An Enphase Ensemble Installation

[svetz]

They have installed a separate meter for consumed and generated?

No, the netmeter reports the power I export to them and the power I import from them as two separate values. One meter, 3 readings (the 3rd is dnn, but don't know what that is, see What is the "dnn" reading?). See Using RF to read ITRON utility meters and

The 1000 kw consumed is for what period of time

That's not consumed, that's generated, and since the system went active on 1/27 (see post #11)

 

[svetz]

Made a first pass at some monitoring software that reads the two power readings from the Itron RF netmeter and the Enphase total watts produced. By looking at the delta I can tell how much power the house consumed. I'll post it up in another thread I've started on monitoring software some time this morning.

 

[svetz]

Got an unexpected alert from the software today! It's somewhere between an actual problem and a false alarm. As the sun drops in the west there is a small roof obstruction that casts a long shadow over one of the panels on the eastern array. Not like I'm going to remove the obstruction, so I'll probably just alter the time that particular test runs so I don't have long shadows tripping it. Still, cool to see it working as intended!

 

[svetz]

Got an email from my installer regarding the Encharge battery. Basically Enphase is complying with the CA public health order to remain-at-home for 3/17 to 4/7 (or later) to help curb the spread of COVID-19; so the launch is being postponed for an indefinite period. Sounds like a good move all in all.

 

[svetz]

Roof Prep

You probably noticed in the earlier photos that the roof is white. It's Henry's tropi-cool white silicone roof coating. The roof has been in the sun for a while in this photo and is obviously quite cool. I've been up there a lot, and it's always cool to the touch. The downside is it is very slippery when wet. In typical local style, it also took forever to get done, which helped push the deployment into 2020.

I wanted to put a new coating on before the panels went up as I didn't want to have to take them down in 10 years just to re-coat the roof (has a limited lifetime warranty so hopefully will last 30 years). I always thought it would be a good combination with bifacial panels, but those need to be elevated a bit off the roof and in my hurricane wind high velocity projectile zone that just wasn't in the cards.

I picked this coating from the CCRC data looking for a "cool roof". Henry 988 has the same CCRC stats as 887 (I think one is the homeowner version and the other a contractor):

​

AFAIK, this is the best there is for a DIYer to keep a roof cool, and that'll reduce the AC bill so you'd consume less power.
When I put it on my roof I even got a state rebate for an energy credit!

As you probably also noticed in the earlier photos, having a cool roof did not allow me to skip the elevated roof conduit nor the lower gauge because the NEC rules only use highest ambient temperature, not roof temperature. It's amusing that the elevated conduit temperature is hotter than the roof temperature.

 

[svetz]

Sam Vs. Reality
I've been using SAM to model my system as it takes into account local weather patterns and many other economic factors. It's a great tool for answering what-if questions. While SAM isn't that good for estimation of power on a day-to-day basis, I'm wondering how good it is over a month or a year on my east/west roof-flush mounted arrays. So let's find out....

	SAM	Actual	Accuracy
Jan	776.	Installed
Feb	890	918.75	5% (spooky, the soiling loss is set at 5%)
Mar	1209	1306	8%
Apr	1349	1315	8%
May	1404	1317	-6%
Jun	1270.75	1227	-3%
Jul	1299.1	1198	-8%
Aug	1247.21	1356	8%
Sept	1043.61	998	-5%
Oct	1005.44	875	-13%
Nov	769.033	724.7	-5%
Dec	734.15	773.1	6%
Total to date	12221.3	12008.6	-1.7%

 

[svetz]

Got a credit on my February bill! Probably won't see that again until Winter rolls around again, but it was nice to see!

In other news... the Encharge battery and smart switch are now showing on AltE. This note was interesting:

*NOTE: Installers must be certified to buy/sell the Enphase Ensemble system. Only certified systems will be warrantied.

 

[WildLeg]

I do believe that’s the best price around for the Encharge 10?? Thanks for input. Can’t remember...did you install all this yourself? We’re you your own general contractor? Did you put together your own permit packet?
Thanks

 

[svetz]

I do believe that’s the best price around for the Encharge 10?? Thanks for input. Can’t remember...did you install all this yourself? We’re you your own general contractor? Did you put together your own permit packet?
Thanks

I have a solar company doing it, but it's not delivered yet... Enphase shutdown for a while due to the health crisis and expected to start shipping them in mid April. So, no installation date for me yet.

 

[Picasso]

Wow 80lbs for the SmartSwitch nice big transformer.

 

[svetz]

Wow 80lbs for the SmartSwitch nice big transformer.

The way I understand it, the SmartSwitch is a glorified transfer switch, it's only job is to disconnect the house from the grid when it switches to battery.

 

[Picasso]

I thought all of these AC tied units cant form the 120 / N hence the need for a neutral forming transformer? and also to help with imbalance. SMA's unit is transformer and switch for the SMA storage.

