Micro Grid Tie and Mechanical Electric Meters?

[mattc]

Hi All

I have 190W of solar panels and a 350w Micro Grid Tie Inverter (I know, its the poor mans on-grid PV system ). I noticed that my electric meter is an older style meter with mechanical numbers on it. It has no digital display but also no spinning wheel either so it's old but not that old. My question is, does anyone know how the grid tie will affect it once up and running? As I dont have net metering, would using the grid tie inverter slow the meter dials down or could it actually speed them up?

Matt

[peakbagger]

First for the obligatory comment (specific to the US as I am not sure where you are located), it sounds like its not a "poor mans system" its most likely is an illegal installation unless some company is currently offering a UL 1741 rated grid tie inverter at 350 Watts. If there is please let me know as I am looking for one, but all the 350 watt units I have seen are ebay specials glossed up with dubious claims and not rated for UL 1741.

That said, the majority of older meters do seem to run backwards when back fed but when utilities bought them in bulk I expect they could order them with a ratchet feature or even worse a feature to record generation as usage. Its pretty easy to test, turn off all the circuits on the breaker panel and run the grid tie, then watch the meter. When you fill out the application to get permission from the utility to install a grid tied unit, I expect they will install a new meter. Most utilities have fraud/maintenance software that tracks the power usage of a house over the long term, it flags when the usage changes and the normal response is to send out a tech with a new meter and install it. My utility has the meterreaders trained to keep an eye out for illegal installs. If they see an illegal hook up, expect that the meter will get pulled and a note will be left explaining that they wil not reconnect until the illegal installation is removed and permitted. They usually make the now powerless owner schedule a service tech back to pop the meter in and charge the owner a fee that will be well in excess of what one panel would supply.

In reality I would expect a 190 watt panel is at best just going to offset phamtom loads so the meter will never stop, just slow down a bit.

[mattc]

Thanks for the comprehensive reply on the legalities. I don't live in the US and am aware of the legal / insurance risks. I like the test idea though,I'll have a go at that. Even at the full 190 watts, I Might have to wait a while to see movement from the meter.

Cheers

[SunEagle]

Thanks for the comprehensive reply on the legalities. I don't live in the US and am aware of the legal / insurance risks. I like the test idea though,I'll have a go at that. Even at the full 190 watts, I Might have to wait a while to see movement from the meter.

Cheers

Even though you do not live in the US and there may be no laws against using your "grid tie" inverter, I would caution you not to use it.

Most if not all of the inverters that plug into a wall receptacle are not properly built with short circuit protection (fuses) and can cause electric shorts and fires.

[green]

First of all I must say that we do not condone the use of dangerous uncertified equipment around here. But if you won't heed the warnings and disconnect it, please do these two things. First make sure the unit is connected to a circuit that has nothing else running on it, a dedicated circuit, professional installers do this for a very good reason. Second do not install the unit inside or attached to the outside of your house.

Better yet just don't use it at all. Do you have children living in this house? Is a few cents worth of electricity worth risking their safety? Don't take offence, I had to ask myself these same questions. Needless to say, all my DIY panels are off grid and away from my buildings. The cheap GTI I bought is $60 I will never see again because I can't even sell it in good conscience to the next sucker. Codes and regulations are in place to protect not only you but the ones you love and the people who may need to come to your rescue.

Whatever you do please do it safely.
Green

[mattc]

It has a built in fuse and I'll have a seperate fuse between solar panels and inverter. The inverter does not power up until it detects grid ac power (to prevent electric shock to workers if the grid fails). I'm keeping the inverter well away from the house in a ventilated shed. The worst thing that could happen is I burn my shed down and burn my pride a little at the same time. No harm done to anyone else for the sake of a little green power.

[russ]

No harm done to anyone else for the sake of a little green power.

Wrong - very wrong and this is one of the many things wrong with the green concept. Too many greens consider the ends justify the means.

[mattc]

It's people that like to tinker with things in sheds that discover the new technologies that you are now using and then telling other people how to use. Then we have to pay some other middle man cashing in to have a license to say its 'ok to install' . Don't get me wrong, I appreciate the importance of safety regulations and certificates but really... a 350w inverter? Come on.

