Which hybrid/AIO/battery inverters allow programed export time under TOU plans?

[Hedges]

Those of us going under California's NEM 3.0 (Solar Billing Plan) will want to use battery to shave imports and exports much of the time, to avoid earning about $0.02/kWh credit for exports one minute and then paying $0.40/kWh for imports the next.

But the plan also pays large credits for a few hours per day, a few months out of the year. Large, like $3.00 to $4.00/kWh between 7:00 and 9:00 PM in September, if I read the table correctly.

NEM 3.0

diysolarforum.com

Which inverters with a battery allow us to program them to discharge battery and force feed grid during those times?

@Hightechlabs reports Midnight The One does.

Midnite Solar Announced their new 10kw AIO at Intersolar Today

Same generator for me. I had to roll it out last week. Nice thing is the wire's already run, I can likely remove the manual transfer switch/breakers. With a generator input, would this not need a chargeverter? It'd be solely to keep batteries topped in my case. Need to figure out how this...

diysolarforum.com

I can report that SMA Sunny Boy Storage does NOT. With older firmware I was able to set a negative value for watts in Performance Profile, and although the GUI lit up the field red to indicate an error (outside allowed 0 ... 500,000 range), it did accept the value and did export. However, I had to update to later firmware because it wasn't reliably charging every day. With latest firmware, it does NOT accept the negative number. I'm stuck with just the one -700W setting I used for test, can't set -5000W or more like I want to. And there is no going back, have not found a way (in software, plan to spoof analog CT reading if no other solution.)

Anybody else?

@Will Prowse you're the official reviewer of everything PV, and this will be an important topic for DIY and turnkey customers. They just may not know it until/if they ever figure out they've missed out. We've already seen forum members suffering from inappropriate peak-shaving times that failed to save money at true-up.

(This thread as requested in https://diysolarforum.com/threads/m...kw-aio-at-intersolar-today.76840/post-1136984 )

 

[DIYrich]

My Sol-Ark 15k can do it. My utility subsidized the cost of my batteries if I force discharge them between 3-8pm, Mon-Fri.

 

[SeaGal]

Solis (UK models) can force export under TOU - I believe the US versions can do that too as they seem to have similar user-interface - no doubt @Solar Guppy can confirm.

 

[ThaiTaffy]

Hopefully not breaking any rules here but the video below has an interesting concept using home assistant.
skip to 21:30 to hear him explain the software side of things if your not interested in the Tesla installation.

He's buying electricity at £0.15 a kWh and selling it back for £4

 

[zanydroid]

Which inverters with a battery allow us to program them to discharge battery and force feed grid during those times?

This is kind of a spectrum
- aware of and self-configures based on POCO hour-by-hour and month-by-month pricing rules
- modify by supported API
- modify by unsupported API
- modify by UI, so user changes it in August 1 and September 1 and changes it back on October 1
...

And theoretically this also varies based on PCS mode that the inverter is set to (and whether someone cares about respecting the PCS setting, if it's not locked).

The NEM3 opportunity was listed in an Enphase upcoming features slide deck someone sent me on Reddit few weeks back, so I expect them to implement some EZ mode version of this.

 

[HighTechLab]

I just realized I may have misunderstood the question. Are you referring to changing the schedule based upon certain months/season, or certain times of day only?

 

[Will Prowse]

Those of us going under California's NEM 3.0 (Solar Billing Plan) will want to use battery to shave imports and exports much of the time, to avoid earning about $0.02/kWh credit for exports one minute and then paying $0.40/kWh for imports the next.

But the plan also pays large credits for a few hours per day, a few months out of the year. Large, like $3.00 to $4.00/kWh between 7:00 and 9:00 PM in September, if I read the table correctly.

NEM 3.0

diysolarforum.com

Which inverters with a battery allow us to program them to discharge battery and force feed grid during those times?

@Hightechlabs reports Midnight The One does.

