How does grid-tied battery storage work.

In this video I explain how a grid-tied battery system works but it's also true of a Zappi charger or a hot water diverter such as an Eddi. I also explain why you are never full off-grid, even when you have plenty of battery power available.

[@Sanwizard1]

That was the most concise and simple to understand explaination I have seen on this topic! You should write the dummies book on the subject!

[@a_n_i_m_o_t_i_o_n_s]

Thanks for explaining..

[@gijbuis]

This is a excellent video explaining how the charging of an AC-DC home battery is regulated in order to minimize the charge coming from the grid. I have been looking everywhere to find out how this works. Your video is the first explanation I have found!

[@colinbrown9588]

I'VE FOUND IT! Been looking for days on how an AC-coupled inverter knows how to charge and discharge. Really thank you.

[@Electronzap]

Good information.

[@porshenn]

Very useful video, thanks!

[@KC08RAS]

Fantastic video straight to the point and very easy to understand

[@keithcress1335]

This was great! Thank you.

[@michaeldepodesta001]

Thank you that was really helpful. I am using a Power wall 2 with Solar PV and had noticed that compared with around 10 kWh/day of consumption I was still drawing ~0.1 kWh/day from the grid despite a full battery. Your video explains why and makes me think that the Powerwall is doing a pretty good job of balancing the various loads. You mentioned your self-consumption was around 95% but the Powerwall gives me around 99% self-consumption. Which I can now see is excellent.

[@NickNam3]

This is what i have been looking for, a Complete and Perfect explanation. Thank you!

[@noname1st139]

Very good advice,I think I'm now understanding, for some reason the batteries would discharge around the same time of day

[@TeeRMN]

What a quality video! Thank you Nicholas

[@nicholashowell]

Glad you found it useful.

[@ferryj6083]

Nice one, very helpful ✌🏻

[@nongeley2423]

Really informative

[@nicholashowell]

Glad you liked it.

[@kevinjackson6387]

Very interesting mate

[@stewartj00701]

excellent video, as someone starting out, would the Victron multiplus 2 GX do this same job?, I was looking to use a standard inverter and connect it to my home using Victron automatic transfer switches, when the battery voltage drops to 50% discharge the inverter cuts out which activates the transfer switch to grid power, and goes back to inverter when the battery voltage recovers to >90% but this grid tied approach seems more streamlined.

[@traveltogetherwithds9334]

Video was Great! I have a 7KW grid tied system in my home with a Solaredge inverter. The output from the Solaredge is connected to a 220V breaker in my main panel feeding the solar power to my homes panel. I am wanting to install a system in a vacation home with 48V Panels and Batteries. Do I feed the output of the Solax inverter into the main panel the same way as my Solaredge unit is connected?

[@answer4274]

Pretty. I also want such a system in my house. But one question. What happens if the public power grid stops working? How does my system at home continue to work?

[@thomaswwwiegand]

YES, that was interesting, thanks a lot. But that late switching might less happen in the night, as there only the usage and balance from grid or batteries might be. But 30 KW to pay instead of 100, as of store the solar local should be ok. I even think about to turn it off in the night, as I want to use it for power offs, and then only during the day with solar input (charge and balance that with he clouds), and later, when I got better data, maybe get in on in the early morning when more grid taking takes part, to empty the batteries to that time, the solar charge will start = balancing during the day + recharge, and keep the energy until I can risk to empty it, maybe from 2-4 am - as hold back for electric failure. Yes, I got better understanding ... as I now have only 2 OnGrid Solar (each about 2.000 Watt lunch time), and switch on off my aircon manual, when I see with 10 sec distance if there is enough (>800 Watt) to turn AC on ... . It works, as I sit at the PC most day and see the data ... still ok, but anyway I wanna a AC Storage as for this a lot electric failure here. Fridges, Internet and light ...

[@Chris-hy6jy]

Very well described. Do you have any make / model recommendations for this type of inverter charger? Something in the 1kW range is probably all i need to cover base load. I'm also in the UK. Thanks!

[@nicholashowell]

In the 1kW range, not really. I've played with a Sofar ME 3000 before and I think they are still available. It is a 3kW unit though.

