Powerwall reduces solar production when battery full

[Icepicknz]

Has anyone else noticed their solar production become very spikey and production drops off when the battery is full, this system is grid tied to it starts to export?

Here is an example of one of my properties where clear blue sky and sunny, battery is full, then when it starts exporting to the grid, the solar production drops and becomes spikey

{
site: {
last_communication_time: "2019-02-14T14:00:02.874335251+13:00",
instant_power: -5141.0185546875,
instant_reactive_power: -477.8748474121094,
instant_apparent_power: 5163.180817038107,
frequency: 49.95012283325195,
energy_exported: 3988273.026231209,
energy_imported: 5296034.060675653,
instant_average_voltage: 249.7544708251953,
instant_total_current: 0,
i_a_current: 0,
i_b_current: 0,
i_c_current: 0,
timeout: 1500000000
},
battery: {
last_communication_time: "2019-02-14T14:00:02.890246548+13:00",
instant_power: -10,
instant_reactive_power: 370,
instant_apparent_power: 370.1351104664349,
frequency: 49.966,
energy_exported: 2763080,
energy_imported: 3089920,
instant_average_voltage: 249.20000000000002,
instant_total_current: -0.30000000000000004,
i_a_current: 0,
i_b_current: 0,
i_c_current: 0,
timeout: 1500000000
},
load: {
last_communication_time: "2019-02-14T14:00:02.874218252+13:00",
instant_power: 248.8092015431506,
instant_reactive_power: -105.1058793002889,
instant_apparent_power: 270.09862020385634,
frequency: 49.95012283325195,
energy_exported: 0,
energy_imported: 10287107.550555553,
instant_average_voltage: 249.7544708251953,
instant_total_current: 0.9962152057621971,
i_a_current: 0,
i_b_current: 0,
i_c_current: 0,
timeout: 1500000000
},
solar: {
last_communication_time: "2019-02-14T14:00:02.874218252+13:00",
instant_power: 5423.555419921875,
instant_reactive_power: -30.802103996276855,
instant_apparent_power: 5423.642886711343,
frequency: 49.95012283325195,
energy_exported: 9317137.219724871,
energy_imported: 10950.70361376158,
instant_average_voltage: 248.38074493408203,
instant_total_current: 0,
i_a_current: 0,
i_b_current: 0,
i_c_current: 0,
timeout: 1500000000
},
busway: {
last_communication_time: "0001-01-01T00:00:00Z",
instant_power: 0,
instant_reactive_power: 0,
instant_apparent_power: 0,
frequency: 0,
energy_exported: 0,
energy_imported: 0,
instant_average_voltage: 0,
instant_total_current: 0,
i_a_current: 0,
i_b_current: 0,
i_c_current: 0
},
frequency: {
last_communication_time: "0001-01-01T00:00:00Z",
instant_power: 0,
instant_reactive_power: 0,
instant_apparent_power: 0,
frequency: 0,
energy_exported: 0,
energy_imported: 0,
instant_average_voltage: 0,
instant_total_current: 0,
i_a_current: 0,
i_b_current: 0,
i_c_current: 0
},
generator: {
last_communication_time: "0001-01-01T00:00:00Z",
instant_power: 0,
instant_reactive_power: 0,
instant_apparent_power: 0,
frequency: 0,
energy_exported: 0,
energy_imported: 0,
instant_average_voltage: 0,
instant_total_current: 0,
i_a_current: 0,
i_b_current: 0,
i_c_current: 0
}
}

 

[Icepicknz]

Here is an example from a different property, 120km away; 2 powerwall2, grid tied; and when i start to export to the grid, solar production drops off, but if i add load to the house such as charging my car, solar production increases. So for some reason the powerwall is telling the solar to backoff.

 

[PBBear]

instant_average_voltage: 249.7544708251953,

249.7V is quite high for grid -
my guess is that your system when exporting is driving the local grid voltage up until it hits 253V or so, hitting the upper threshold for excessive grid voltage in the inverter causing it to start throttling the panels. When you start the car charging, it causes the outbound current to reduce or switch to net import for the house, dropping the grid voltage, allowing the inverter to resume full production from the panels.

What sort of inverter do you have - and is it showing any overvoltage alarms? This is likely an inverter issue, you might need the high-voltage threshold in the inverter checked and reprogrammed.

Are you in a rural/regional area, or have very long power lines from your house to your local transformer, or otherwise have high resistance in your power lines? high power line resistance can cause the grid voltage at your house to rise and fall as the system is exporting or importing at a high rate.