Midnite Solar Announced their new 10kw AIO at Intersolar Today

Same generator for me. I had to roll it out last week. Nice thing is the wire's already run, I can likely remove the manual transfer switch/breakers. With a generator input, would this not need a chargeverter? It'd be solely to keep batteries topped in my case. Need to figure out how this...

diysolarforum.com

I can report that SMA Sunny Boy Storage does NOT. With older firmware I was able to set a negative value for watts in Performance Profile, and although the GUI lit up the field red to indicate an error (outside allowed 0 ... 500,000 range), it did accept the value and did export. However, I had to update to later firmware because it wasn't reliably charging every day. With latest firmware, it does NOT accept the negative number. I'm stuck with just the one -700W setting I used for test, can't set -5000W or more like I want to. And there is no going back, have not found a way (in software, plan to spoof analog CT reading if no other solution.)

Anybody else?

@Will Prowse you're the official reviewer of everything PV, and this will be an important topic for DIY and turnkey customers. They just may not know it until/if they ever figure out they've missed out. We've already seen forum members suffering from inappropriate peak-shaving times that failed to save money at true-up.

(This thread as requested in https://diysolarforum.com/threads/m...kw-aio-at-intersolar-today.76840/post-1136984 )

Yes, agreed and the 18kpv and 12kpv have forced discharge/charge cycles. Very easy to setup. I have been using this feature for over a year:

During summer months in Vegas, 6-9pm costs a lot. So if my epcube is depleted, this will offset loads or charge up my EP cube in the afternoon if my air conditioners depleted them a good amount.

Also my epcube has this feature (but only offsets at a set time). Tesla powerwall does as well.

Here are the settings in the app. I do not use this feature in the EP cube. I use it to offset entire house and cycle down to zero and up to 100%:

 

[zanydroid]

I just realized I may have misunderstood the question. Are you referring to changing the schedule based upon certain months/season, or certain times of day only?

I think a starting point would be to collect the raw capabilities (from the manual and config UI, plus a separate prose description would be my preference) for a bunch of inverters in one place, and then they can be classified from there.

The original post gave one scenario where forced export is profitable (there are actually multiple in California), and then moved on to describing the limited capability on one specific inverter that prevents this from being done.

 

[Lt.Dan]

I too do this with my SolArk 15k. I dump about 50kWh from 4pm-9pm for this exact reason.

 

[Hedges]

I just realized I may have misunderstood the question. Are you referring to changing the schedule based upon certain months/season, or certain times of day only?

Both calendar date range and time of day.

If The One only does it by time of day, could change settings September 1st and change back October 1st.

Check the table shown in NEM 3.0 link I gave.
I think the tables differ for different people depending on when the go on NEM 3.0
This table shows 7:00 PM weekdays in September, credit of $3.84 toward "generation" and $0.06 toward "Distribution".
August, $0.98 for generation. October, $0.05 for generation.

The original post gave one scenario where forced export is profitable (there are actually multiple in California), and then moved on to describing the limited capability on one specific inverter that prevents this from being done.

Yes, one extreme example, several dollars per kWh.
Different customers/plans will have different profitable and unprofitable cases.
I think for NEM 3.0, we will want to program a fixed schedule. Some situations could require dynamic response to sources of market data (or maybe prices set one day in advance.

 

[zanydroid]

I think for NEM 3.0, we will want to program a fixed schedule. Some situations could require dynamic response to sources of market data (or maybe prices set one day in advance.

Yes, some of those UK posts on this subject suggest dynamic is needed. I think there’s some crazy Texan plans that can use it too (though in Texas Free Nights is much more lucrative for ESS, so that is an academic option no one cares about).

The NEM3 compensation table I believe is updated annually.

 

[zanydroid]

This table shows 7:00 PM weekdays in September, credit of $3.84 toward "generation" and $0.06 toward "Distribution".
August, $0.98 for generation. October, $0.05 for generation.

This is kind of hilarious gaming because distribution is like 50% of the total bundled rate. Or higher. So your payout is capped.

 

[Hedges]

Right.

There are 3 hours in August when we can get $0.22 to $0.32 credit toward distribution.
Trouble is that is only about 1:1 with what we pay, so can't bank enough to pay for usage other times.

