LG Chem Resu vs BYD Batteries

[eberger45]

Hello,

I am building a house on a rural but grid-tied property in Sonoma Country, CA, which is in wild fire country. PG&E outages are now the norm every September & October, so we are planning to install solar + battery backup to ensure we can continue have critical loads run even during an outage. I've been working with Simply Solar and need to make a decision on battery choice. The solar system is a 13.76 kw system. The solar provider (Simply Solar) have two options for battery backup, either LG Chem ResU + SolareEdge StoreEdge inverters or BYD Batteries + SMA Inverters. The LG Chem + StoreEdge option is significantly cheaper and all the research I've done shows me that it's a reasonable, if not better option but the provider is suggesting the BYD Batteries for the following reasons:

* As far as I understand, the BYD battery has a slightly higher max surge than the LG Chem (7700 W vs 6600 W). I attached a couple data sheets that might help.
* LG Chem can only "back up" 4 breakers per inverter. BYD can cover your whole house. (with certain breakers excluded as needed)
* SMA/BYD is much more configurable - and expandable. LG Chem has a 10 kWh battery - get one or two per inverter. SMA/BYD can be installed in 10, 15, 20, 25, and 30 kWh increments.

The first bullet doesn't matter, honestly. 6.6 kw is plenty max surge and the second bullet feels like a nice to have - in case of a power outage we'd probably try to limit power draw to essential items anyway. The last bullet is potentially not ideal... I'd like to have more than 10kw of storage (they recommended 15).

Are there any other things I should consider WRT the difference between the setups? I get that a lot of this has to do with what we need / what we're building, so happy to provide more information if that's helpful. Thanks in advance!

[Mike90250]

1) Will you be using the battery daily, to offset peak power charges, or only for grid outages ?

2) if the latter, thats a VERY expensive battery only for 2x a year in outages, do they have a lead acid version avaib, or have you even considered a propane tank and generator ?

[travissand]

I'm off grid & a lot of my friends are too. 10 kilowatt-hours is enough for one or two cloudy days if you are conserving. Keep in mind a lot of average household use 60 kilowatt hours per 24-hours two-thirds of that is drawn during the night time. So it's all a matter of how much you want to pay for the few times you'll be without the grid. You can pay a lot and you won't have to conserve much it's all up to you.

I'm just here to say though that if you're conserving 10 kilowatt hours is enough especially if you have a backup generator. In fact like the previous comment you might consider just a backup generator and no batteries. I've been running my Honda eu2000 16 hours every night. Two gallons of fuel every night. Now I converted my Prius into a backup generator for when I'm parked at home at night and I expect it'll do better economy and with higher surge capacity. The Prius is complicated and I'm utilizing off grid hardware that I already have as part of my off-grid setup. If you choose the generator route you're probably best off with a Honda eu3000.

[eberger45]

Thanks both for the responses. One thing I didn't mention is that we definitely need some sort of backup given we're on well and septic and those systems absolutely have to be running in an outage.

We were considering a backup generator but would prefer not to burn propane from environmental reasons if we don't have to, even though being grid tied that means we would do it very rarely. The other reasons to have batteries as you mentioned Mike90250 is to offset power usage during nighttime/evening time when power consumption is highest but and avoid doing that during high-likelihood outage seasons, but then we'd probably be risking an outage w/o much backup power.

Are there any quick calculators that one can use to calculate how much money one might save peak shaving to see if its worth the costs?

[Ampster]

Hello,

I am building a house on a rural but grid-tied property in Sonoma Country, CA, which is in wild fire country. PG&E outages are now the norm every September & October, so we are planning to install solar + battery backup to ensure we can continue have critical loads run even during an outage. I've been working with Simply Solar and need to make a decision on battery choice. The solar system is a 13.76 kw system. The solar provider (Simply Solar) have two options for battery backup, either LG Chem ResU + SolareEdge StoreEdge inverters or BYD Batteries + SMA Inverters. The LG Chem + StoreEdge option is significantly cheaper and all the research I've done shows me that it's a reasonable, if not better option but the provider is suggesting the BYD Batteries for the following reasons:
...........
Are there any other things I should consider WRT the difference between the setups? I get that a lot of this has to do with what we need / what we're building, so happy to provide more information if that's helpful. Thanks in advance!

I am in a similar situation in Sonoma County on the grid. I also have two EVs. I looked at similar options including a Tesla PowerWall. I am an electronic hobbiest and went with a system that would allow me to make incremental increases in battery capacity. I was not concerned with surge capacity but more with being able to last through some cloudy days and a prolonged power outage. For the last two safety outages the skies were clear other than a little smoke.

