Powerwall advise please

Hi all

I was wondering if anyone could point me in the right direction on how to build a powerall 2 AC verison. From what I've read it's an all in one unit, has inverter and charger built in.

My current system consists of 12 solar panels all with power optimizersgenerating 3.4kw. connected to a solaredge se4000 inverter.

I like the idea of the powerwall 2 because I can install it without having to touch my current system.

I can't seem find anyone that has built a system that is stand alone like the powerwall 2. ie battery bank that has a lithiumion ACbattery charger and invertor which monitors your incoming supply which charges the batteries if your generatoring more than you are using and supplies you with AC when you need it. Also stops when your battery bank is to low.

manythanks

Carl

People havent built it like that because it ends up in more equipment and in many case higher cost.

Doing above can easily be done with cheap charger + grid tie inverter that you can control or run by itself with 0meter. Hook this up to some control unit like raspbery or any other that make sure it do what it should when you want it too.

Hi, I am trying to figure out how to make a powerwall too, with a"seems to be" special configuration and similar to Carl's needs. Here at Spain you can't have a grid tied installation without a lot of problems, projects, licenses and of course paying, even paying for the current you feed-in to grid, you pay for use the net as back-up. There is no net balance system.
So to avoid all this you must have you solar system unconnected from grid, or at last ensure not to feed-in the grid.

My utopic system would be a grid tied system, with batteries, that will consume from batteries while have enough power and it will automatically switch to grid when batteries are discharged. Next day when sun come it will start charging batteries and power the house and if batteries are full only produce the energy needed to power the house but not to feed-in the grid.

MPP Solar Hybrid Inverters have 3 modes and none of those will fit my needs.

GridFree inverter will stop producing power from panels if you don't consume from grid with an external current sensor but can't manage batteries charging.

https://www.ev-power.eu/Micro-Inverters-1/GridFree-AC-Inverter-SUN-2000GTIL2-LCD-45-90V.html?cur=1

I don't know if there is a device that makes it all or as daromer says I must create a system with a raspberry or arduino that controls panels and batteries side to connect or disconnect to a normal grid tied inverter depeding of house consumption.

Regards

You only need an offgrid inverter. Mpp have that. Look at PIP series for instance. Note that the Hybrid also does exactly what you whant = not feed into grid.
I have both versions here and i ran them both like that before i was allowed to feed into the grid.

But if you talk about feeding back into the grid but only to feed your house you dont need any "switch" then your talking about something else and that is 0metering. I do not recomend that for setups where your not allowed to feed into grid because in most places its not even allowed. (Heavy fines...)


Regardign feeding to grid from battery. No there arent that many out there because i look for that too. There are som but you either need to stick with the more expensive ones or go china model and hope for the best.

jesusangel said:

Hi, I am trying to figure out how to make a powerwall too, with a"seems to be" special configuration and similar to Carl's needs. Here at Spain you can't have a grid tied installation without a lot of problems, projects, licenses and of course paying, even paying for the current you feed-in to grid, you pay for use the net as back-up. There is no net balance system.
So to avoid all this you must have you solar system unconnected from grid, or at last ensure not to feed-in the grid.

My utopic system would be a grid tied system, with batteries, that will consume from batteries while have enough power and it will automatically switch to grid when batteries are discharged. Next day when sun come it will start charging batteries and power the house and if batteries are full only produce the energy needed to power the house but not to feed-in the grid.

MPP Solar Hybrid Inverters have 3 modes and none of those will fit my needs.

GridFree inverter will stop producing power from panels if you don't consume from grid with an external current sensor but can't manage batteries charging.

https://www.ev-power.eu/Micro-Inverters-1/GridFree-AC-Inverter-SUN-2000GTIL2-LCD-45-90V.html?cur=1

I don't know if there is a device that makes it all or as daromer says I must create a system with a raspberry or arduino that controls panels and batteries side to connect or disconnect to a normal grid tied inverter depeding of house consumption.

Regards

Click to expand...

Hi,

we have a similar situation here in Germany, lots of regulations and paper works if you want to use the grid as backup. In addition, we also have to pay for the power we produce and feed into the grid, so this solution doesn't make any sense at all to me.

That's why I decided to use my system completely off-grid with automatic switching between grid and batteries, depending on the charge state of my batteries and the power produced by my solar system. Therefore, my system has separate charging and inverter sides, both with seperate devices.

I have 3 solar string (3.8 kWp) and 3 charge controllers charging (with max. 80A) all the same battery bank (hybrid lead-acid/Li-Ion, overall capacity 1360 Ah/56 kWh @24 V) and a 3000 W 1-phase converter with auto-switching (switching time < 10ms, most devices don't notice that at all) that powers most of house (remaining average grid consumption is 0.5 kWh/day). The inverter has also a built-in charger (that takes the power from the grid), but I don't use it, since I generate enough power during daytime with the solar system.

On a sunny day, I power my office (~500 W overall) for 8-10 hours and the batteries are fully charged for everything I want to power in the evening and during the night.

So, I would recommend using seperate charge controllers and inverters, no feed into the grid. Since I don't want to advertise here, just send me a private message and I'll tell you which products I'm using .

Have sun!
Oliver