Adding storage to my Enphase system

[GXMnow]

Here is my second day of manually forcing my grid charging to happen during "Super Off Peak" electric rates.

I will start with the Enphase system production.

As you can see, the production SUCKS!. Peak power was down over 500 watts, and it was down 12% from last year. Most of the drop is just due to the panels being stupid hot, but the sky is also this hazy goo which is a big part of the reason it is so hot. It is an actual greenhouse holding in the heat. In the evening, some of the haze cleared, and the panels that became shaded after 3 pm also were able to cool a little, so production after 4 pm actually matched, or even beat, last year. Total production for the day though was 18.8 KWHs or just 87% of last years 21.2 KWHs. That is 2.4 KWHs of lost production.

Most "Grid Tied" PV Solar power systems would have still had the lowest consumption and some export 11 am to 2 pm. If they are going to skew the rates and make power cheap at that time, I can do this....


I turned off the PLC and adjusted the charging power 4 times, and then turned the PLC back on after 1 pm when the A/C started having to cycle to deal with the heat. The plan was to keep the import rate close to 1,000 watts. And I may try to program that into the PLC, but I need to then put an option switch in it as I only want to do that on these stupid hot days with reduced production. I didn't quite get the battery up to 56 volts, so it was only up to about 75% SoC. But you can see that at midnight, I was basically breaking even with the battery hitting the same level as it started the day. And here is what SCE reported for my usage that day.

The PLC and XW-Pro setting are still blocking power back to the main panel starting at 6 am. So I did end up using 0.2 KWHs of "Off Peak" power from 6 to 8 am. But then I started charging up the battery. I ramped it up along with increasing solar and I got it pretty close to my 1,000 watt target a few times. 5.3 KWHs were pulled from th grid in the "Super Off Peak" time. And then I had just my tiny 60 watts of export from 4 pm to 9 pm. Even with the A/C running a lot, the battery was able to cover it and you see no consumption during this "Mid Peak" time.

I probably pulled that 5.3 KWHs from my immediate neighbors 10 KW solar array. so SCE should be thanking me for taking that so it didn't have to go back through their transformer and stress the system.

I have lived here for almost 21 years, and we have never had weather like this in October before. Sure, we had "Christmas in the 80's" but this is closing in on "Halloween in the 100's". It hit 104 today, and is down to JUST 97 now at 5:15 pm. They predict hitting 101 again tomorrow and still a full week with the high of 89 to 95 after that. I sure hope this moisture in the air calms a bit so more sunlight can get to the solar panels. They are a little dusty, but it should not be down this much. And I am seeing the same drop on the DC array as well. Production there is also down to under 8 KWHs a day. And peak power was also off to under 1,300 watts instead of the normal 1,550 for that array.

 

[dougbert]

here in Salt Lake City area, we have had the FIRST 92 deg F in October EVER
latest 100 F in sept

12 degrees above average for the next 5 days

 

[GXMnow]

Another SCE billing month has ended.
October started the winter billing. So half my bill is at Summer rates and the other half is at Winter rates.

They "adjusted" the rates again. This one was sneaky. The actual rates didn't really change, but the dropped the "baseline credit" by on cent which effectively makes every rate 1 cent more.
With the crazy October heat wave, I still managed to do pretty well, but not as good as the previous 2 years. I still managed to over produce by only 29 KWHs at the end of the month. That gave me a credit of $9.55 on the energy side. That is almost 33 cents per KWH since I did export a chunk of it at the peak rate.

On the taxes and fees side, I was at $3.18 but the minimum charge is $10.50 so they just added $7.52 as "Balance of minimum charges". But then they also issued a "California Climate Credit". I have no idea how it is calculated, but it is a refund/credit they give to the customers. I am certainly not going to complain. This year it is $86 added to my credit balance. Even with the $10.50 minimum charge, my credit goes up by $75.50 and I am back to nearly $300 again.

Here is what the Enphase system produced for this billing period.

It is very easy to see we are well past summer equinox as each day is less and less production. It won't start going back up until December. I may get a little step up in I rinse off the panels again. But a few days did beat last year, so I know they are not that bad.

