help for existing grid tied system to add battery

[zanydroid]

So you want to save that $1,500 every year. For example, a 5 year pay back gives you a budget of $7,500.
How many Enphase IQ batteries does that buy and would they provide enough capacity to offset 90%+ of the kWhrs listed on the year end catch up?

Note the payback requires the $7500 +30% system to actually be able to recapture all $1500

If the system only has 1kwh of battery, it won’t be able to do that. (Also would not meet minimum threshold for 30% )

 

[BigEdHB]

All of those will.

Some will also let you defer export at the peak rate. Normally you export 90% of solar at the off peak rate. It depends on what modes are supported. 18kpv has the mode. I am not sure it is legal to turn on in all POCO in California

Yes, i would just stick with the main goal of night usage. I will look into this, thank you.

 

[BigEdHB]

So you want to save that $1,500 every year. For example, a 5 year pay back gives you a budget of $7,500.
How many Enphase IQ batteries does that buy and would they provide enough capacity to offset 90%+ of the kWhrs listed on the year end catch up

Bentley, do you do installs? I'm in Riverside county

 

[zanydroid]

Are you 0kWh from grid but still need to pay due to TOU? It seems implicit but i like to make things super clear.

 

[Hedges]

mid peak generation and delivery 0.61 per kwh
I think they give me back 0.10 but this is the winter rates I would have to dig up summer rates

If the spread between buy on-peak and sell off-peak is $0.50, your payback should be 1/2 what I estimated from my California rates. Like 4 years vs. my 8 years.

FWIW there are occasional fire sales on grid tie code compliant batteries on eBay etc. That might significantly boost your ROI.

Note however that batteries and inverters are joined at the waist in the current regulatory environment. So you have very little freedom in mixing and matching (it’s not zero, but also not free market)

IOW buying a battery on fire sale without understanding the inverter you are allowed to use it with will be a sad day potentially

Certainly the case if UL listed ESS now required.
For a while, AGM was exempt. But they cost $0.50/kWh of cycle life, so a non-starter for time shifting.

I bought a few Sunny Boy Storage and LG RESU-10H through eBay. Prices were 1/4 to 1/8 of retail so might cost me $0.07/kWh and can make sense.

Most of the RESU listed say the batteries are swelling. I don't recommend anyone go this route; look for LiFePO4.


The LG PowerPro looks quite attractive. I don't think it is part of a UL Listed ESS except with EG4 18kpv, for now.

 

[zanydroid]

Certainly the case if UL listed ESS now required.
For a while, AGM was exempt. But they cost $0.50/kWh of cycle life, so a non-starter for time shifting.

OP is in California so maximal requirements

Most of the RESU listed say the batteries are swelling. I don't recommend anyone go this route; look for LiFePO4.

If they’re extremely cheap you could get permitted / PTO and then throw them away (via Craigslist giveaway, proper waste disposing will probably be $$$) and switch to $200/kWh rack mounts or and AliExpress hybrid inverter or whatever else you want.

The LG PowerPro looks quite attractive. I don't think it is part of a UL Listed ESS except with EG4 18kpv, for now.

MidNite is coming out with their own PowerPro and paired inverter this year. Similar price point, UL9540

 

[solar8484]

average $125. was told that Time of use was the reason for this. I'm hoping to be able to draw from a battery source once the sun goes down but still be on the grid

Assuming that's all due to peak time consumption then you are probably using ~7kWH (@$0.6/kWh) between 4-9pm. The lowest cost home battery option is probably a single Enphase 5P without backup for under $10K installed ($7K w/tax credit). A single 5P might be able to cut the peak time grid consumption by 4kWH. If the NEM credit for export is $0.1/kwH then that could mean ~$720 savings per year. So, you could break even under 10 years. Not great but still under the warranty period.

 

[zanydroid]

up for under $10K installed ($7K w/tax credit)

What is the typical markup or labor cost in U.S./California for AC coupled storage retrofit?

 

[solar8484]

What is the typical markup or labor cost in U.S./California for AC coupled storage retrofit?

I've seen ~$3K installation cost for a single Enphase 5P with no backup assuming no major electrical upgrades required.