What this may mean is our banked credits will pay for the "production" half of our winter heating bill, but we have to pay in cash for the "distribution" half of every kWh we use.

In other words, PV + battery will be good to zero our bill over the time period when battery capacity can shave peaks & valleys.
But it can only cover half the cost of our bill for seasonal storage.

The more programmable these inverters (or external management schemes), the better less bad off we will be.
I predict a .com business to reach in and optimize our situation, for a fee.

 

[zanydroid]

Are you sure the payout from this table can't be banked for the year?

I predict a .com business to reach in and optimize our situation, for a fee.

Enphase is working on exploiting this, and I suspect Tesla is too (assuming they didn't fire everyone that might need to work on it).

 

[Ampster]

Which inverters with a battery allow us to program them to discharge battery and force feed grid during those times?

I have had luck doing that with my SolArk but a recent glitch prevented me from doing that during a Grid Savvy event last night. I do no know the cause of the glitch or which settings may have been changed so I can't say if it is currently a feature that is repeatable. I will see today from 6 to 8PM when there is another event. @Lt.Dan also commented on that feature.

Outside of the above process and rate structures, Tesla and others have been pooling resources into Virtual Power Plants and getting market rates for brief periods.
EDIT: I just checked my Solar Assistant screen and it is back to exporting from my battery again. It is limited to only using 1kW of battery by the export limit of 8kW because I am already producing 7kW of solar. by the 6 to 8 PM Grid Savvy event my solar production will decline and it should use as much as 2.5kW of battery based on my settings.

 

[zanydroid]

SolArk now has marketing material about the NEM3 high value hours.

NEM 3.0

Sol-Ark® has NEM 3.0 ready solutions to help homeowners maximize savings and ensure future-proof energy independence and backup power.

www.sol-ark.com

 

[Hedges]

Their charts and text near them appear to say the battery is used to supply household loads in the evening, avoiding buying higher priced electricity from the grid.

However, "Between 6pm–8pm the battery will sell back power to the grid to maximize NEM 3.0 credits."
That appears to say credits are earned by backfeeding the grid from battery.

Which is what I'm looking for.
I've told SMA in a support thread I can't recommend SMA for NEM 3.0 customers if they don't allow forced backfeed to grid.

(I previously read the table as super peak starting at 7:00, ending at 9:00 PM. Slipped a row. It is starting at 6:00 PM ending at 8:00 PM.)

 

[zanydroid]

(I previously read the table as super peak starting at 7:00, ending at 9:00 PM. Slipped a row. It is starting at 6:00 PM ending at 8:00 PM.)

I think superpeak is a different thing with NEM3. Since your sell price is different than the buy price. $3 sell is way higher than the buy price at that hour (which is likely in $.5 to $.7 range depending on which plan you have)

 

[SeaGal]

I've told SMA in a support thread I can't recommend SMA for NEM 3.0 customers if they don't allow forced backfeed to grid.

Do your SMA inverters have support for Modbus-based power meters (e.g. Eastron/Chint/Acrel)? If so, then for us DIY'ers it's not rocket science to add a MITM Modbus device to dynamically import or export any amount of power to or from the grid under software control for inverters that don't have that inherent capability.

 

[Solar Guppy]

The Solis Hybrids (S6-EH1P11.4K-H-US ) support this , on the app ( or web portal ) the setting is under work mode -> Feed in Priority Mode. They have up to 3 programable time windows for separately charge and discharge and support the Sunspec for this feature as well so the utilities can control your unit on demand if that's what one would like.

 

[Rider]

Which inverters with a battery allow us to program them to discharge battery and force feed grid during those times?

The Solix X1 does, and their Solix F3800 does when used with their Smart Home panel. One of their selling points.

 

[Ampster]

I just checked my Solar Assistant screen and it is back to exporting from my battery again.