 

[svetz]

I thought all of these AC tied units cant form the 120 / N hence the need for a neutral forming transformer? and also to help with imbalance.

Yes they are! Guess I shouldn't have left the details inside the "glorified" out. Here's what my setup looks like and a brief description of the parts in case I confused anyone.

​

• IQ7+ - these take the place of the MPPT/inverter in your typical string array. One for each panel so no worry about string shading (except this) and they output 240V AC. These are synchronous to the grid's signal and add to power, by raising their voltage the microinverters can export power to the grid. If the grid goes out, the microinverters shutdown, e.g., no power when the grid is down unless you've a SmartSwitch/Encharge or other AC coupling solution.​
• IQ Combiner - This allows multiple power wires from the roof to be combined into a single output. Has circuit breakers so could act as the AC disconnect in a traditional string system (I have a stand-alone AC disconnect switch too, not in the diagram). Also holds the Envoy. The Envoy is the "brains/communications" of the PV system and collects data from the microinverter / panels using the powerline protocol. It also uses Zigbee to communicate to Encharge And WiFi to the cloud.​
• Empower Switch - Technically this is a Microgrid Interconnection Device (MID). In a traditional AC Coupled String array this would be the transfer switch. But it does a whole lot more, including a neutral-forming transformer for split phase 120/240 V backup operation, and a future generator input connection. I suspect, but am not positive, that the Grid Forming "brains" are in here too, but it could be in the Encharge or Envoy.​
• Encharge Battery - In an AC coupled solution, this would be the LiFePO4 battery, a set of grid forming inverters (IQ8s, see speculation below), and communication package. The AC output is either grid synchronous (e.g., the TOU case) or the main signal source (e.g., the Grid down case), but the SmartSwitch might be the signal source too.​

Speculation
A normal grid forming inverter's job is to stabilize the voltage and frequency. The Encharge is probably neither a voltage source like an off grid inverter, nor a current source like a grid tied inverter. Instead, I suspect they are controlled grid forming sources. For example, in the TOU function, the IQ8 inverters in the Encharge must increase their voltage so power is consumed from the battery before the grid and the brains must manage/balance the voltage/load so as to not export power to the grid.

We can be pretty sure in an off-grid scenario the brains in the SmartSwitch ask the Envoy for the power available from the panels and it monitors the load to the house. If the panels have too much power, it adjusts the frequency and throttles the panel output back to meet the demand. If the frequency is at the max output, then the IQ8s in the Encharge probably act as voltage sources to supply current as needed to keep voltage stable.

 

[svetz]

Dzl thumbed up a post in the surge protection thread which reminded me to share that it turns out my house already had a whole surge protector on it. Never noticed it... until I had the net meter installed. Meant to mention it earlier, but the foot long sparks when the net meter was installed made me blank it out (forgetfulness, another undocumented danger of electricity ). My local power company installs them for $95. It sits behind the meter and pushes it out a bit. There are two LEDs that can be viewed through the visible circular window (one is really hard to see on mine) that indicate it's health. Not quite as nice as the Midnight.

 

[WildLeg]

Link to Enphase Ensemble Training Videos

Ensemble Training (EN-US)

Enphase Energy: Smart Solar & Clean Energy For Everyone

enphase.com

 

[svetz]

Watching the videos and found some interesting things:

• the encharge is designed to have water (rain) run through a part of it as the IQ8s are NEMA 6 (underwater) and it doesn't matter how wet they are. The other electronics (and presumably battery) are in a water tight NEMA 3r enclosure.
• You can daisy-chain them together, but restricted to a max of 8 gauge (max 40 amps).
• The envoy is the "brains" that tell the batteries if they should be charging or discharging.
• The IQ8s can operate in Grid-Tied (current source for TOU) or Grid-Forming (voltage source to supplement load) mode. Sounds like the Envoy switches it back and forth depending on the situation.
• Communication to the batteries is via the Envoy.
• A 10 kW Encharge is physically three 3.3 kW Encharge units. The downside of this is that the batteries in the 10 kW are not shared...each is discrete. So, if you want to add a DIY 10 kW battery to one of them you'll be limited to 1280W inverter it has. To get the 3840W from the inverter for that 10 kWh you'd have to augment all 3 sub units.
• Losing the internet connection can affect the warranty (sounds like you have to be offline for over a year).
• The Enpower reports grid and Encharge frequency to the Envoy, the Envoy has the brains to tell the batteries to adjust.
• The IQ8s in grid forming mode are responsible for stabilizing voltage and frequency to what Envoy specified.
• A cellular modem is required (although I don't believe this was quoted in my system...so old data?).
• IQ8s in Grid forming mode are fast (20 ns) in terms of supplying current/voltage, much faster than power curtailment which is 2-3s and controlled by the Envoy.
• They have smart breakers in their lab: Alexa: You only have 15 minutes power left, should I turn off your air conditioner?

