Adding storage to my Enphase system

I guess I don't understand all this math yet.
I have 18 400 w panels =7200w
My Enlighten app say 5.3kW.
Is that good or bad?
 
7200W (STC) is measurement based on flashing panels with one standard sun, 1000W/m^2, while panel is at 25 degrees C.

NOCT, reduced light and increased temperature, or PTC, elevated temperature and wind, give closer to actual output under most conditions.

75% to 85% of STC is reasonable most of the time.

Monitor over time, if you see a trend that isn't related to seasonal or weather variations it could indicate degradation.
I found one of two strings lower than the other after many years, and some panels were bad.

"Enlighten" - what is wattage rating of micro inverter? Multiply by quantity, what is max AC wattage rating?
 
1.21A x 240V = 290W microinverter.
18 x 290W = 5227W
Maybe it goes a bit higher when line voltage is higher.

If you get a graph of production for the day, you can estimate where the curve would have been if not clipped.
Given the relative cost of PV panels vs. inverters these days, it is reasonable (cost effective) to overpanel the inverter and allow some clipping. Depending on the incremental cost of higher wattage inverter.
 
Solar is doing much better today. My 7x 230W used panels from Santansolar were producing 1500W at some point today. Is that even possible?
 
It's so nice to see real sunlight again.
It's just now 2 pm and my Enphase panels have already produced 16 KWHs. The 4,800 watt array peaked at about 3,600 watts.
Add to that, the DC system is also rocking. The battery voltage hit the 56.5 volt absorb limit in the XW-Pro by 11:40 am. And it's getting close to the Victron DC controller limit of 57.6 volts just after 2 pm.

The new Version 2.04 firmware is working perfectly, and the graphs look much better. It is reporting the real values, not some fake smoothing. Here is yesterday. It was not quite sunny all day, but still did well.

XW-Batt-02-09-24.JPG
Over 3 hours of energy export from when the XW stopped charging until the battery began discharging at 4 pm. The little discharged spike in there were from heavy clouds going over. We don't have any of that today. On top of the 45 amps from the XW, the DC system also hit over 24 amps. The total charge rate hit over 69 amps. That is still under 0.1C so no issue for my battery bank. 56.5 volts x 69 amps = 3,900 watts going in to the battery, while the solar is powering everything in the house as well.

As much as I would like more solar panels, this does meet my needs now. But do I have enough left over to charge an EV?
 
Another rocking day on Feb 10th. Here is what the Enphase panels did.
Enphase-02-10-24.JPG
This is my first day of the year breaking past 20 KWHs. That is 4.1875 sun hours.
The Victron controller on my cheap DC panels did really well too.
IMG_4564.PNG IMG_4563.PNG

The day in question is the second bar where the Victron controller did go into float mode. So it did curtail off some production. The 11th was actually down a little on production so the battery didn't quite top out, but it came real close. That's how the DC system made a little more. But back to the 10th, here was the battery trace from the XW.
XW-Batt-02-10-24.JPG
The house easily ran off the battery all night. It never fell below 52 volts as the sun came up. The charge rate was very quick. The XW hit 46 amps and the Victron hit about 25 amps, so figure it peaked around 70 amps going into the battery bank. The XW went into "no float" before noon. The loss of that near 40 amps of charge current now does show the voltage dipping back a bit with the new software. But then, the new software also shows the voltage just climbing from there with the 25 amps still coming in from the DC system. It looks like the Victron controller went into float mode for nearly an hour, keeping the battery full as the Enphase system was no longer making enough power to supply all the loads in the house. As the voltage began to drop, the Victron went right back into bulk charge and was pushing in all the current it could, but the sun is way down by then and the battery voltage kept dropping. Most of the small negative current spies are from the furnace kicking on 4 times per hour to keep the house warm. The wider 30+ minute gaps are the refrigerator compressor cycling. The 2 long sharp current spike in the evening are the microwave oven. When those cycling loads are all off, my house is still pulling 10 amps from the battery.