[@davidcorlett2082]

That's the best video I've seen. I have only 1 question if someone can help. I have a hybrid on grid setup. from this video it would suggest I can connect directly into my fuse box and just add the flow connection to the live inbound cable after the smart meter? is it that simple? I will only have battery and grid linked in the inverter as the solar is on a different line. if I connect the ac in, where does the AC out go? Hope someone can help as I can't get my head around it to make sure I'm being safe. Thanks. David

[@nicholashowell]

Hi David. Adding an AC coupled battery inverter is not something that you should do yourself. It needs to be done by a qualified electrician to make sure it is safe. It is also notifiable work to the DNO and requires approval from them, especially if you already have Solar installed.

[@davidcorlett2082]

@@nicholashowell Thanks for the response. You wouldn't believe how difficult it's been to find someone to help, and till now still can't get anyone. I have written maybe 20 requests with only 1 local company getting back to me and they said if they weren't supplying the equipment they wouldn't be able to help, so no chance of a day rate piece of work. It's very frustrating as if I lived in the states it seems they can just diy it. Plumbing I will always DIY but like you say, electrical work can kill so I can design what I want it to do but not actually be able to do it. Probably why there's so few UK people with videos about this sort of thing. Regards, David

[@lipsee100]

Yeah your vid explain alot and helped me much,, Can you recommend the sofar Charge controller?

[@nicholashowell]

The Sofar ME3000 is quite good. It can charge/discharge at a maximum of 3000 Watts so if that is enough to cover your usage then I would recommend. It works good with Pylontech batteries too.

[@tomthomas5929]

Great explainer. Have you had to put in hardwired export limitation to satisfy G100 with the Sofar? I have 7.2kWp of existing PV with DNO permission for 5kW export. I'm looking at adding 3kW AC coupled battery inverter, but as I understand it I need some extra wirings up to make safe for DNO?

[@nicholashowell]

The Sofar was used as an example. I actually have a hybrid DC coupled inverter.

[@nadeekajayaweera742]

What u explained only for hybrid inverter Is that correct?

[@chrisdolan4815]

Hi Nicholas, brilliant videos and content, with your solax hybrid inverter what is the charge rate to the Pylontech? when your solax setup are producing at their max rate 5 kw do you end up losing power that doesn't go to the pylontechs ?

[@nicholashowell]

The charge rate is 2500W to the batteries so you are right, I would export some if I was producing 5000W. However in practice this almost never happens as I dump any excess into my cars, immersion, dishwasher etc using my automation system MonACle.

[@robertjumpp3268]

@@nicholashowell Hi do you havd a git for your MonACle or could share? I’m about do go down the Victron Multi II with pylontechs route and wondered if yours or some open source software could help manage it. And if you could start again would you still go pylontech or choose another like byd. As im finding buying batteries in the uk very difficult. Many thanks Rob

[@nicholashowell]

@@robertjumpp3268 Sorry but MonACle is not ready to be used by anyone else, it still needs much work. I would have to write an adapter for the Victron for it to work and that would take time as I would need one to test with first. I would still go with the Pylontech batteries, I'm happy with them.

[@robertjumpp3268]

@@nicholashowell Thank you anyway. Keep up the videos, I'm on a bing and really enjoying them. Cheers

[@JohnIsodore]

Hei, really nice video. It answered a lot of my questions, but i have 2 left.1. Why did you choose to use AC as the common voltage between the solar and battery, rather than just keeping it DC and having a only one box connected to the grid? 2. Can a system like this give you power if the grid is down? If not how would that change the system? Would love a video on this :)

[@nicholashowell]

I think I did mention in the video the advantage of having AC coupled batteries vs DC coupled batteries. Both systems can technically operate in an off-grid mode. Grid tied inverters need to sense the grid to operate. If it goes down they stop working. They usually have a second set of AC outputs that can be used in off-grid mode and from these you can run a critical circuit in your home (say to supply the fridge, freezer, lights, TV and broadband). This circuit must be isolated from the grid so that no power can leak out on to the grid that might harm people working on the lines. So you need a transfer switch that will disconnect the circuit from the grid and connect it exclusively to the secondary outputs of the battery inverter. I will try to make a video about it at some point, thanks.

[@JohnIsodore]

@@nicholashowell thanks for the good answer. What I am trying to go for is a on-grid system with solar and battery backup, but I don't want everything to go through my charge inverter, so I am looking into a victron Quatro with a phase controller and a relay to stop islanding. Specifically the zeihl urf1001e. They are selling it too on the victron page.