 

[WildLeg]

Great recap Svetz. I haven’t made it through all the videos yet but so far i was disappointed to hear I’ll need the cell modem. The whole system seems like a sharp departure from the simplicity of past enphase products. However, i think they’ve put in the hard work and after it’s installed you won’t need to fiddle, massage or otherwise worry about the functionality...apart from manually shedding load in grid down situations to stretch capacity. Also, it hasn’t been clear to me until now, that both panels and batteries can contribute to total kW production simultaneously during an outage. Do i understand that correctly? Also, as far as communication PLC/Zigbee it was clear as mud...but i took it as everything can work independent of the other parts.

Thanks,
WL

 

[svetz]

......apart from manually shedding load in grid down situations to stretch capacity....

I'm working on that! See Features for the Perfect Monitoring Software for a Residential System, Smart Solar/Battery, and RF and the Smart Solar Home.

... it hasn’t been clear to me until now, that both panels and batteries can contribute to total kW production simultaneously during an outage. Do i understand that correctly?

Yes you do! Way slick eh?

... Also, as far as communication PLC/Zigbee it was clear as mud...but i took it as everything can work independent of the other parts.

As far as I know the envoy is powerline to the IQs and WiFi to the battery, the WAN, and the smart switch. I'm still not convinced the cellular modem is required. Why would it be if the Envoy can hold a year's worth of data waiting for the WiFi to come back up.

You can put a zigbee stick in the Envoy, looks like it's for their revenue grade meter. Not sure if it works with anything else.

 

[Picasso]

The warranty/internet connection seems odd to me. So is enphase telling me I can operate it in a way to harm it or will enphase adjust charge/discharge rates to conform as needed to keep warranty terms intact.

I still like this system the best, but I want 350vdc+ for my battery bank still keeps putting me back to SMA storage or when ever the one from ossiaco.com is released but the more I talk to them the more I think these guys dont want to support an offgrid users yet.

 

[svetz]

Tesla does the same thing (requires an internet link, although supposedly to update firmware to get the 10 yr warranty). It raised a stink in Florida a few years ago as long internet outages due to hurricane damage would have voided their warranties (I believe Tesla extended the times for affected locations). The Tesla Powerwall might be a less expensive way to go with Enphase.

 

[WildLeg]

Taking Ensemble sizing webinar as i type. Saw this interesting question and answer. It makes a strong argument for waiting for IQ8 on the roof.

"Q: Can you install more than 1.5x PV / Batery with the system automaticaly curtailing the PV amount above the 1.5x factor? If not, then with the PV IQ8 models will this change?

A: You should maintain the ratio for PV to Battery. Outside this range, there can be circumstances wher the microgrid can't absorb the full production and cause instability in the microgrid.
With rooftop IQ8, there will not be any ratio restriction."

 

[svetz]

As the Air conditioner kicks in more frequently the daily power consumption should start to outstrip the solar generation. Put together a little chart from the data I've been collecting from ( Features for the Perfect Monitoring Software for a Residential System ) and it looks like the trend lines crossed a few days ago. Unfortunately the data's not to precise as the "day" starts from when I turn the PC on which varies (for example, I've not yet had a day where solar production was over 50 kWh. In retrospect I should have measured at a time my PC was always on or run it on a PC that is always on.

​

Update: Realized I could just divide by the time to get the daily average to smooth out the time differences... graph updated. The power usage looks awfully high, not sure if that's just the heat wave + stay-at-home or if something is starting to break.

 

[svetz]

Last couple of days I've been getting, and ignoring, the soiled panel alert. I figured it was a case of the tolerances being too tight. I'm sure they are, but I went up to the roof to check and sure enough, the local trees had deposited a fine layer of pollen and the last couple of inches were particularly laden (probably from a very light rain we had). To hot to rinse them off now, but I'll do it tomorrow morning.

I had no idea that washing the panels would cause it to rain. Had I just waited a day I wouldn't have lugged the hose up to the roof, which tripped the latch mechanism on the ladder causing it to collapse (while on the roof), nor scared the bejusus out of my wife by tapping on the upstairs window with the hose end so I could get off the roof, nor have her spin around so fast that she caused her full coffee cup to go flying. Good thing the dog house gets wifi.

 

[svetz]

Heard from my Ensemble battery installer...sounds like the earliest I can expect it is June and that really depends on what CA does with reopening.

Looks like all that pollen on the panels was costing me about 10% energy. Guess I shouldn't have ignored the soiled panels warnings. Anyway, the system produced 52 kWh yesterday and there were some clouds around noon so hopefully will do better today. Nice to finally break 50 on a 7.8 kW system.

 

[waynelson]

Thanks for sharing your experience svetz, I'm getting an Ensemble IQ7 system (no batteries) on my house in the very near future and I'm excited to start making some electricity soon.