The DC Victron system is looking the same, just divide it by about 2.4 as it is 2 KW of panels vs 4.8 KW of panels. It looks like the Victron produce about 200 KWHs in the same time frame. Yesterday was a nice clear sky with cool air and the Victron produced 7.98 KWHs and the Enphase produced 19.1 KWHs. That is right on the 2.4 : 1 ratio between the systems. The Victron DC did a fraction of a percent better. Most likely due to the palm tree shadows hitting the Enphase system worse.

 

[GXMnow]

For the last 6 days, my system has just plain "worked". It has net exported each day, from 0.5 to 5.0 KWHs each day. The average so far for this billing cycle is at -3 KWHs a day. And this totally points out why I needed the extra solar panels. The DC coupled panels are producing just about 7 KWHs a day. Without them, I would have been net using over 3 KWHs a day instead of exporting that much. Those cheap Amazon panels made a huge difference.

Now I want to build my 3,000 watt pergola in the back yard. I just need to figure out how I am going to get the wiring back to my garage on the opposite corner of my property.

 

[Solarisium]

. As long as I stay under my "baseline allocation" I do get a 10 cent discount…

... I have no idea how much my "baseline allowance" is, but I have not hit it since I went solar. My guess is it has to be over 500 KWHs a month. .

There is no baseline in TOU plans.
The reason you dont see $.60 in your bill, is that its is broken down into generation, delivery and basic charges. in total it should be equal to your rate.

Baseline applies to tiered plans where over a defined amount of energy your rate goes up a bit.

 

[GXMnow]

Here is a screen shot of my "Tracked Charges" from my last SCE bill.


The first two lines are my "Baseline Allowance" "credit". Last year it was a tick over 10 cents per KWH, the Summer rate dropped it to 9.591 cents, and the new Winter rate dropped it more to 9.379 cents. When I net export, it turns into a charge against my credit. It took me a minute to understand that as it is just adjusting my rate per KWH. So when I export, I also am exporting at the discounted rate.

The reason there are two on this bill is because the first one is the Summer rate, and the second is the Winter rate. Due to my billing date being in the middle of the month, I get this split bill twice a year when the rates change. This was an odd ball one in that Summer rate was on a net export of energy while the Winter rate was on a net consumption of energy. It's odd that it did that. I have tried to look up my baseline allocation, but the SCE site just runs me in circles.

I imported 52 KWHs at Winter rate and exported 81 KWHs on Summer rate for this billing month. If it was all at the same rate, it would have just shown as -29 KWHs total. That is how it shows in the info box. Next month will be all on the Winter rates. Obviously they calculate the credit for each different rate. This is my first bill for the new "billing year" so the balance started back at zero. For now, it shows a credit of $9.55 for the 29 KWHs I exported. That works out to $0.3293 per KWH average for the energy I net exported.

 

[Solarisium]

I see that line in my bill too:
I’m not sure if that actually means “baseline”.
This is unnecessarily complicated!

Apparently i generated a surplus of 202 kwh under summer rate, and a surplus of 93 kwh under winter rate.
SCE charged me $19.37 + $8.72 for delivering my export to their grid !

Is that correct?!

 

[GXMnow]

I see that line in my bill too:
I’m not sure if that actually means “baseline”.
This is unnecessarily complicated!

Apparently i generated a surplus of 202 kwh under summer rate, and a surplus of 93 kwh under winter rate.
SCE charged me $19.37 + $8.72 for delivering my export to their grid !

Is that correct?!


View attachment 252247

Not really. What they did was they reduced your credit by that amount to bring your credit rate down to the same discounted rate that they would have billed you. When I first saw the "Negative" credit on my bill, I also kind of freaked out until I did the math myself. In your summary on the right, you exported a net of 295 KWHs total for the month, and they gave you a credit of $72.48 That works out to $72.84 / 295 = $0.2457 per kilowatt hour. Most of your export must have been between 8 am and 4 pm.

