Grid tie DIY battery backup

Beenlouis

New Member
I am new to solar and am currently running a grid-tie Enphase IQ7 solar system. I live in a region in which the power company will not buy back any overproduction (I am the first to have solar for my utility company, which means the laws and regulations around solar are almost non-existent). I would love to explore a battery backup system that would capture my overproduction and allow me to retain that electricity for later. I would love to use the end phase battery backup system, but can't justify spending $18,000 on a battery backup system. Would it be possible to do my own grid tie battery backup system to capture this overproduction? Any thoughts I appreciated 🙂
 

Samsonite801

Solar Addict
Yeah, there are a lot of threads here on building your own DIY battery banks, using with a hybrid all-in-one inverter... You can go as many kW/h as you can afford, and buy cells straight from China for best value.
 

svetz

Works in theory! Practice? That's something else
@svetz is an expert, maybe this incantation will summon him.
ROFL... not an expert by any means.

I have Enphase IQ7's the Ensemble system. They recently knocked the price of Ensemble down a bit, but still pricey.

You don't have to use the Enphase Encharge batteries, Enphase is compatible with Tesla and possibly others. The "traditional" solution before AC batteries was to use an AC coupling solution.

The problem with putting a DIY battery on microinverters is that there needs to be a brain/system to control the microinverters for a variety of complicated reasons (see Incrementally Adding AC Batteries).

That said, there has been a very interesting recent development which I've speculated in #274 for putting a DC battery (DIY or otherwise) with an inverter onto the Enswitch.

...I live in a region in which the power company will not buy back ...would love to use the end phase battery backup system, but can't justify spending $18,000...
Any Battery system is going to be $$$. There's always something like Crappy Net-Metering agreement in Your Area? Crypto mine instead! but that sounds like gambling to me. You might also look into banking the power in other ways (e.g., lower the thermostat or freeze ice during peak solar to cool the place when off-peak then let it coast up after peak, set your water heater to only turn on when there's enough sun, charge the EV at solar-peak times).
 

solar8484

Solar Enthusiast
I am new to solar and am currently running a grid-tie Enphase IQ7 solar system. I live in a region in which the power company will not buy back any overproduction (I am the first to have solar for my utility company, which means the laws and regulations around solar are almost non-existent). I would love to explore a battery backup system that would capture my overproduction and allow me to retain that electricity for later. I would love to use the end phase battery backup system, but can't justify spending $18,000 on a battery backup system. Would it be possible to do my own grid tie battery backup system to capture this overproduction? Any thoughts I appreciated 🙂

If financial justification is important to you then batteries are probably not a good fit for you. And you are not alone, there is <5% of home solar systems with home batteries even after years of heavy vendor sales push and government subsidies. In general, batteries are the most expensive power source. If your power company requires no export to grid then you can setup zero export limiting for your solar system at much lower cost than batteries. Otherwise, max out your A/C or heater :cool:
 

MisterSandals

Participation Medalist
If financial justification is important to you then batteries are probably not a good fit for you.
Absolutely
I would love to use the end phase battery backup system, but can't justify spending
This backup system won’t pay for itself unless you weigh in knowing you are prepared for power outages. You will recoup by saving refridge and freezer contents and some comfort power too. You have to place a cost/benefit on that.
 

osolow

New Member
ROFL... not an expert by any means.

I have Enphase IQ7's the Ensemble system. They recently knocked the price of Ensemble down a bit, but still pricey.

You don't have to use the Enphase Encharge batteries, Enphase is compatible with Tesla and possibly others. The "traditional" solution before AC batteries was to use an AC coupling solution.

The problem with putting a DIY battery on microinverters is that there needs to be a brain/system to control the microinverters for a variety of complicated reasons (see Incrementally Adding AC Batteries).

That said, there has been a very interesting recent development which I've speculated in #274 for putting a DC battery (DIY or otherwise) with an inverter onto the Enswitch.


Any Battery system is going to be $$$. There's always something like Crappy Net-Metering agreement in Your Area? Crypto mine instead! but that sounds like gambling to me. You might also look into banking the power in other ways (e.g., lower the thermostat or freeze ice during peak solar to cool the place when off-peak then let it coast up after peak, set your water heater to only turn on when there's enough sun, charge the EV at solar-peak times).
Hey,
Im new but been have been reading a few hours and your post stood out to me I mine crypto and have 51 REC Alpha black 365W with IQ 7+ Micro inverters with grid Tie 1 for 1 net metering and 20KW Generac generator for backup but when my power goes out it takes a few sec before my generator Kickes in and messes up all my miners, my power usage is pretty high about 10-15,000 watts about 300KWH a day all im looking for is someting to give me that 15-30 sec for my generator kicks in besides buying the Enphase battery do I have any other options? That's what my dealers trying to sell me and I'm not crazy spending that type of money for the few seconds I need...
Thank you for any input I love all the info I'm finding here..
Thanks
Solo
 

Cheap 4-life

Solar Enthusiast
I could not feed into the grid unless I wanted to pay 20k+ and jump through hoops.
I’m using battery powered grid tie inverters with limiters. I’ve got roughly $6500 into the entire setup. My electric bill is near zero. ROI is 7 years. In my area batteries to save excess solar production is indeed worth it and will save me a lot after another 4 years.
 

solar8484

Solar Enthusiast
Hey,
Im new but been have been reading a few hours and your post stood out to me I mine crypto and have 51 REC Alpha black 365W with IQ 7+ Micro inverters with grid Tie 1 for 1 net metering and 20KW Generac generator for backup but when my power goes out it takes a few sec before my generator Kickes in and messes up all my miners, my power usage is pretty high about 10-15,000 watts about 300KWH a day all im looking for is someting to give me that 15-30 sec for my generator kicks in besides buying the Enphase battery do I have any other options? That's what my dealers trying to sell me and I'm not crazy spending that type of money for the few seconds I need...
Thank you for any input I love all the info I'm finding here..
Thanks
Solo

First, Encharge and most other home battery systems do not guarantee no device/computer reset whenever the grid goes down. It may happen depending on the where the AC power cycle is when the grid goes down but it's not guaranteed. It's an inherent limitation of all line-interactive backup power systems. If you want 100% guarantee then look into double-conversion online UPS which will provide clean power at all times and zero transfer time until your generator kicks in when the grid goes down. A few 5 KVA units should meet your power capacity needs. They are not cheap but still significantly less than home battery systems of equivalent power capacity. If you can accept refurbished units then the cost could be quite a bit lower.
 

NHRenewables

New Member
I am new to solar and am currently running a grid-tie Enphase IQ7 solar system. I live in a region in which the power company will not buy back any overproduction (I am the first to have solar for my utility company, which means the laws and regulations around solar are almost non-existent). I would love to explore a battery backup system that would capture my overproduction and allow me to retain that electricity for later. I would love to use the end phase battery backup system, but can't justify spending $18,000 on a battery backup system. Would it be possible to do my own grid tie battery backup system to capture this overproduction? Any thoughts I appreciated 🙂
Install a AiO, add a critical load panel downstream, and you’ll take back control of the Kw your system is producing. Size your battery to your 24hr consumption.
 
Top