As far as other things to consider, I would look at the ability of the inverter to leverage time of use rates by load shifting and I how user friendly those controls are. That is where you will get the greatest economic benefit. It will also give you a hedge against further erosion of the NEM beneficial time periods.
I have confidence in Solaredge, LG Chem and the large installed base of Solaredge users. It is probably too late for you to consider the SolarEdge battery because I don't think it is available in the market yet. SMA and BYD also have good reputations but I don't have any experience with them. BYD is a very large battery manufacturer (3rd largest in the world 60 gWhr capacity) and I think will be be a big factor in this country in the future.
Unless you are a DIYer, I would not even consider Lead Acid. It is a good choice for off grinders who have the time and knowledge to monitor their battery state of charge on a daily basis. The packaged Lithium systems your installer is recommending, while more expensive, offer low maintenance and good warranties.

[Ampster]

......
Are there any quick calculators that one can use to calculate how much money one might save peak shaving to see if its worth the costs?

Some installers may offer that and that may be a way to qualify bidders if that is still an option. I use a spreadsheet that I have been refining over the five years that I have been load shifting. I would share it but it is not user friendly. The concept is simple though. With PG&E peak rates as high as $0.50/kWhr and off peak rates as low as $0.15/kWhr any load you shift from peak to off peak allows you to consume thee times the power at the same cost.
Since you are in Sonoma County you may be able to benefit from some of the incentive programs that Sonoma Clean Power offers. If interested I can give you more options for energy conservation as others have suggested. This is a good time to build them into your home while you are under construction. I have converted my gas water heater to a heat pump and plan to converter my HVAC to heat pump technology.

[scrambler]

I don't know if Simply Solar can install them, but Electriq Power (electriq with a Q)has a hybrid system with a more modular (Panasonic) battery, you may want to check with them if they could install that instead.

[scrambler]

Are there any quick calculators that one can use to calculate how much money one might save peak shaving to see if its worth the costs?

I have a couple of spreadsheet I made to simulate NEM billing on a hybrid system, you are welcome to check them out to see if they help. I posted the links in at post #6 in the thread below
https://www.solarpaneltalk.com/forum...tes-with-an-ev

[travissand]

I disagree that lead acid is good for off-grid because they need to be fully charged often and in order to fully charge you have to charge them for longer than there is sun hours in the day. They're inherently bad for daily cycling. They're good for stand by use wear they sit on a float charge most of the time.

[Ampster]

I don't know if Simply Solar can install them, but Electriq Power (electriq with a Q)has a hybrid system with a more modular (Panasonic) battery, you may want to check with them if they could install that instead.

Panasonic may well be the largest battery manufacturer in the world if you consider their collaboration with Tesla. The market for modular batteries is growing rapidly and prices are dropping as manufacturers ramp up for the EV market globally.
The easiest way to compare prices for batteries is the price per kWhr of power stored.

[scrambler]

the second bullet feels like a nice to have -

You can get around the number of breakers limitation in the critical load panels, by using a 100 Amps critical load panel that has its own Automatic Transfer Switch.

One side of the transfer switch connects to the main panel with a 100 Amp breaker, so that all the loads in the Critical load panel can function normally when the grid is up
The other side of the transfer switch connect to the Inverter, so when the grid goes down, the critical load is fed by the inverter. At that point, you are responsible for not running too many of the critical loads at once, but you have more flexibility about which one you can use.

[Ampster]

I disagree that lead acid is good for off-grid because they need to be fully charged often and in order to fully charge you have to charge them for longer than there is sun hours in the day. They're inherently bad for daily cycling. They're good for stand by use wear they sit on a float charge most of the time.

I agree but there continues to be a large number of off gridders that stick to that old technology. Maybe it is the bottom line price and the distrust of newer technology. Off grid is a small niche market that will evolve over time. The large grid support batteries and the significant load shifting products on the market are all Lithium. My brother has a couple of rental homes on Maui and installed Tesla Powerwalls to leverage his solar and reduce his bill.

In this case the OP isn't even looking at anything but Lithium.

[eberger45]

Thanks all for the responses, this is super useful! @Ampster I'd love to connect with you to understand your setup given you're already in Sonoma and are faced with the same fire / power outage issues. Let me know if you're open to it. Not sure if there is a way to message someone privately on this forum.

[Ampster]

Thanks all for the responses, this is super useful! @Ampster I'd love to connect with you to understand your setup given you're already in Sonoma and are faced with the same fire / power outage issues. Let me know if you're open to it. Not sure if there is a way to message someone privately on this forum.

There is no way on this forum but I use the same handle on the teslamotorsclub.com forum and the outbackpower forum. There is messaging there or we can find some way to connect in Sonoma. I live just north of the city in Boyes Hot Springs. I have been regularly attending Sonoma Clean Power Community Advisory Committee meetings each month in Santa Rosa. I am retired so I am flexible. I am very interested in furthering the knowledge based of solutions to this issue.

[eberger45]

There is no way on this forum but I use the same handle on the teslamotorsclub.com forum and the outbackpower forum. There is messaging there or we can find some way to connect in Sonoma. I live just north of the city in Boyes Hot Springs. I have been regularly attending Sonoma Clean Power Community Advisory Committee meetings each month in Santa Rosa. I am retired so I am flexible. I am very interested in furthering the knowledge based of solutions to this issue.

Ah great, I'll join one of those forums and send you a message