Do you have a battery system to time shift production? I export very little as I have my battery charge from the extra at that time of day, exporting only about 200 watts. When my battery does get full, I do end up exporting a bit more, and it can roll into the higher rate time after 4 pm. That is how I end up with a high credit per KWH. And then I use almost no SCE power from 4 pm to 9 pm as I run off the battery. This is why my export credit is quite small. But then I also have very low usage which greatly drops the NBCs.

I went solar 5 years ago, and things have certainly changed since then. I got 4 quotes from solar companies back then, and all of them wanted to over produce at noon to cover the full day. But they never even mentioned the "Time of Use" billing. They did all the math based on my old tiered billing rates so they were horribly wrong. But I didn't know any better. I went with a smaller system as I just wanted to cover my extra summer load when my bills would go over $300 a month. But my first year billing was a mess. While the solar panels did cover 70% of my energy use for the year, I still ended up having to pay over 70% of my previous years total. And since they put me on annual true up, I had no idea until the year end came. I was getting bills from $10 to $25 and figured, wow, I am saving a ton with the solar. I didn't read the tracked charges part as I never saw that before and it was never explained. October came and I got a bill for $1,500 for the energy I used all year. I would much rather have been paying $125 a month and I managed to get my billing changed to monthly for year 2. And I started looking into the battery because of the time of use billing. At first I just started charging 10 KWHs into a battery while the sun was up, and then discharging that 10 KWHs between 4 pm and 9 pm. That alone cut my remaining power bill in half. Even though I was losing 1 KWH a day to the losses in the charging and inverting. Under NEM 2.0 a battery helps a lot. Under NEM 3.0 you NEED a battery!

 

[GXMnow]

Another billing month has ended. My total bill ended up being about $11. It took almost $9 off of my credit for the taxes and fees, and a bit over $2 off my energy net credit. Total net usage was just 7 KWHs for the month. Last year I had a credit this month, so I did a bit worse. We did have a few days of bad weather And each weekend, my son was gaming on his PC sucking up nearly 1,000 watts for many hours. Take a look at this.

Can you guess when my son had his gaming marathons?

The time does not line up exactly. The system tried to support it off the battery, but then it would run too low and it would need to grid charge the next morning. I still made sure it only charged at Off Peak or Super Off Peak. Production was also down a bit from last year due to the weather and the palm trees being 5 feet taller.

 

[GXMnow]

I just rinsed off my solar panels again. It is already past my solar non, so a bit tough to tell exactly how much it improved it until tomorrow, but the
DC system shows nearly a 15% power increase after the rinse off. It peaked to 20%, but that is also the cooling effect of the water, the power then drops back down as they warm back up in the sun. The Enphase app only reports every 15 minutes, and the power level is dropping past noon and the palm tree shadow is moving in as well. The live power meter reading is showing 2.1 KW at 1:15 pm. That is well ahead of yesterday's power and very close to last year when the palm tree was much shorter too. Overall, I would say it probably improved total system production close to 10%. The DC panels are at a flatter angle, so more dust was settled on them compared to the higher tilt of the AC panels on the sloped roof.

 

[GXMnow]

Yes, my panels were quite dirty. Here is the graph so far today.

The power is tracking 200 to 300 watts above yesterday before the panel rinse. That is nearly a 10% power increase. The DC system looks like it may be doing even better, but the Victron App does not do a graph like this. But comparing the data, the DC panels are putting out a solid 10% better than yesterday.

 

[GXMnow]

We are still a couple weeks from the winter solstice, so I was not expecting to see this.

We only had a little rain the last few days, but today was clear, and the solar panels did way better than they have been for the last 2-3 weeks, and even out did this time last year by a chunk as well. The DC system also did better than it has in over a week. I didn't think we had enough rain to really clean the panels better than I did with the hose. Maybe the "Atmospheric River" weather we had also cleaned the air and more sun is making it through?? Whatever the reason, I like it. The Winter Solstice is officially Dec, 21 this year, so over 3 weeks before the days start getting longer again.

 

[Siamac]

How's your production now?

 

[GXMnow]

I actually started typing a reply to this when my SSD Boot Drive decided to die on me. Things have been a little busy, and I thought I got that sent, but, nope, it must have gotten lost in my crash, and I just noticed that my reply is not here.

