Adding a powerwall to a grid tie sunnyboy 5000tl

I

Icy Strait

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Looking for some opinions on the best way to add battery storage to an existing grid tie system.

Power hereis .64/kWh and the local utility doesn't offer net metering. Right now they are happily taking my excess power for freeand selling it elsewhere.

My system is a sunnyboy 5000tl and 5kw of solar panels. It seems the convensionalway to add battery storage would be to AC couple with a sunnyboy island. Just wondering if anyone here is running that setup and how they like it? Can the sunnyboy island be configured to safely charge lithium batteries?

Maybe AC coupling isn't the answer. Any other ideas?

Thanks.
 
gpn said:
Where the heck do you live?
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An island in Alaska.
Our utility is 25% hydro, 75% diesel generation.
Living here, you get a super fast ROI if you go solar.
 
hbpowerwall said:
https://rover.ebay.com/rover/1/705-...nverter&_frs=1&campid=5338073988&toolid=20008 Yep know a few running the Island invertser but they are pricy - defiently something i would like to look into
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Mysunnyboy 5000tl grid tie inverter has a minimum input voltage of 250VDC, so I can't put my 48v powerwall between the panels and inverter (and skip AC coupling altogether).
Maybe I should just build another solar system for my battery with an inexpensive battery inverterand use a transfer switch to hook it up for night duty. Might even be able to get fancy and control the transfer switch with the Batrium or a raspberry
 
IcyStrait said:
...Maybe I should just build another solar system for my battery with an inexpensive battery inverterand use a transfer switch to hook it up for night duty. Might even be able to get fancy and control the transfer switch with the Batrium or a raspberry
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Thats gonne be the smarter, cheaper way to do it ... damn, those Sma sunnyboy island's are expencive ...
 
Hi Icy,

Based on the description of you system I think we have a similar setup. What I am researching is to use AC power to charge the batteries and to feed DC from the batteries into the inverter. Maybe we can compare notes.

My setup would allow me to use the third DC terminal of my SMA inverter as a battery input. The concept would look as follows for 48VPowerwall(going from AC to the inverter):

AC In
48V 10A AC-DCPower Supply
48V 30A Charge Controller
48V 45A BMS
1.5kW 18650 battery block (13S14P)
48V DC Step Up (to the minimum voltage of the inverter)
5.0kW SMA Inverter
AC Out

I guess if you don't use all the DC terminals of your inverter, this might be an option for you as well.
 
IcyStrait said:
Looking for some opinions on the best way to add battery storage to an existing grid tie system.

Power hereis .64/kWh and the local utility doesn't offer net metering. Right now they are happily taking my excess power for freeand selling it elsewhere.

My system is a sunnyboy 5000tl and 5kw of solar panels. It seems the convensionalway to add battery storage would be to AC couple with a sunnyboy island. Just wondering if anyone here is running that setup and how they like it? Can the sunnyboy island be configured to safely charge lithium batteries?

Maybe AC coupling isn't the answer. Any other ideas?

Thanks.
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Depending on your maximum load one option would be connect the solar into standard 48V charge controllers (2-4 in your setup ?) into a 48V battery pack and attach a standard 2nd hand UPS (3kVA max for 48V pack). Have a separate charger plugged into the mians set at a very low voltage attached to your battery pack so when the pack voltage drops enough the power is drawn through the charger or just put plug the UPS in to bypass the battery. The battery will still be charged via the solar.... This route minimises the number of voltage level changes and efficiency losses.
The downside to this specific setup is you are limited to maximum load of 2kW per item via the battery as you can always connect another UPS unit in parallel.

Correction - 3kVA/2.7kW for the older APC 3000VA models
 
IcyStrait said:
Looking for some opinions on the best way to add battery storage to an existing grid tie system.

Power hereis .64/kWh and the local utility doesn't offer net metering. Right now they are happily taking my excess power for freeand selling it elsewhere.

My system is a sunnyboy 5000tl and 5kw of solar panels. It seems the convensionalway to add battery storage would be to AC couple with a sunnyboy island. Just wondering if anyone here is running that setup and how they like it? Can the sunnyboy island be configured to safely charge lithium batteries?

Maybe AC coupling isn't the answer. Any other ideas?

Thanks.
Click to expand...
I don't know the specs of your inverter, but there are two ways you can go. A) change to hybrid inverter B) use somthing like a Victron Multi. This is a workaround which allow you to continue with your SMA inverter, but systemlosses will be somewhat bigger. Not shure what will be the most economical soulution in your case. Victron multi comes in different sizes and versions. https://www.victronenergy.com/inverters-chargers
 
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