Here is what the So Cal Edison power meter saw.
SCE-02-10-24.JPG
Just as before, I was exporting 20 to 60 watts all day, until the battery was full. While the XW just sat in "No Float", the Enphase inverters just kept exporting their extra power. It held an average of over 2,800 watts for the whole noon hour. And that is just the energy beyond what it is taking to run my house off of the Enphase array as well. They show the "Average Consumption" at -0.36 KW or a running load of 360 watts for the full 24 hours. That works out to something like 8.6 KWHs that I exported to the grid for credit that day.

We have a few more good days coming through soon. But then rain again next weekend.
 
Southern California Edison has completely rearranged their web site. It's going to take me a few days to figure out here everything got moved to.

One new line I found funny. "Last payment $ 0.25 on Feb. 23, 2023"

Yup, that was the last thing I paid So Cal Edison for electricity. I have been running off solar and saved credits ever since.

Along with the new web site lay out comes new rates.
Winter_SCE_rates.JPG Summer_SCE_rates.JPG

OUCH!! Sure glad I am not really using any electricity from them. That summer weekday peak rate of $0.60 is crazy. I may have ot make a few adjustments and push some export to that time to get more credit. As it is now, 98% of my export is happening at "Super Off-Peak" or "Off-Peak" $0.36 in Winter and $0.37 in Summer.

On the flip side, my battery system will pay off even faster now.
 
Wow!

You have rates as LOW as $0.36/kWh??



Faster?
Is the spread between on and off peak larger now?
$0.23 summer weekday, $0.12 summer weekend.

How much do your batteries cost you, and what is round-trip efficiency?
 
One new line I found funny. "Last payment $ 0.25 on Feb. 23, 2023"
Can you make it an entire year? Or do you owe them another quarter?

I have PGE for both electric and gas. So my numbers aren't quite as impressive. My true up was in December, those credits covered the gas bill most of the way through Feb. My current bill is $6
 
Wow!

You have rates as LOW as $0.36/kWh??



Faster?
Is the spread between on and off peak larger now?
$0.23 summer weekday, $0.12 summer weekend.

How much do your batteries cost you, and what is round-trip efficiency?
I am doing less "round trip" now as the DC system is supplying about 70% of the battery power for use during the night, including the "Peak" and "Mid Peak" rates. I am back to exporting more and still covering my whole day unless the weather is bad. The time shifting is still saving about the same amount, but the overall savings from not buying power has increased. Without the battery (or the DC panels), I would be exporting over 10 KWHs and buying almost all of the back at the higher rate. With the battery (and the DC panels) I am still exporting 8 KWHs at the cheap rate, but also still exporting a small amount the rest of the day, including a bit at the peak rate time.

I know this is not totally fair math, but, my average electrical consumption, it very close to 1 KW all day long. It goes up and down a bit, but in total, I end up very close to 24 KWHs a day. Today, my system produced 18.9 KWHs from the Enphase micros. 6.2 KWHs of that got charged into the battery. Another 7.7 KWHs from the Victron DC setup went into the battery. That's 26.6 KWH's produced. At the end of the day, I will have pulled over 13 KWHs back out of the battery, but some of it was from yesterdays stored up this morning. Back without the DC panels, I would lose 1 KWH to the round trip charge/discharge. Now it looks like I an losing a little more. That seems odd as the DC charging is way more efficient as it only inverts once.

So far this year, the XW-Pro charged the batteries with 321.8 KWHs. The Victron did 250 KWHs. Add those up and 571.8 KWHs went into the battery and the XW-Pro inverted 497.5 KWHs back out of the battery. By those numbers, I lost 74 KWHs over 46 days. That works out to an average of 1.6 KWHs a day being lost. That looks like only 87% efficiency. It should be better than that, but I will go with what the XW is reporting for power in and out from the battery.

Even if I exported all of my solar over production (4,800 watts of panels on Enphase AND the 2,000 watts of DC panels) , at the cheap rate I get ($0.36 x 18.6 KWHs) = $6.70 credit.
But then I use 4 pm to 9 pm... 5 KWHs at $0.53 = $2.65, and then 9 pm to 8 am 11 KWHs x $0.40 = $4.40
$6.70 in credit super off peak - $2.65 peak and $4.40 off peak = -$0.35 that I would get charged for the day. And before I had the batteries, I had 2,000 watts less of solar panels. I was not exporting as much so I was getting hit even harder.