Late December production is never great, and this year, it is looking a little worse than last year on the good days. But we have had more "good days". Last year, I had 6 days in a row that were just 3 to 10 KWHs a day on the Enphase system. So far, only 3 days have been below 10 KWH's this December. I can't complain about that. And my DC system is doing pretty well too. Production is in line with what I expect for just 2,000 was of panels. My average is just over 5 KWHs a day, most days a bit more, and those same three days a bit less. The shadows are a biut worse than last year due to trees growing.

My new system addition should help a lot. I hope to get it online by mid January. I am starting a new thread on my Solar Pergola buld here...

Thread 'My solar Pergola build'

Dec 23, 2024

This is the "Show and Tell" area, so I am starting a new thread about my next project. The plan here is to add nearly 4,000 watts of panels to my system to get close to 10 KW of total PV panels online. I have a HUGE thread here already from when I added a Schneider XW-Pro to add self consumption time shifting and backup power to my Enphase grid tied system. That thread is out to over 1,900 posts. Here is the link if you want to skim through that.


After adding the XW-Pro and 18 KWHs of Chevy Bolt batteries...

• GXMnow
• Replies: 109
• Forum: Show and Tell

• 
• 

 

[GXMnow]

I also just ended another monthly billing period. This was interesting to see. Evidently, So Cal Edison figured that they over billed me the last 2 months. I am certainly not going to argue. They gave me an extra $7.43 credit as a "Billing Adjustment" from 9/17 to 11/14, my previous 2 billing periods.

This month, 11/15 to 12/15, I did fall short on energy production. The "New Charges" totaled $43.74 for 143 KWHs consumed from the grid and all the NBC's etc. That works back to an average energy cost of 30.5 cents per KWH after all the taxes etc. Yeh, energy is expensive here, and almost all of my consumption is at the lowest time of use rate. This is why I am still dragging my feet about going EV. My current hybrid is still getting 42 MPG at $4 per gallon or 9.5 cents per mile. A good EV gets 3.5 miles per KWH. 0.305 / 3.5 = 8.7 cents per mile. Yeah, it is a little cheaper, but not a huge amount if I have to charge it from the grid, which right now, I would not have a choice. Maybe once my Solar Pergola is up, I will have the extra energy I need most of the year. That is part of the plan.

I did opt for monthly billing, and my energy credit has zeroed out, so they took this charge off of my account credit and I now have no energy banked as I just started a new billing year. But I do still have a bit over $200 USD in credit for paying off these charges from my over production the last 2 years, even though they bought my energy credits at just 2.5 cents per KWH. Then they sold the energy I exported to them to my neighbors at over 30 cents. SCE got a pretty good deal.

 

[GXMnow]

Now that we are past the winter solstice, I am already seeing the production starting to increase a bit.

I did not use any grid charging yesterday, but I did end the day a little lower SoC that I stated. So, I did trigger the XW to charge at just a 5% rate for a couple hours early this morning as I didn't trust the weather forecast. But so far, the sun is out in force. I still doubt it will top out the batteries, but they have only been reaching under 70% for 2 months, they need a good solid charge.

according to the XW-Pro "Energy" page, it says I have discharge (inverted) 5 Mega Watthours from the battery this past year. I wish it would put a decimal point on that. But since the other displays do show a decimal such as 2.4 MWHs charged into the batteries, I can say it must be between 4.9 and 5.1 MWHs. If we go by the math that the BMS uses to calculate cycles, we divide that by the rated capacity. 5,000 KWHs / 36 KWHs = 139 full cycles in a year. And that 2.4 MWHs that the XW-Pro charged in also works out, because the Victron charge controller also pushed 2,743 KWHs into the battery. Add those and we get a little over 5.1 MWHs went into the battery. Round trip efficiency is a bit under 98%. I'm good with that. LG rates these cells for over 3,000 20% to 80% cycles while charging and discharging at a full 1C rate. 3,000 / 139 = 21.5 years. I doubt I will get that, but it's nice to know my 10 year hope is well in reach.