 

[Icepicknz]

I have solar edge inverter and yes they do alarm and say over voltage and stop producing for 60 seconds at times for the rural site; the solax one does not.

The second site which is urban has 2 solar edge inverters, never get alarms and thats the second graph i posted. right now the battery is full and its doing what the graph showed...

Here is while car is charging

{
site: {
last_communication_time: "2019-02-14T14:58:25.590032888+13:00",
instant_power: -758.814453125,
instant_reactive_power: -1016.8030395507812,
instant_apparent_power: 1268.7347222769229,
frequency: 49.99971389770508,
energy_exported: 3099680.712888761,
energy_imported: 11012629.823722094,
instant_average_voltage: 237.17868041992188,
instant_total_current: 0,
i_a_current: 0,
i_b_current: 0,
i_c_current: 0,
timeout: 1500000000
},
battery: {
last_communication_time: "2019-02-14T14:58:25.590369219+13:00",
instant_power: 0,
instant_reactive_power: 660,
instant_apparent_power: 660,
frequency: 49.989000000000004,
energy_exported: 6260540,
energy_imported: 6970260,
instant_average_voltage: 237.25,
instant_total_current: -0.30000000000000004,
i_a_current: 0,
i_b_current: 0,
i_c_current: 0,
timeout: 1500000000
},
load: {
last_communication_time: "2019-02-14T14:58:25.590032888+13:00",
instant_power: 8081.363288944271,
instant_reactive_power: -828.4616845051482,
instant_apparent_power: 8123.717213849167,
frequency: 49.99971389770508,
energy_exported: 0,
energy_imported: 18735112.828611113,
instant_average_voltage: 237.17868041992188,
instant_total_current: 34.07289084599138,
i_a_current: 0,
i_b_current: 0,
i_c_current: 0,
timeout: 1500000000
},
solar: {
last_communication_time: "2019-02-14T14:58:25.590980548+13:00",
instant_power: 8859.740234375,
instant_reactive_power: -454.0113525390625,
instant_apparent_power: 8871.365358772997,
frequency: 49.99971389770508,
energy_exported: 11540058.290580893,
energy_imported: 8174.572803113857,
instant_average_voltage: 237.15379333496094,
instant_total_current: 0,
i_a_current: 0,
i_b_current: 0,
i_c_current: 0,
timeout: 1500000000
},
busway: {
last_communication_time: "0001-01-01T00:00:00Z",
instant_power: 0,
instant_reactive_power: 0,
instant_apparent_power: 0,
frequency: 0,
energy_exported: 0,
energy_imported: 0,
instant_average_voltage: 0,
instant_total_current: 0,
i_a_current: 0,
i_b_current: 0,
i_c_current: 0
},
frequency: {
last_communication_time: "0001-01-01T00:00:00Z",
instant_power: 0,
instant_reactive_power: 0,
instant_apparent_power: 0,
frequency: 0,
energy_exported: 0,
energy_imported: 0,
instant_average_voltage: 0,
instant_total_current: 0,
i_a_current: 0,
i_b_current: 0,
i_c_current: 0
},
generator: {
last_communication_time: "0001-01-01T00:00:00Z",
instant_power: 0,
instant_reactive_power: 0,
instant_apparent_power: 0,
frequency: 0,
energy_exported: 0,
energy_imported: 0,
instant_average_voltage: 0,
instant_total_current: 0,
i_a_current: 0,
i_b_current: 0,
i_c_current: 0
}
}