Using the battery I never use any power coming in from the grid. I exported just 6 KWHs during Super Off Peak at $0.36 = a credit of $2.16 for the same day. That is a savings to me of about $2.50 for each day just because of the battery. That is what justifies the battery cost for me. Time shifting the power not only cut my total bill by a chunk, it gave me backup power during a grid outage for free.

If I didn't have solar at all, and I used the same constant 1 KW all day long, I would have to pay about 8 KWH x $0.36 = $2.88 from 8 am to 4 pm then 5 KWHs at $0.53 = $2.65 from 4 pm to 9 pm and finally 11 KWHs at $0.40 = $4.40 from 9 pm back to 8 am again.

That is a total of $9.93 a day for 24 KWHs for an average of $0.41375 per KWH. $9.93 x 365 days = $3,624.45 a year to run my basic base load at my house. And last year I paid NOTHING and have a $179 credit remaining. If I save $3,500 a year for 8 years, it pays for everything. The original Enphase install, the XW-Pro inverter, the 36 KWHs of batteries, the 2 solar charge controllers, etc.

This is not a perfect calculation, and it varies greatly from day to day, but this is a pretty good average of where I end up after a full year. There will be days I export a lot more, and days I have to consume, but this is where I have been falling for the last 11 months.
 
Can you make it an entire year? Or do you owe them another quarter?

I have PGE for both electric and gas. So my numbers aren't quite as impressive. My true up was in December, those credits covered the gas bill most of the way through Feb. My current bill is $6
My gas bill for this winter is way up and my electric savings is not coving that, but on electric only, I will have a Feb. bill of about $30 that will go against my $179 credit I still have. In March, I expect to not eat any more credit. April and May, I will rack up a chunk of credit. I think I can do better than net zero now, with just 6,800 watts of panels.

Of course, that will change when my son is living with me again, and if (when) I get an EV.

I am tempted by an amazing offer on a Mach E California Route 1 Edition. It has the dual motor all wheel drive of the GT, but it is detuned a bit and runs on skinnier tires. It still does 0-60 in just 4.8 seconds with 346 HP, but it manages 312 miles of range where the GT can only get 260 from the same 91 KWH battery pack. 52 miles is a huge difference. That is 3.42 miles per KWH vs just 2.86 M/KWH in the GT. That is almost a 20% increase in range. Is it worth the range loss to get 0-60 in 3.5 seconds with 480 HP?

Going with the 3.42 miles per KWH figure. How does it compare to my C-Max getting 42 MPG.

I get the best range running 89 mid grade. I just filled up at a Shell for $4.999 per gallon / 42 = 12 cents per mile.

If I grid charge the Mach E Route 1 overnight at $0.40 per KWH / 3.42 miles = 12 cents per mile. Hmmmm It's a wash. 11.9 vs 11.7 if you want to get picky. I'm going to need a few more solar panels.
 
They cut the month a day short and billed just 29 days on the new system. The charge off of my credit was just $5.47 for the taxes and NBC's. That leaves my remaining credit at just under $170 now. The energy used was a fair chunk less than previous years. The energy used took $16.13 off of my energy credit. That leaves my plan year energy credit down to just $13.45 at 4 months in. I have exported 78 KWHs more than I have used so far. Here are the new style graphs. Total month usage.

SCE-Jan-Feb-2024.JPG
And this is what the Enphase production looked like over the same time frame.
EnphaseJan-Feb24.JPG

And here is another new graph that SCE added.
SCE-UsageBreakdown-Jan-Feb-24.JPG
All the power I imported was "Off Peak" not "Super Off Peak" But to shift that, I would need more battery and programming to save only $0.04 more per KWH. It's not worth it.

Here was my last day they put up the data for.
SCE-02-14-24.JPG

This is what the battery did on that same day.
XW-Batt-02-14-24.JPG
I have it tuned great for good weather, but I need to find a better way to deal with the bad days.
 