I am finishing this as the sun is setting. This has been the best production day in over 2 weeks. Hit 14.6 KWHs from the Enphase system and almost got to 6 KWHs from the Victron system. The battery got to over 80% SoC, but I did cheat a bit with a couple house of grid charging. Tomorrow's forecast is saying partly cloudy all day. So I expect it to fall a bit short, but with the battery this high, I will let it go and see where it ends up by 9 PM to see if I need to grid charge tomorrow night.

Too bad I don't have the new array up yet.

 

[GXMnow]

14.9 KWHs today on the Enphase system. We are definitely on the way up. The forecast was "Partly Cloudy" but it obviously wasn't. Power peaked over 2,900 watts. That is 60% of STC rating. And also 3.1 sun hours. Not great, but decent.

The panels on the DC system are too flat, especially this time of year, so this is not great, but it is improving.

Not sure what happened at noon, when it should have been at peak power. There is a bit of a dip. The odd dip in the voltage curve is the XW-Pro shutting off charging as it did hit it's absorb voltage limit. It absorbs for just 15 minutes as the Victron keeps pulling the voltage up. 5.27 KWHs is only 2.64 sun hours. A fair bit off of the 3.1 that the AC system did. And peak power only hitting 1,100 watts is also weak at 55%. But with the panel angle issue, I guess that is about right.

I was really hoping to hit 3 MWHs from the DC system, but with just 1 day to go, it's not going to happen. If tomorrow is really good, it might hit 2.76 MWHs. The Enphase system is also down a bit from the hoped for 8 MWHs at just 7.2 this year. But that actually matched last year as well. That is 1,500 sun hours for the year. The Victron DC system did a little worse at 1,380 sun hours. But in the summer, it did drop to float charge quite a bit, so it actually could have done better.

 

[GXMnow]

I had to post this one...

I decided to take a look how I was doing on grid consumption. 2 days ago, I knew there was enough in the battery, so I just let the system go and do it's thing. Here is what happens when I have enough energy, but the battery does not get full.


At first glance, it looks like a fair bit of power both consumed and exported, until you look at the scale on the left. My maximum energy usage only hit an average of 230 watts for the 9 am hour. We used the microwave a few times. The rest of the time, we used less than 130 watts from the grid. And the export side is even less. Export peaked at just 110 watts in the 11 am hour. Average it over time and I only need a 1 amp main breaker.

Here is what the XW-Pro battery had to do to run the house like that.

The battery did nd the day about 1 volt below where it started, so the solar just didn't quite make enough. The battery charge and discharge current topped out at a peak of about 40 amps in both directions. Average it to 53 volts and that is over 2,100 watts going either way. And in fact, the charge direction was a fair bit more because this does not report any of the energy coming from the Victron DC system. On that day, it hit a peak of just about 1,000 watts, just shy of 20 amps. And it pushed 4.77 KWHs into the battery. Add that in, and where the battery voltage slope is the steepest, it was probably getting close to 60 amps of charge current all from solar, after running all the loads in the house. And that is still just my existing 6,800 watts. My new pergola array will add another 3,600 watts of panels to the mix. That will be 10,400 watts of solar panels.

 

[GXMnow]

I just had to post this little update.

I have had the 3 new panels leaning on my wall pushing some power into my battery for 3 full days now. Take a look at my SCE usage for this billing month.

The weather has been odd, and we had a lot of bad days, but on the best days before Dec 30th we basically just broke even. But then look at the last 3 days. Net exporting almost 2 KWHs each day. The new panels made over 3 KWHs each day. Without them, those 3 day would have ben net consumption days. Here is the hourly chart for yesterday.

The small amount of import from 6 am to 8 am is programmed in. If I don't pull any power from the grid for a few days, So Cal Edison thinks something must be wrong. So, at 6 am, I stop the XW-Pro from selling to grid which means any load in my main panel has to come from grid until the sun comes up. We typically have very little load at that time, and it keeps SCE happy. Once the sun is up, the PLC commands the charge current to use as much as it can to charge the battery, while allowing about 80 to 120 watts to go out to the grid. This ensures I am only charging on solar power and getting a little credit as well.