[@nicholashowell]

@@JohnIsodore Wow, that's looks like a serious bit of kit. Myself, I just have a manual changeover switch. It costs a lot less than that one but does mean I have to change it over manually in the event of a power outage. For me a manual one is fine because in the 8+ years I've had my system I haven't yet had a power cut to use it 😒

[@JohnIsodore]

@@nicholashowell haha, you have to fabricate your own power cuts. I too consider this, manual isn't that hard and it's not like I do something that important home that I don't have time to switch. I look into the cost, maybe I will upgrade later.

[@chrisrebar2381]

Hi Nicholas. Great video. The system I am planning to install is one that takes a feed from the grid ONLY to top up the battery bank when my solar panels are not creating enough energy. I am not interested in feeding anything back to the grid. I also want to stop any statistical data being gleaned by my energy supplier (I have a "smart" meter installed and they will not remove it) - so basically, all they can glean is that I am using X amount of energy to charge my battery bank. So, in simple terms: 1) Grid supply to dedicated consumer unit to battery inverter for charging 2) Battery inverter to the house consumer unit 3) A switch for switching to a separate dedicated “critical appliances” circuit in the event of grid failure 4) Generator battery charging in the event of grid failure My question(s): Is this classed as a “hybrid system” and, since it does not feed back into the grid and do you think it will need DNO approval (again because it does not feed back into the grid) Sorry this was a bit long winded

[@nicholashowell]

Hi Chris. I think you are confusing the term hybrid system with grid-tied system. A hybrid inverter is simply an inverter that contains both a solar inverter and a battery charger/inverter in the same unit. It is my understanding that if you are using an off-grid inverter that you would not need DNO approval since it does not back feed onto their network. I'm not sure what it is you want to achieve but if you want to run your house distribution board from an off-grid inverter (like the one I have in my power shed) then you need to consider what your maximum power draw will be since your inverter will only be able to supply up to a maximum amount of power. My shed inverter is 5kW so the off grid circuit that it supplies must never exceed this amount of power. I think you would be better off with a grid tied system especially as you are going to be connected to the grid anyway. A smart meter does not know what you are using power for, just how much you are using at any give moment. I don't think you need to be so concerned on that front.

[@chrisrebar2381]

@@nicholashowell Thanks for the prompt reply What I am trying to achieve is a system that reduces my reliance on the grid as much as practically possible - similar to yours I guess The use of the word "hybrid" was basically to describe a system that draws power from the grid and solar PV, nothing to do with inverters - probably not the best word to use in this particular instance The most important thing is to have battery backup to power my "critical appliances" circuit (3 x 13amp sockets and a water heater) in the event that these fruitloops that seem to be running our country at the moment start their "climate change lockdowns" - which I believe is a very real and immenant possibility .... Call it insurance :-) Re. so-called smart meters, yes I understand that they do not know what I am using power for - its just that I do not like them "spying" on my detailed usage - and more importantly, the time of that usage, so any way I can attempt to "scupper" that, I will! "maximum power draw" - Yes, I understand So, thanks again for your reply

[@chrisrebar2381]

@@nicholashowell Just as a "by the way", I was working on one of the first companies to trial data feed back over powerlines back in 1991 (London Electric). This work highlighted the potential for "behavioral usage" analysis and how this data can be used - or more importantly, misused. Anyway, if you are interested then this link explains in more detail what I mean smartgridawareness.org/privacy-and-data-security/how-smart-meters-invade-individual-privacy/

[@nicholashowell]

@@chrisrebar2381 I think I get what you want to do now. In all honesty you are probably better off with a grid-tied hybrid inverter like my Solax unit. It will only pull from the grid when there isn't sufficient solar or battery to supply the loads in your house. So most of the time you will not be pulling anything from the grid and your smart meter will see nothing. You can charge the batteries from the grid at night if you so choose (for those winter days when there isn't enough solar to give you enough charge). It also has an off grid function so that it can continue to operate in the event of a grid down situation.

[@chrisrebar2381]

Nicholas Howell Thank you very much. You're a talented man and your time and effort to create these very informative videos is greatly appreciated. I will try not to bother you again :-)

[@MrKlawUK]

should the import and export ‘bleed’ be roughly equal? as you turn on/off devices or solar varies? I don’t get paid for export yet, and am getting around 1kwh a day also. But if I get signed up to an export tariff, that’d help offset at least some of it

[@nicholashowell]

It's a good question. I've not measured so I don't actually know. My guess would be that they should be similar.

