whatever you require. I am considering pulling the trigger on one of the base units just to see if it really works. My homes constant draw is a little over 600 watts, so if the 300 w kit works out I my get one of the extension units. They suggest you take your always on power draw and multiply that by 1.4 which seems reasonable to me.based on panels only rarely produce the power they are rated for unless you get perfect conditions.. -Bill

PS. I asked about UL listings. They are not there yet.

[SunEagle]

Discovering a pv system that back feeds into the grid is only one way a POCO can tell if a system is installed. Another way is that your kWh usage goes down or no longer fits previous usage charts. They then come out to investigate your power connection. If they find a pv system then you are screwed without a Contract.

I would at least investigate what a Contract with your POCO costs you and weigh that to the cost of those devices you are looking at which if not UL listed can get you into more trouble with your local code inforcer.

[J.P.M.]

If you are in the U.S., not having UL cert. is a deal killer.
- If grid tied, you're screwed if discovered by the POCO. The chances of discovery are usually rather high.
- In the event of a fire or other damage traceable to the non UL equipment, your insurance co. will probably disallow any claim.

Why not just grid tie ? That can usually be done for < $600.

Your constant draw of 600 W seems a bit high. You sure about that ? Is this for a residence ?

Add: If your "constant" draw is 600 W, a 300 W system will never cause any feedback to the grid.

[bcroe]

If you have vampire loading of 600W (everything turned off), your first step should be
to track them down and minimize them. I managed to eliminate 80% of my 300W vampire
loads over a couple years.

After that you could look for loads that could be run directly by the sun. HVAC equipment
is available with this capability. Hang clothes on the line. Bruce Roe

[Ampster]

Discovering a pv system that back feeds into the grid is only one way a POCO can tell if a system is installed. Another way is that your kWh usage goes down or no longer fits previous usage charts. They then come out to investigate your power connection. If they find a pv system then you are screwed without a Contract.

I investigated that pretty thoroughly at least in California and found no regulations that said I could not generate my own power. To be clear, I determined that i must have a building permit for any electrical device, circuits and generating equipment. That generating equipment needs to be UL approved and cannot be configured to back feed the grid. The local building officials in the County of Sonoma and the City of Hermosa Beach, California confirmed this. At least in California and what little I know of Hawaii the jurisdiction of the Power Compny ends at the meter.

[Ampster]

.....
- If grid tied, you're screwed if discovered by the POCO. The chances of discovery are usually rather high.

I assume you are talking about someone with a grid connection who has significantly dropped his consumption of energy from the power company. Do you have any data to back up that statement?

[SunEagle]

I assume you are talking about someone with a grid connection who has significantly dropped his consumption of energy from the power company. Do you have any data to back up that statement?

Based on what my friends at a couple of local Florida POCO's, they have a computer system that will alert their staff if the consumption is lower over a period of time then it was for previous months. This alert is there to help them understand what has changed. It is usually followed up with a site visit to check the grid connection systems. If they find anything out of the ordinary they will continue to investigate.

The computer check was put into place when people started to use much more electricity then they had in the past. The reason was usually a "grow house" that consumed a lot more kWh then the customer use to. It also would find if a neighbor was tapping into an outlet through an extension.

It all comes down to meters now being able to record and track unusual usage.

I can only say anyone that tries to install a pv system without a contract with their POCO is taking a chance.

[SunEagle]

I investigated that pretty thoroughly at least in California and found no regulations that said I could not generate my own power. To be clear, I determined that i must have a building permit for any electrical device, circuits and generating equipment. That generating equipment needs to be UL approved and cannot be configured to back feed the grid. The local building officials in the County of Sonoma and the City of Hermosa Beach, California confirmed this. At least in California and what little I know of Hawaii the jurisdiction of the Power Compny ends at the meter.

If the OP wants to have a pv system but not back feed then they need to get an inverter that will not do that.

[J.P.M.]

I assume you are talking about someone with a grid connection who has significantly dropped his consumption of energy from the power company. Do you have any data to back up that statement?

That may be one way.

Another may be when a smart meter reveals power flowing from a residence and there is no net metering agreement in place.

As for data, I rely on common sense and some knowledge of how power grids operate. Try educating yourself in such things.

[Ampster]

If the OP wants to have a pv system but not back feed then they need to get an inverter that will not do that.

He is apparently in California and there is no statute that limits power generation behind the meter to models of inverter that cannot export. The only requirement is that IF you export you must get a Permission To Operate from your utility to sell back power. For example most Hybrid inverters have several modes some of which export and some of which are Grid Zero modes. In Grid Zero mode the inverter syncs to the grid for frequency but modulates battery and or solar output so that no power back feeds the grid. The ones I am referring to are all UL 1741 compliant.

