Inverter "no injection"

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julianmh

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Hi All from south Spain.

I have beingalready readingyou fora couple of months, finally decided to participate.
At the moment I am stillworking on my powerwall (still charging-checking batteries)

Here in Spain legislation for solar energy it is quite restrictive, we can't transfer energy to the grid (no injection)

The plan is get around 10kw/h power wall, 20 200w panels,6000w 230v 50Hz inverter, charger and a unit to control that I don't send any energy to the exterior.

Do you have this kind of (no injection to the grip) restrictions in your countries?
how do you work with this?

Thank you for your feedback and hope can help at a point
 
Basically you want a standard inverter. With that, you need to have everything that runs off that inverter be in its own circuit box/panel. That is, if you want to use grid and battery at the same time.
If you are going to use one or the other at any given time, then you can install a Transfer switch that would allow you to use mains when battery voltages are too low or when the cells are being charged during off-peak hours; and then switch back to battery power when cells are charged or on-peak hours. Either method would work.

In the US, at least in Florida, they predominately installed grid-tie systems (grid-tie is what you call injection). However, battery storage is normally not installed at the time. So solar feeds power to the house and excess goes to the grid and the home owner "supposedly" gets a feedin tariff to offset the cost of used power.
Now, that doesn't mean that this is the only installations here. They do have battery installed systems, but they have the transfer switch installed. It is very similar to a transfer switch that is used for when a generator is installed into the house wiring (professionally).

Daromer (DIY Tech & Repairs on YouTube) has several videos on installing and configuring the transfer switches, both manual and automatic style.
 
There is generally 2 ways of doing this. The first one is not legal to do in many places...

You use a grid-tie or hybrid system where you set injection/grid transfer to 0. ie dont feed back. Thats not legal in many places at all. I can run it here but thats because im allowed to sell energy to the grid.

The second as Korishan talked about is an off grid system where you Tie your house after the inverter. Most those systems that are prebuilt can transfer between grid and battery/solar itself. If you get your self an inverter that only is inverter you need to add a control system and some kind of ATS. Beware of the systems that doesnt sync frequencys are prone to kill electronic stuff if you switch to fast.
 
Korishan said:
Basically you want a standard inverter. With that, you need to have everything that runs off that inverter be in its own circuit box/panel. That is, if you want to use grid and battery at the same time.
If you are going to use one or the other at any given time, then you can install a Transfer switch that would allow you to use mains when battery voltages are too low or when the cells are being charged during off-peak hours; and then switch back to battery power when cells are charged or on-peak hours. Either method would work.

In the US, at least in Florida, they predominately installed grid-tie systems (grid-tie is what you call injection). However, battery storage is normally not installed at the time. So solar feeds power to the house and excess goes to the grid and the home owner "supposedly" gets a feedin tariff to offset the cost of used power.
Now, that doesn't mean that this is the only installations here. They do have battery installed systems, but they have the transfer switch installed. It is very similar to a transfer switch that is used for when a generator is installed into the house wiring (professionally).

Daromer (DIY Tech & Repairs on YouTube) has several videos on installing and configuring the transfer switches, both manual and automatic style.
Click to expand...

Dear Korishan, thank you very much for your quick reply. I take note Gried-tie!

Here is a picture of what I have on batteries right now... still long way ahead :)

image_upxouc.jpg


I have seen some "dynamic power controllers" which modifies the MPPT (Maximum Power Point Tracker) of the inverters in order to regulate the PV generation according the energy consumption of the user:
If you requiere 3000w and you produce 1500w with solar: takes 1500w from solar and 1500w from grid
If you requiere 1000w and you produce 1500w with solar: takes 1000w from solar, and regulates the inverter to 1000w, not to put 500w on the grid.

Legislation and fines are really serious in Spain with this matter and you really want not to put power in the main grid.

I have seen a lot of kits on internet with this dynamic power controllers and very happy customers reviews with them, but don't know how to include the battery part on it.
Will have a look now at Daromer videos and come back with more doubts, Thanks again!
 
But all those systems are grid-tie... Are you allow to even add them up to the system? It doesnt matter if they dont send to grid or not. Are they even allowed and Legal in Spain? Most countries I know about they are not legal to use at all....
 
daromer said:
But all those systems are grid-tie... Are you allow to even add them up to the system? It doesnt matter if they dont send to grid or not. Are they even allowed and Legal in Spain? Most countries I know about they are not legal to use at all....
Click to expand...

Daromer thank you for your 2 replies.

As far as I know they are legal in Spain, this complies with RD900/2015 (Spanish law that mentions every seller)
You can have panels (up to 10Kw) with an inverter and use the grid at the same time.
The most important here is you don't send any power to the grid.Unless you register yourself as seller and pay a monthly fee (not worth at all)
What is not legal is to add a battery to the system. :mad: with this

I just seem one of your videos with you hybrid Mppt green inverter. Can you set on that inverter 0 power to the grid?
An Hybrid inverter with 0 grid set
 
So you can have solar panels but no batteries and your grid-tie inverter must be 1 way? That sucks.
 