When i stop car charging

{
site: {
last_communication_time: "2019-02-14T15:00:47.490337894+13:00",
instant_power: -7608.82568359375,
instant_reactive_power: -460.5142517089844,
instant_apparent_power: 7622.7489568621495,
frequency: 49.95012283325195,
energy_exported: 3099921.4073332055,
energy_imported: 11012629.823722094,
instant_average_voltage: 240.96484375,
instant_total_current: 0,
i_a_current: 0,
i_b_current: 0,
i_c_current: 0,
timeout: 1500000000
},
battery: {
last_communication_time: "2019-02-14T15:00:47.490959556+13:00",
instant_power: 10,
instant_reactive_power: 650,
instant_apparent_power: 650.0769185258004,
frequency: 49.947,
energy_exported: 6260540,
energy_imported: 6970260,
instant_average_voltage: 241.3,
instant_total_current: -0.30000000000000004,
i_a_current: 0,
i_b_current: 0,
i_c_current: 0,
timeout: 1500000000
},
load: {
last_communication_time: "2019-02-14T15:00:47.490337894+13:00",
instant_power: 711.2451255442814,
instant_reactive_power: -412.9186876449841,
instant_apparent_power: 822.4180635278852,
frequency: 49.95012283325195,
energy_exported: 0,
energy_imported: 18735203.972222224,
instant_average_voltage: 240.96484375,
instant_total_current: 2.951655164610632,
i_a_current: 0,
i_b_current: 0,
i_c_current: 0,
timeout: 1500000000
},
solar: {
last_communication_time: "2019-02-14T15:00:47.490467893+13:00",
instant_power: 8315.5302734375,
instant_reactive_power: -614.8233642578125,
instant_apparent_power: 8338.22831887523,
frequency: 49.95012283325195,
energy_exported: 11540390.128636448,
energy_imported: 8174.572803113857,
instant_average_voltage: 240.95181274414062,
instant_total_current: 0,
i_a_current: 0,
i_b_current: 0,
i_c_current: 0,
timeout: 1500000000
},
busway: {
last_communication_time: "0001-01-01T00:00:00Z",
instant_power: 0,
instant_reactive_power: 0,
instant_apparent_power: 0,
frequency: 0,
energy_exported: 0,
energy_imported: 0,
instant_average_voltage: 0,
instant_total_current: 0,
i_a_current: 0,
i_b_current: 0,
i_c_current: 0
},
frequency: {
last_communication_time: "0001-01-01T00:00:00Z",
instant_power: 0,
instant_reactive_power: 0,
instant_apparent_power: 0,
frequency: 0,
energy_exported: 0,
energy_imported: 0,
instant_average_voltage: 0,
instant_total_current: 0,
i_a_current: 0,
i_b_current: 0,
i_c_current: 0
},
generator: {
last_communication_time: "0001-01-01T00:00:00Z",
instant_power: 0,
instant_reactive_power: 0,
instant_apparent_power: 0,
frequency: 0,
energy_exported: 0,
energy_imported: 0,
instant_average_voltage: 0,
instant_total_current: 0,
i_a_current: 0,
i_b_current: 0,
i_c_current: 0
}
}

So yes there is about a 5v change, probably within tolerance in urban hence why i only drop about 0.5 - 1.2kw of solar production, at the rural location i lose about 3kw

 

[Icepicknz]

You can see on the extended graph for both properties the voltage increase

Rural holiday home - Tia St Atiamuri NZ 10.900kW | Live Output
Urban Home - Dayna Ave Tauranga NZ 11.600kW | Live Output

So i guess the next question is, is there anything I can do? Do i need to increase the tolerance of the solar edge or something?

 

[PBBear]

You can see on the extended graph for both properties the voltage increase

Rural holiday home - Tia St Atiamuri NZ 10.900kW | Live Output
Urban Home - Dayna Ave Tauranga NZ 11.600kW | Live Output

So i guess the next question is, is there anything I can do? Do i need to increase the tolerance of the solar edge or something?

Yes - I'd be checking with the installer of your SolarEdge to see if it's high voltage alarm limit can be configured higher.
Here is an article talking about the same issue, but in Western Australia and referencing Fronius inverters.

In New Zealand, I dredged this up: http://www.powerco.co.nz/uploaded_f...p-to-10kw-connection-standard---generate.docx.
Section 2.3 suggests a inverter in NZ should start throttling when the grid voltage exceeds 243.8V, which is surprisingly lower than Australian levels, and if your inverters are set to throttle at that level, would explain your experiences.

This link http://www.solaredge.com/files/pdfs/viewing_grid_protection_values.pdf. describes how to change the config of a SolarEdge inverter - theres a NZ number for Solaredge Support on the last page.

Also, bug your power company to get the grid voltage reduced at both locations, and show them your graphs to prove it - when you're NOT exporting, the PowerCo document suggests the grid voltage should be 230VAC. If your inverters are already set to the highest voltage permitted in NZ, and you are only permitted a 6% rise above this, then this might be your only solution.

Oh - and relevent to this thread, be happy its not actually your Powerwall thats reducing your solar production, its your inverters

If all that doesn't work - consider rigging some sort of system that automatically charges your car, or heats a swimming pool, or something when the solar production exceeds a certain level (might be a setting in the inverter, Fronius inverters can do this) - you might as well be using the power for good rather than losing it when exporting.

(also read Section 4 of https://www.ea.govt.nz/dmsdocument/...echnologies-affecting-security-or-reliability. - a 2016 short consultant study highlighting these things in NZ - they know about it, even if they can't figure out how to solve it)