Mini grid tie system without net metering

[Deren]

As of yesterday, my state has the distinction of being the first in the US to end net metering completely. Our local utility gets to charge us 40 cents per kWh, so I guess they had plenty of incentive to corrupt the PUC. Anyway, although I wasn't yet prepared to spend the money for a large PV system, I was hoping to at some point but that's pretty much off the table for quite a while longer. And before you say go off grid with batteries, that would require an investment I am not currently able to make.

Soooo....now I'm thinking of just installing a small DIY system in the immediate short term to offset some electrical usage during the day. Something along the lines of a few panels (maybe DIY panels if I can find the time, just for fun) and one of those cheap Chinese inverters from amazon.

Questions:
1. If I plug one of these cheap inverters in to a 120v socket, the power is only going to one rail, right? Does that mean only things on circuits plugged in to that rail will receive the power? So let's say I generate 500watts, but I'm consuming power total power at 600watts and it happens to be 300 watts per rail, am I giving 200watts to the power company for free while I'm buying 300 watts from them? I assume with net metering this would average out, but with no net metering...
2. Is there anything else I should know about a little non-netmetering grid tie system? Everything I read about grid tie seems to assume net metering.

[solar pete]

As of yesterday, my state has the distinction of being the first in the US to end net metering completely. Our local utility gets to charge us 40 cents per kWh, so I guess they had plenty of incentive to corrupt the PUC. Anyway, although I wasn't yet prepared to spend the money for a large PV system, I was hoping to at some point but that's pretty much off the table for quite a while longer. And before you say go off grid with batteries, that would require an investment I am not currently able to make.

Soooo....now I'm thinking of just installing a small DIY system in the immediate short term to offset some electrical usage during the day. Something along the lines of a few panels (maybe DIY panels if I can find the time, just for fun) and one of those cheap Chinese inverters from amazon.

Questions:
1. If I plug one of these cheap inverters in to a 120v socket, the power is only going to one rail, right? Does that mean only things on circuits plugged in to that rail will receive the power? So let's say I generate 500watts, but I'm consuming power total power at 600watts and it happens to be 300 watts per rail, am I giving 200watts to the power company for free while I'm buying 300 watts from them? I assume with net metering this would average out, but with no net metering...
2. Is there anything else I should know about a little non-netmetering grid tie system? Everything I read about grid tie seems to assume net metering.

Hi Deren and welcome to Solar Panel Talk. Now I dont mean to burst your bubble but someone has to, this question has come up before and it seems those cheap crappy chinese amazon inverters are actually illegal to use, sorry but thats how it is.

The first thing you need to do is contact the city and local poco as even though there may be no more net metering there will still be rules and regulations if you want to connect to their grid. So please dont buy anything until you have made some calls and worked out what you can and cant do, cheers.

[lkruper]

Hi Deren and welcome to Solar Panel Talk. Now I dont mean to burst your bubble but someone has to, this question has come up before and it seems those cheap crappy chinese amazon inverters are actually illegal to use, sorry but thats how it is.

The first thing you need to do is contact the city and local poco as even though there may be no more net metering there will still be rules and regulations if you want to connect to their grid. So please dont buy anything until you have made some calls and worked out what you can and cant do, cheers.

Are they legal in China?

[Wy_White_Wolf]

Deren,

1. What's your location? The setups that plug directly into the wall are illegal in many places. We can not advise on the use of them in those locations.

2. Depending on what type of meter is on the house you could end up paying the power company for any power you send back to the grid. Many meters are non-directional and add to the used power no matter what direction it flows through the meter.

WWW

[SunEagle]

As of yesterday, my state has the distinction of being the first in the US to end net metering completely. Our local utility gets to charge us 40 cents per kWh, so I guess they had plenty of incentive to corrupt the PUC. Anyway, although I wasn't yet prepared to spend the money for a large PV system, I was hoping to at some point but that's pretty much off the table for quite a while longer. And before you say go off grid with batteries, that would require an investment I am not currently able to make.

Soooo....now I'm thinking of just installing a small DIY system in the immediate short term to offset some electrical usage during the day. Something along the lines of a few panels (maybe DIY panels if I can find the time, just for fun) and one of those cheap Chinese inverters from amazon.

Questions:
1. If I plug one of these cheap inverters in to a 120v socket, the power is only going to one rail, right? Does that mean only things on circuits plugged in to that rail will receive the power? So let's say I generate 500watts, but I'm consuming power total power at 600watts and it happens to be 300 watts per rail, am I giving 200watts to the power company for free while I'm buying 300 watts from them? I assume with net metering this would average out, but with no net metering...
2. Is there anything else I should know about a little non-netmetering grid tie system? Everything I read about grid tie seems to assume net metering.

Deren

To address your first question, those cheap plug in inverters are first dangerous and second not UL Listed which means they are not legal to use in the US. Also if you do generate power while connected to the grid without an agreement with your POCO you actually may be charged for whatever power you do generate and do not consume.

To address your second question, actually you can install a legal "grid tie" system if you meet your POCO and AHJ requirements without having a net-metering agreement. Net Metering just means the POCO has to pay you for any power you generate. Even without it you will still be able to reduce your bill by not needing to purchase all of the power from the POCO because you generate some yourself. All that means is it will take longer to pay back the installed cost of your pv system. It does not mean you can't install a grid tie system with the POCO's blessing.

[jflorey2]

1. If I plug one of these cheap inverters in to a 120v socket, the power is only going to one rail, right? Does that mean only things on circuits plugged in to that rail will receive the power? So let's say I generate 500watts, but I'm consuming power total power at 600watts and it happens to be 300 watts per rail, am I giving 200watts to the power company for free while I'm buying 300 watts from them?

No. The meter measures power total, not power per leg. However, you should be aware that some meters will work OK, some meters will give you an error and/or report to the POCO that you are trying to backfeed power without an agreement, and some meters will increment no matter which way power flows. That means if you use 10kwhr in a day, and generate 8kwhr, you could get billed for 18 kwhr a day.

2. Is there anything else I should know about a little non-netmetering grid tie system? Everything I read about grid tie seems to assume net metering.

Two most important things are to 1) get it approved and 2) don't use a plug-in grid tie inverter.