With the extra solar panels, the XW-Pro hit its bulk charge limit at about 1 pm. As the charge current tapers off, the extra AC coupled Enphase solar power just ends up exporting. Due to the low shadows this time of year, the energy from the lower roof tanks after 2 pm. So it only exports around 1 KW for just over an hour.

The two DC charge controller continue to charge the battery pulling as much energy as they can until the battery voltage hits 57.6 volts. It has not gotten there yet, and the DC systems are both basically done about 4:30 PM this time of year. The XW-Pro is then commanded on how much to export to the main panel to cover the loads again, all the way to 6 am the next morning again.

Here is the XW battery summary for the same day.

We ran laundry, and the dishwasher, as well as used the microwave several times which causes all those big downward current spikes. But the big takeaway here is that we ended the day with the battery above where we started the day, and WOW look at how fast the battery was charging up. This is actually less than a 0.15 C rate, but that is still a lot of power going in to make it climb like that. Between the XW charge current and the two DC charge controllers, I think it hit over 80 amps of charge current.

It's going to get really wild when I have 7 more 400 watt panels connected.

 

[GXMnow]

The trend continues.

Even with a semi cloudy day, and my son gaming, I have net exported every day since I put the 3 new panels into the system.

That shows 6 days in a row, today is day 7, and I am already exporting as the battery hit bulk limit at 12:40 PM. I'm pushing 1,600 watts to the grid right now. If the sun stays out, I may even have the DC systems drop to Absorb.

With 7 more panels going online soon, I will be solidly topped up and exporting pretty much every day without worry... Until I get an EV.

 

[dougbert]

really nice. fun too

 

[GXMnow]

I just got woken up at 3:30 am by a robo call from So Cal Edison.

"My power is likely to be shut off within the next 4 hours and could be out up to 3 days due to the wind and fire threat conditions in my area."

My battery was full charged yesterday, but it has been running the house since sunset. It is down to 54.3 volts. That works out to about 75% SoC. It probably would be fine with the 3 extra panels, but to be on the safe side, I just flipped the system to grid charge at 20% (28 amps) as long as the grid says up. If the power is on for another 3 hours, that is about 4.5 KWHs into the battery before the sun comes up. That should raise my SoC by about 12% or so.

Looks like I may be having an extended off grid test.

 

[GXMnow]

8 am and grid power is still no. The battery bank is at 85%+ and it was charging from grid power with no interruption. I am guessing the power cut is a bit further south. There is another fire that started last night in the Newhall pass which is less than 10 miles from my house. It is mostly in a non-populated area, but they are issuing some evacuation recommendations, but not up this way yet.

Hurst Fire: Evacuations ordered in Newhall Pass, southern SCV

By Signal Staff A new wind-swept brush fire erupted in Sylmar shortly before 10:30 p.m. Tuesday, quickly burning at least 500 acres, forcing freeway shutdowns and prompting evacuation orders affecting […]

signalscv.com

 

[dougbert]

time to weed wack all that brown california grass to nubs, I remember those days in my life down there

 

[GXMnow]

With my little incident yesterday, I am giving the battery system a bit of a workout. I posted in my Pergola Build thread, I mentioned my little slip up. Before 1 pm, the battery was full and the Victron charge controllers were going into float. So I decided to take manual control and set the XW to export to grid to use up the extra solar for some more SCE credit. Well, I got busy and forgot about it and ended up exporting around 3,000 watts to about 5:20 pm. Here is the trace from the XW. SCE has not posted yesterday yet.

This is actually a nice test to see how it would handle charging an EV.

I put the PLC back in control so it went back to just covering the house load with about 20 watts of export. It did make it all the way through the night and up until the sun came up this morning, but it pulled the battery down to where the JK BMS is reporting just 20% SoC. The voltage at virtually zero current is 50.4 or 3.6 per cell in my 14S setup. Going by the SoC voltage chart, that is about 25% so the BMS is pretty close. By 8:30 am the solar panels are making more than the house is using and the charge rate is starting to climb a little. The question is, will the system get all the way back to 100%? The XW has started charging and both Victrons are in bulk. At 8:30 the current into half the bank was just over 3 amps. The other half is typically a little more.

And I just noticed as I posted this pic, cells balanced within 1 mv, nice.