My gas bill for this winter is way up and my electric savings is not coving that, but on electric only, I will have a Feb. bill of about $30 that will go against my $179 credit I still have. In March, I expect to not eat any more credit. April and May, I will rack up a chunk of credit. I think I can do better than net zero now, with just 6,800 watts of panels.

Of course, that will change when my son is living with me again, and if (when) I get an EV.

I am tempted by an amazing offer on a Mach E California Route 1 Edition. It has the dual motor all wheel drive of the GT, but it is detuned a bit and runs on skinnier tires. It still does 0-60 in just 4.8 seconds with 346 HP, but it manages 312 miles of range where the GT can only get 260 from the same 91 KWH battery pack. 52 miles is a huge difference.
Yeah, huge difference!
That is 3.42 miles per KWH vs just 2.86 M/KWH in the GT. That is almost a 20% increase in range. Is it worth the range loss to get 0-60 in 3.5 seconds with 480 HP?
The 19 year old in me says it's an easy decision.
The rest of me would go for the range.
Going with the 3.42 miles per KWH figure. How does it compare to my C-Max getting 42 MPG.
Never going to the gas station is pretty nice.
I get the best range running 89 mid grade. I just filled up at a Shell for $4.999 per gallon / 42 = 12 cents per mile.

If I grid charge the Mach E Route 1 overnight at $0.40 per KWH / 3.42 miles = 12 cents per mile. Hmmmm It's a wash. 11.9 vs 11.7 if you want to get picky. I'm going to need a few more solar panels.
Does SCE have an EV rate? PGE does, it has lower overnight rate as a trade off for higher peak rates.

What if you add more DC panels to run the home loads and charge the EV from your Enpha system during the day?
 
Does SCE have an EV rate? PGE does, it has lower overnight rate as a trade off for higher peak rates.

What if you add more DC panels to run the home loads and charge the EV from your Enpha system during the day?
The SCE EV rate includes a higher fixed fee as well. Last I looked it was almost $30 a month if you use no electricity, but the overnight rate dropped under 20 cents. It may be higher now with the recent raise. Last time I ran the numbers, it would cost me more than the plan I am on.

That would probably be my plan, add more DC panels. I have a space where I could add 4 more "60 cell" size panels on the end of my lower roof Enphase array. My existing panels in those arrays are 300 watts each at 19% efficient. More modern panels that size are more like 375 watts and 22%. That would add about 1,500 watts to the DC system. 4 sun hours would bring another 6 KWHs. Not enough to cover my daily mileage in an EV, but it would sure help. About 4 days a week, my car is home while the sun is shining. I can try to make it charge from the extra instead of exporting it. The PLC has plenty of memory left to add another control loop. Just need an EVSE I can control with modbus.
 
The SCE EV rate includes a higher fixed fee as well. Last I looked it was almost $30 a month if you use no electricity, but the overnight rate dropped under 20 cents. It may be higher now with the recent raise. Last time I ran the numbers, it would cost me more than the plan I am on.
Yuck, nevermind. No thanks. I forgot about the fixed monthly cost, I think PGE has that too.
That would probably be my plan, add more DC panels. I have a space where I could add 4 more "60 cell" size panels on the end of my lower roof Enphase array. My existing panels in those arrays are 300 watts each at 19% efficient. More modern panels that size are more like 375 watts and 22%. That would add about 1,500 watts to the DC system. 4 sun hours would bring another 6 KWHs.
Do you have room for a 3rd row on the flat roof with the 100/200 watt panels?
Not enough to cover my daily mileage in an EV, but it would sure help. About 4 days a week, my car is home while the sun is shining. I can try to make it charge from the extra instead of exporting it. The PLC has plenty of memory left to add another control loop. Just need an EVSE I can control with modbus.
OpenEVSE is controlled by MQTT, but I've never seen an EVSE with Modbus.
 
I've never seen an EVSE with Modbus.
It seems there are some, but the modbus part is hidden from users.
 
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