The equipment the Original Poster is talking about is not UL compliant in any way and I would not recommend using that kind of equipment.

[Ampster]

That may be one way.

I am not suggesting any particular way. I wanted to make sure I understood your sentence the way you intended when consumption drops. How can the power company distinguish between load decline from self generation or from a semi vacant home?

As for data, I rely on common sense and some knowledge of how power grids operate. Try educating yourself in such things.

As I posted above I have spent considerable time informing myself about this particular issue of the right to generate power behind the meter without needing permission from the utility. I have researched the issue in legal journals and read the Civil Code. I have also asked on several occasions on this and other forums and no one has shown me any code section or utility tarrif that contradicts my belief. I continue to hear statements like, "If grid tied you're screwed if discovered by the POCO" which are unsubstantiated.

I ran my hybrid inverter to power my household while PG & E linemen were repairing the grid connection in my neigborhood. They were working in the vault, twenty feet from my inverter and we discussed my system. I never got screwed by them during our thirty minute intercourse.
I respectfully ask again, do you have any data or a reference to the Civil Code that supports your claim that behind the meter generating (inverting to be specific) equipment that is UL approved needs the permission of an investor Owned Utility in California?

[Bigbillsd]

I am not concerned that the poco could find out. There is nothing they can do to me unless I back-feed the grid. Which is highly unlikely. The non UL listed stuff does concern me. But I could cobble all this totgether with UL listed equipment except the solar regulator that is unique to this company. Hard to imagine the panels and inverters aren't UL listed already though. I would guess the only part not UL listed is the regulator. And its a 5v device with a wall wart. .

As for my 600 w constant draw, I know what it is. A few servers, many POE powered cameras on the perimeter, routers, switches, ATSC signal Ethernet recorders, VOIP system etc. And other things that run more often than I think they should like the freezer and fridge. Both are old, coils cleaned but still need to be replaced with energy star appliances.

[Mike90250]

You are looking to spend a fair amount of money and labor, to install a quasi-legit system that can only offset your consumption for a 6 hour window of a 24 hr day.

Why not at least explore going all out, and installing a large enough system that can actually unwind your meter, or sell back at the high price portion of the day. Get it blessed by the building depart & the electric company, and actually realize a sizeable savings over 10 years. And unless you have shade issues, you should not need to use microinverters.

[Ampster]

Based on what my friends at a couple of local Florida POCO's, they have a computer system that will alert their staff if the consumption is lower over a period of time then it was for previous months. This alert is there to help them understand what has changed. It is usually followed up with a site visit to check the grid connection systems. If they find anything out of the ordinary they will continue to investigate.

The computer check was put into place when people started to use much more electricity then they had in the past. The reason was usually a "grow house" that consumed a lot more kWh then the customer use to. It also would find if a neighbor was tapping into an outlet through an extension.

It all comes down to meters now being able to record and track unusual usage.

I can only say anyone that tries to install a pv system without a contract with their POCO is taking a chance.

No doubt those utilities do that. You are correct that anybody who installs solar is taking a chance but it is important to understand what that risk is. It is an economic risk not a regulatory risk as you have suggested.

Your example does not address the issue about whether the Original Poster or I can operate a "generating facility" behind the meter in California.

Maybe Florida is different but with the low rates there economics probably are the big driver that prevents people from even considering doing that. The only cases I have seen in California where the Investor Owned Utilities have done anything like your friends in Florida have done is in cases of battery installations funded by grants. In the case of Self Generation Incentive Program grants the agreement specifically prohibits selling power from batteries that have been charged from the grid or from solar. In those cases the expected output of the grantees existing solar is used as the standard for which that facility cannot sell more to the grid. That is a case of a contractual relationship pertaining to the terms of the grant and an existing PTO regarding selling to the grid.

I am still waiting for somebody to give me the Civil Code section or any other law in any other state that restricts the right of a homeowner to generate their own electricity. I do understand that Municipal Utilities may have the ability to legislate such restrictions but those cases may be rare.

[Ampster]

You are looking to spend a fair amount of money and labor, to install a quasi-legit system that can only offset your consumption for a 6 hour window of a 24 hr day.

Why not at least explore going all out, and installing a large enough system that can actually unwind your meter, or sell back at the high price portion of the day. Get it blessed by the building depart & the electric company, and actually realize a sizeable savings over 10 years. And unless you have shade issues, you should not need to use microinverters.

I think the long term view as Mike suggests is probably the best approach.