The reason for the not having batteries with a grid-tie or hybrid inverter is that in the event the main transmission lines get damaged, you won't be feeding the line with power from the grid-tie unit. They don't make the units be intermediate as in, mains power comes in, go through the grid-tie, then to the breaker box/panel. If this was the case, then the grid-tie/hybrid unit could shut off power to the mains side. But, this is not the case.
This is the biggest issue with most places that allow you to connect solar (or other alternative energy) in line with the grid. They don't teach or required the installers to install an ATS on the line so that when mains is not present, it disconnects that side from the house, thereby 100% eliminating the possibility of a linesman from getting shocked/killed. I don't get it, honestly. This should be a required device in all structures that are mains tied and an alternative energy source is added to the system. It just makes plain sense.
 
Oderus420 said:
So you can have solar panels but no batteries and your grid-tie inverter must be 1 way? That sucks.
Click to expand...

You can make it 2 ways, but if you want to make it 2 ways, the paperwork you have to do it is seriously important and complicated and you have to pay some fees as well. Not worth at all.

Korishan said:
The reason for the not having batteries with a grid-tie or hybrid inverter is that in the event the main transmission lines get damaged, you won't be feeding the line with power from the grid-tie unit. They don't make the units be intermediate as in, mains power comes in, go through the grid-tie, then to the breaker box/panel. If this was the case, then the grid-tie/hybrid unit could shut off power to the mains side. But, this is not the case.
This is the biggest issue with most places that allow you to connect solar (or other alternative energy) in line with the grid. They don't teach or required the installers to install an ATS on the line so that when mains is not present, it disconnects that side from the house, thereby 100% eliminating the possibility of a linesman from getting shocked/killed. I don't get it, honestly. This should be a required device in all structures that are mains tied and an alternative energy source is added to the system. It just makes plain sense.
Click to expand...

I have never thought inthe linesman safety. For me this is a good reason, but as well there are systems to avoid this problem.
 
julianmh said:
Oderus420 said:
So you can have solar panels but no batteries and your grid-tie inverter must be 1 way? That sucks.
Click to expand...

You can make it 2 ways, but if you want to make it 2 ways, the paperwork you have to do it is seriously important and complicated and you have to pay some fees as well. Not worth at all.

Korishan said:
The reason for the not having batteries with a grid-tie or hybrid inverter is that in the event the main transmission lines get damaged, you won't be feeding the line with power from the grid-tie unit. They don't make the units be intermediate as in, mains power comes in, go through the grid-tie, then to the breaker box/panel. If this was the case, then the grid-tie/hybrid unit could shut off power to the mains side. But, this is not the case.
This is the biggest issue with most places that allow you to connect solar (or other alternative energy) in line with the grid. They don't teach or required the installers to install an ATS on the line so that when mains is not present, it disconnects that side from the house, thereby 100% eliminating the possibility of a linesman from getting shocked/killed. I don't get it, honestly. This should be a required device in all structures that are mains tied and an alternative energy source is added to the system. It just makes plain sense.
Click to expand...

I have never thought inthe linesman safety. For me this is a good reason, but as well there are systems to avoid this problem.
Click to expand...


Gotcha
 
Are you allowed to have a system hooked up to grid at all? Note that not feeding the grid is NOT the same thing as having an off-grid system

In sweden we are not even allowed to hook up a system that can send to the grid. No matter if you set it to 0 or not.. You need to have the papers done to have that system and last I checked this was mandatory in most countries.

Once again we are talking about grid-tie systems. No matter if you use them to sell or not. As soon as they are hooked up to the grid and can send that way there is very hard regulations to protect the grid and potential workers. For instance almost every chinese inverter that can do that part are illegal in Sweden if we gonna go that route :)
 
daromer said:
Are you allowed to have a system hooked up to grid at all? Note that not feeding the grid is NOT the same thing as having an off-grid system

In sweden we are not even allowed to hook up a system that can send to the grid. No matter if you set it to 0 or not.. You need to have the papers done to have that system and last I checked this was mandatory in most countries.

Once again we are talking about grid-tie systems. No matter if you use them to sell or not. As soon as they are hooked up to the grid and can send that way there is very hard regulations to protect the grid and potential workers. For instance almost every chinese inverter that can do that part are illegal in Sweden if we gonna go that route :)
Click to expand...

Dear daromer

You are right, if the system is hooked to the grid has to be officially register, doesn't matter if you sellor not the extra energy you produce.
And as you said, if you "sell energy-feed the grid" your system has to be certified by a technician to protect the grid and the workers.