I was wrong about it working at the times I wanted but later did find the issue. I had to use the MySolArk app to fix it. It was one of the TOU times under System Work Mode parameters. You have to scroll down to the section where the Sell times are highlighted and make sure the TOU time period you want to export is highlighted. Also the amount of battery that will be used in kWhs is set in another section. It worked last night and I sold about 2kWs after covering house loads of 500 kWs (2500 kW setting).

 

[Hedges]

Do your SMA inverters have support for Modbus-based power meters (e.g. Eastron/Chint/Acrel)? If so, then for us DIY'ers it's not rocket science to add a MITM Modbus device to dynamically import or export any amount of power to or from the grid under software control for inverters that don't have that inherent capability.

Looks like they do:

"1 approved energy meter (WattNode® Modbus WNC-3Y-208-MB or WNC-3D-240-MB from
Continental Control Systems, LLC)"

WNC Series Meters for Modbus - Info - Continental Control Systems, LLC

WattNode® power meters for Modbus measure kW power and kWh energy in 120 to 600 Vac services with currents from 5 to 6,000 amp. Works on 1, 2, or 3 phase wye (phase to neutral) or delta (phase to phase) electrical services. Revenue grade ANSI C12.20 / ANSI C12.1 models available. Learn more...

ctlsys.com

Modbus RS-485

Modbus - Wikipedia

en.wikipedia.org

"
Modbus standards or buses include:[1]

• TCP/IP over Ethernet
• Asynchronous serial communication in a wide range of standards, technologies: EIA/TIA-232-E, EIA-422, EIA/TIA-485-A, fiber, radio frequency,...
• MODBUS PLUS, a high speed token passing network.

"

Although I are a Rocket Scientist, I'm also a Luddite and avoid programming hardware if I can accomplish same with a resistor or coil of wire.
I plan to spoof the CT (with burden resistor) by using step-down transformer & resistor to either drive a coil or to offset voltage. With a potentiometer, analog tunable.

That will require a timer to power it when offset required, so I'd likely still be using programmable digital electronics, but off the shelf. So your suggestion makes a lot of sense.

A uP (or other) man in the middle could also let me use as single energy meter to feed (original or adulterated) data to multiple inverters.

 

[SeaGal]

Although I are a Rocket Scientist, I'm also a Luddite and avoid programming hardware if I can accomplish same with a resistor or coil of wire.
I plan to spoof the CT (with burden resistor) by using step-down transformer & resistor to either drive a coil or to offset voltage. With a potentiometer, analog tunable.

Love that idea too. I miss my analogue electronic days

That will require a timer to power it when offset required, so I'd likely still be using programmable digital electronics, but off the shelf. So your suggestion makes a lot of sense.

A uP (or other) man in the middle could also let me use as single energy meter to feed (original or adulterated) data to multiple inverters.

Thanks, but I'll quickly add that the concept was not mine I've implemented a MITM Modbus system (using Python and RPi) based on the excellent code that @peufeu developed to do exactly what you are looking to do (i.e. force charge / discharge) from inverter programmatically -

see his Grugbus project detailed in this thread...

Solis S5: Various issues

Hello everyone! This is in France. The house has three phase power for the heat pump. I installed a Solis S5 hybrid inverter (S5-EH1P-6K-L) with two Pylontech US5000 and of course solar panels. It's a single phase inverter, I don't need three phase backup. My main reason for choosing this one...

diysolarforum.com

and code here...

GitHub - peufeu2/GrugBus: Convenient MODBUS abstraction on top of pymodbus to control Solis inverters

Convenient MODBUS abstraction on top of pymodbus to control Solis inverters - peufeu2/GrugBus

github.com

P.S. I'm also using it to feed two inverters from one meter.

 

[zanydroid]

The Solix X1 does, and their Solix F3800 does when used with their Smart Home panel. One of their selling points.

Which grids allow F3800 to sell? The solar build mag article from when those were announced only listed certifications for Solix X1 (1741SB 9540; I suspect it is CEC listed but F3800 is not)

The most recent article from that source says X1 has a NEM3 mode, wonder whether that is just self consumption or does the intelligent forced export.