[@con-king]

Now what happens if the grid goes down? Will the inverters still supply energy to the loads if there is a transfer switch in place between the loads and the utility meter? Or do you lose power?

[@nicholashowell]

Some inverters have an EPS (Emergency Power Supply) function. In the event of a grid down they activate a second set of outputs. From this you can run a critical loads distribution board. You would put circuits like lights, fridge/freezer, TV and broadband on that critical panel. Like you say you would need a transfer switch between that critical loads distribution board and your main distribution board so that only the grid or the EPS is supplying it power but not both.

[@nadeekajayaweera742]

Can you explain whether CT clamp is only for hybrid inveterate I have Growatt 5000ES

[@nicholashowell]

If it has a battery and it's grid tied then it will almost certainly have a CT clamp. Some non battery inverters also have them so that they can limit export.

[@MePeterNicholls]

So if I want to grid charge battery at night and use battery only during day, how’s that achieved?

[@nicholashowell]

An AC coupled battery system (inverter + batteries) will do that for you. So long as your daytime use doesn't exceed the maximum output power of the inverter and you have a big enough battery to cover you daytime use you shouldn't use any grid power. You can tell most inverters to charge from cheap rate.

[@Joelwilly57]

What inverter would work best for this application ?

[@nicholashowell]

There are many. I've experience with the Solax and Sofar brands, both are good. A Tesla power wall also works like this.

[@phearl3ss1]

So what happens if the grid loses power does it shut off so that the inverters not providing power to the grid

[@nicholashowell]

Yes. Though some have an EPS mode and will power a separate output in a grid down situation. Useful to plug your freezer and fridge into.

[@caniolancellotti4501]

can i use not second inverter but powmr 60A battery recharger?

[@nicholashowell]

I'm not sure I understand what you mean?

[@caniolancellotti4501]

@@nicholashowell i have inverter growatt mic 3000TL-x , i want use battery is possible?

[@nicholashowell]

@@caniolancellotti4501 Yes it is possible. You will need to get an AC coupled battery inverter.

[@darkflux]

So what if your batteries are full? What does the system do with the solar energy influx?

[@nicholashowell]

On a grid-tied system once the batteries are full the rest will be exported to the grid.

[@darkflux]

@@nicholashowell i thought the purpose of that sensor was to stop that from happening?

[@nicholashowell]

@@darkflux Only to fill up your battery. Once it's full you have no use for the solar and anything not being used directly by your house will be exported. If you don't want that to happen then you need an off-grid inverter that will just stop taking energy from the solar panels once the battery is full. Off-grid inverters have their own limitations though.

[@darkflux]

@@nicholashowell so what does an Off-Grid Inverter do with the extra solar energy?

[@nicholashowell]

@@darkflux Nothing. Once the battery is full it only pulls power from the panels to satisfy any load. If there is no load, it simply doesn't pull any power from the panels.

[@SkypowerwithKarl]

If you’re in California, don’t waste your time with grid tie. The regulations call for the utilities to control your system, this benefits them, not you. The grid inverter and permits money would be better spent off grid batteries to keep and use what you make. In Santa Clara county permits can take up to a year and the inspectors will often require changes that aren’t code and not safe. Incompetents

[@martinbartlome136]

Perfectly explained! Now the only question left is where do I get the Battery Inverter and the appripriate CT Clamp to jump-start experimenting with my solar system that is actualy only grid-tied?

[@nicholashowell]

I've seen some Sofar ME3000 going second hand on eBay (UK). These work with Pylontech batteries.

[@martinbartlome136]

Oh, good idea. I'll check that. i have seen some of the CT clamps on Amazon as well but i cannot determine how to size it to fit my solar Grid-Tied installation.

[@nicholashowell]

@@martinbartlome136 The calculation depends on many things but not all will be important to you. Some things to consider are, how much do you use on a typical day, what is your peak draw, do you want to store everything you generate or just enough to get you through the night? Alternatively, you could just start with a US5000 and see how you get on. If you find you need more, just buy another one.

[@rodricksage5963]

you know, it's funny how people can't see the logic of, connecting the battery to the grid, and use the battery instead of the grid, i have to explain is like a water tanker, you connect the water tanker to the water grid, let it build up and just use the water of the tanker. sure, your first bills will be high but, then is just going to drop like an apple from a tree.

[@N8Dogg1002]

Looks like you robbed a vape shop! Lol!!