 

[BigEdHB]

Are you 0kWh from grid but still need to pay due to TOU? It seems implicit but i like to make things super clear.

no, they are charging me time of use, so it's averaging about $125 overage which really isn't too much .61 a kwh i believe the grid tie in cost is $30

 

[BigEdHB]

I've seen ~$3K for a single Enphase 5P with no backup assuming no major electrical upgrades required.

okay, I'm assuming your suggestion for the enphase 5p is because of my system. Does this battery require any other equipment to use or will my system suffice?

 

[1201]

no, they are charging me time of use, so it's averaging about $125 overage which really isn't too much .61 a kwh i believe the grid tie in cost is $30

Do you care to post your last bill? Personal data removed of course

 

[solar8484]

okay, I'm assuming your suggestion for the enphase 5p is because of my system. Does this battery require any other equipment to use or will my system suffice?

Without backup capability, the Enphase 5P only requires the Combiner (with included Envoy) that you should already have with your iQ8's.

 

[Hedges]

Do you care to post your last bill? Personal data removed of course

no, they are charging me time of use, so it's averaging about $125 overage which really isn't too much .61 a kwh i believe the grid tie in cost is $30

If your cost is $0.61/kWh, GT PV, or zero-export for daytime use, or PV + battery ought to be able to reduce that.

$1500/year of which $1150 is power usage. $11k investment would be 10 year payback, or about eternity considering time value of money and breakdowns.

See what can be accomplished spending no more than $5k.
Or more, if you bet on rate increases or want to pay for backup during grid outages.

Since you already have a system, adding more of the same could be easiest. But if you're grandfathered under NEM 2.0, that would be lost if adding > 1 kW so not worth doing.

PowerPro battery by itself is $4000. Add inverter and about $8000? After tax credit comes close to my $5000 target, if balance of system costs you nothing.

Difficult to make this pencil out with good returns.

 

[zanydroid]

PowerPro+18kpv is $10K pre tax.

If you DIY in the Enphase 5P it's $4K pre tax on Renvu's eBay storefront, which is a very good ROI on top of also staying within the ecosystem. So presumably one can even drive up to CED Greentech or Renvu local branch with a truck and load it up for low delivered cost.

I would expect PowerPro+18kpv to have a higher install cost for non-DIY. And for DIY it would probably cost more time as well vs the 5P due to more components involved. I don't know how much the DIY training time compares to the two systems.

So there's no point to do PowerPro+18kpv if the goal is on-grid ROI.

 

[1201]

PowerPro+18kpv is $10K pre tax.

If you DIY in the Enphase 5P it's $4K pre tax on Renvu's eBay storefront, which is a very good ROI on top of also staying within the ecosystem. So presumably one can even drive up to CED Greentech or Renvu local branch with a truck and load it up for low delivered cost.

I would expect PowerPro+18kpv to have a higher install cost for non-DIY. And for DIY it would probably cost more time as well vs the 5P due to more components involved. I don't know how much the DIY training time compares to the two systems.

So there's no point to do PowerPro+18kpv if the goal is on-grid ROI.

Does 5p mean 5kwh? What's that going to do?

 

[zanydroid]

Does 5p mean 5kwh? What's that going to do?

It’s the cheapest grid tie compliant ESS. This is an AC battery so it has both inverter and battery inside it.

OP will have to math out the capability / cost reduction that it can yield via self consumption or forced export. It is not a good idea to just assume that all $1500/year or whatever it was, will be offset by this investment.

 

[1201]

It’s the cheapest grid tie compliant ESS. This is an AC battery so it has both inverter and battery inside it.

OP will have to math out the capability / cost reduction that it can yield via self consumption or forced export. It is not a good idea to just assume that all $1500/year or whatever it was, will be offset by this investment.

Cheapest means nothing if you don't actually save anything.
I appreciate you looking at cost effective options but we need to find options that will get him through peak hours and 5kw ain't gonna cut it

 

[Hedges]

Look at load management first.

 

[zanydroid]

Cheapest means nothing if you don't actually save anything

How would that happen?

There were multiple people here in similar POCO/rate plans within same state that mathed out savings for their personal situation. It’s just not necessarily worth the cost of money when invested. The main thing I’m not sure about is whether Enphase supports forced exports (I looked at it a while back and I don’t remember the answer). Self consume definitely works