As the rules here in Spain, (sunniest country in Europe) it is only made against solar power producers (Sun-taxes)
http://www.renewableenergyworld.com...s-sun-tax-discriminates-against-solar-pv.html

What I like to do is create a system, grid-tie (hooked) that never feeds the grid to avoid this taxes and that I can amplify-enlarge in the future (the house is on the build process right now)

I will start with agrid-tie/not-feedingonly solar (no batteries) system of around 1500w. Then I will put-on batteries, thesecan't be charged from the grid (to avoid extra taxes)
And depending on how fast I get the batterycapacity I needand I see how the system works, will try to increase power to 5000w andhopefullygets disconnect from the grid.

I am looking at different hybrid inverters and hook up controllers not to feed the grid right now, thank you for your help again! will keep watching your very interesting/helpfulvideos.
 
If you have no intention to feed back to the grid there is no use fiddling around with grid-tie systems nor Hybrid systems. It will only be extra legal hassle and cost. I would directly go for an off-grid system that you just redirect the parts of the house that you want to the inverter or the grid. The system will then make sure you got enough power.

No you wont/might not be able to use "all" energy but you wont be able to with a grid-tie system that you dont sell with either... Yes you need to hook up a smaller battery bank directly but in the long run you dont have to spend any money what so ever on grid-tie systems

Thats my 5 cents to it.
 
Initially that is what makes more sense for me, you are completely right.
But unfortunatelySpanish government considers off-grid systems the ones that:

There is no physical capacity of electrical connection with the transport or distribution network/grid at any time, directly or indirectly through its own or a third party installation. Off-Grid systemsdisconnected from the gridwithswitches or similar devicesshall not be considered off-gridfor the purposes of the application of this law.

Lot of companies/Electricity users have taken our government to court for this "stupid law" but might take years.
 
But that does not change what gear you have. What im talking about i off-grid inverters. Thats their definition... How its then hooked up and in legal part done in your place can be something else :)

So as the above says: "Off-Grid systems disconnected from the grid with switches or similar devices shall not be considered off-grid for the purposes of the application of this law"
So what Im trying to say is go for the correct gear directly. No use of paying extra for the "grid-tie" function when you never will sell any back to the grid.
 
daromer said:
So what Im trying to say is go for the correct gear directly. No use of paying extra for the "grid-tie" function when you never will sell any back to the grid.
Click to expand...

Which means you will have to either put in a Transfer switch before your mains panel to switch between either inverter and mains, or, you install a second panel that is fed by the inverter and you move circuits(breakers) over to that box. Thereby separating the two systems.
 
Korishan said:
Which means you will have to either put in a Transfer switch before your mains panel to switch between either inverter and mains, or, you install a second panel that is fed by the inverter and you move circuits(breakers) over to that box. Thereby separating the two systems.
Click to expand...
Off-Grid systemsdisconnected from the gridwithswitches or similar devicesshall not be considered off-gridfor the purposes of the application of this law.

This means even if you have a transfer switch the off grid system would be considered to be grid connected. To comply with the law there cannot be a switch between grid and off grid systems. The second circuit panel would work as it is only fed via the off grid inverter. Strict interpretation of the law

later floyd
 
daromer said:
But that does not change what gear you have. What im talking about i off-grid inverters. Thats their definition... How its then hooked up and in legal part done in your place can be something else :)

So as the above says: "Off-Grid systems disconnected from the grid with switches or similar devices shall not be considered off-grid for the purposes of the application of this law"
So what Im trying to say is go for the correct gear directly. No use of paying extra for the "grid-tie" function when you never will sell any back to the grid.
Click to expand...

I know what you mean... I use an off-grid system with a separate circuit at home for illumination, fridge, TV... and If for any reason need the grid for that circuit, have a hidden switch or "long cable" somewhere to get electricity from the grid.

The problem with this are that fines could go up to 60Million :(
https://www.mariscal-abogados.com/sun-tax-on-photovoltaic-systems-in-spain/

Korishan said:
daromer said:
So what Im trying to say is go for the correct gear directly. No use of paying extra for the "grid-tie" function when you never will sell any back to the grid.
Click to expand...

Which means you will have to either put in a Transfer switch before your mains panel to switch between either inverter and mains, or, you install a second panel that is fed by the inverter and you move circuits(breakers) over to that box. Thereby separating the two systems.
Click to expand...

Off-Grid systemsdisconnected from the gridwithswitches or similar devicesshall not be considered off-gridfor the purposes of the application of this law.

"Or similar devices"
I interpretate this like if I can feed the same circuit with Solar or Grid, will be considered as grid-tie.
And then comes the problem.
 
"With switches or similar devices" has the connotation of that the two circuits are tied together at some point. If there is NO switch or other device connecting the two units together, then they are not considered part of the law. They are separate.
 
I think you need to check with someone in your place for the legal perspective. Just beware of that grid-tie out of the equipment view is NOT the same as your mention of grid-tie when its hooked together in some way or another.

Just because you feed your grid into the device it shouldn't be affected to the same laws as grid-tie equipment. Since grid-tie is ALL about sending back to the grid.
I guess they don't care if you hook up a light bulb? That's essentially the same thing using a off-grid inverter or an inverter with ATS in front switching :)

At least that is how it works here.
 
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