Sorry rant over!

[green]

I'm keeping the inverter well away from the house in a ventilated shed. The worst thing that could happen is I burn my shed down and burn my pride a little at the same time. No harm done to anyone else for the sake of a little green power.

No, there are worse things. That shed is connected to your house through the wiring. A dollar to a dime says that it is not on it's own circuit, probably just tapped into an existing circuit. Back feeding a circuit that is already close to it's limit can be very dangerous. The wires in your walls can overheat and cause a fire without tripping the breaker. Also back feeding a breaker that is not designed or rated for it is a bad idea also.

Then there is your homeowners insurance. If your insurer finds out you are illegally grid tied they can drop your coverage. That won't sit well with your mortgage holder. Plus if there is a fire in your house your claim may be denied even if it had nothing to do with your GTI.

I'm telling you it's not worth it. But you won't listen because making your own energy is addicting. Once you start, you want more, like a drug. You will probably keep adding to that shed circuit until it's overloaded and dangerous and to late.

I am one of those tinkerers you speak of. I have changed my focus to solar off grid and direct solar powering various things. I used to think about like you that everyone was just against me getting into solar on a budget, but.. the more I read and listened to those with the knowledge, I realized I didn't have all of the answers... I just needed to ask more questions. Keep an open mind and don't take offence when people try to help you.

Green

[FloridaSun]

It's people that like to tinker with things in sheds that discover the new technologies that you are now using and then telling other people how to use. Then we have to pay some other middle man cashing in to have a license to say its 'ok to install' . Don't get me wrong, I appreciate the importance of safety regulations and certificates but really... a 350w inverter? Come on.

Sorry rant over!

Sorry, rant not over..
For the sake of a little 'green power' you have already prepaid the middle man in purchasing your equipment which will not repay itself in many many years. That 'green power' will also take several years to negate the energy required to produce a panel, not to mention CC, inverter, wiring, etc.
Not too much 'green' about it. Tinker on but don't claim you are doing anything for the environment.

[Sunking]

Meters, even mechanical meters made after 1980 have a mechanism inside that prevent s them from running backwards. This was done to prevent fraud and theft of electricity. All you had to do was unplug the meter and put it back in upside down to make it run backwards. Mechanical meters today run forward regardless which way it is installed or which way power is flowing.

[mattc]

Ok fair enough, you're starting to sway me. It's all very disheartening though. Even with the feed in tarrif insentive, I cannot afford to cover my roof in solar panels and get the real deal GTI's installed. Is there any option for me at all?

I dont plan on adding more GTI's to my rig taking everything in to account. From what I can see, off grid makes little sense too what with the losses from batteries etc.

If there was ever an achillies heal with solar, its storage technologies.

Matt

[Sunking]

If there was ever an achillies heal with solar, its storage technologies.

That is certainly part of it but not the real achillies heel. That would be the government subsidies. If it were not for the subsidies there would be no solar period. As soon as subsidies are gone, so will be solar. It is just not fair that electric rate payers and tax payers have to foot the bill for someone else luxury.

[green]

Is there any option for me at all?

Research Solar Thermal Heating and Solar Hot Water. Much more bang for your buck in those areas. You can still find a use for your existing panels, just depends on what you want. Mine do various tasks including charging my children's electric Power Wheels vehicles. They are not really saving me any money but they sure are a conversation starter.

[mattc]

Yes, I also have a charge controller attached to 110ah battery and a little AC inverter for lots of things from mobile charging to tablets etc. At least my panels aren't going to complete waste

Back to the GTI for a moment? I may have found another flaw with my system which I really would like confirming? My house, like many has two circuits for sockets (usually upstairs/downstairs). Only mine is very strange in that its not split by upstairs/downstairs. Its split by two sides of the house! My GTI is plugged in to the side of the house which is not used by TV, PC, Router (which are the main 'sustained power' type appliances that are on most of the day).

Am I right in saying that the circuits are seperate and affect the meter individually? What I'm getting at is that if the GTI is connected to socket circuit 1 (that has little useage), and socket circuit 2 has high use by the TV etc... the GTI cannot offset any of the the power used on circuit 2? Therefore my meter will tick away faster not slower???

Matt