Feeding back to grid- challenges

[Alex Stewart]

Hi all, I have an 8kw Sunsynk inverter and started feeding back to the grid a week ago. Exciting times! However, the grid at times is being fed from my batteries which I don't want. Does anyone know how to adjust the inverter settings to prevent this? I would like the first priority of the pv generation to cover our load requirements, then charge batteries, then feed the grid but not from batteries even if they are fully charged. Any ideas?

[GreenFields]

You need to change your work mode settings. I only know the setting mode names in terms of the Deye-brand inverter, but right now you are in the "Selling First" mode.

You should best change over to the mode "Zero Export to CT," and then tick the "Solar Sell" box, and tick the "Load Priority" box. Or whatever the equivalent name is for the work mode settings in the Sunsynk-brand inverter. 

[Alex Stewart]

Thanks for your feedback. Hopefully Sunsynk as something similar. 

Edited September 11 by Alex Stewart

[GreenFields]

10 minutes ago, Alex Stewart said:

Thanks for your feedback. Hopefully Sunsynk as something similar. 

They do, it's the same inverter basically with the same hardware and functions, just a different interface.

[Alex Stewart]

11 minutes ago, GreenFields said:

They do, it's the same inverter basically with the same hardware and functions, just a different interface.

apologies for this perhaps stupid question: will the system with this setup still be feeding excess power to the grid ?

[Bobster.]

Not my business really, but is your system registered with your utility? Most places you will need a special meter to sell back, and the regular meter will either trip when the current starts going the wrong way, or will bill you as if you were drawing the same amount from the grid.

Certainly in Johannesburg if you are serviced by City Power you need to first register your system with them, then switch to the reseller's tariff which carries extra admin fees and which requires a special meter - at your expense. Which is why I don't sell back: I wouldn't even break even, I can only lose on the deal.

Edited September 11 by Bobster.
punctuation

[GreenFields]

6 hours ago, Alex Stewart said:

apologies for this perhaps stupid question: will the system with this setup still be feeding excess power to the grid ?

Yes, once your battery is full, it will send surplus solar power to the grid. But no battery power goes to grid.

If you choose the selling first priority, coupled with the Time-of-Use timer, you will be selling solar and battery power. As @Bobster. said, I assume your municipal approval to export to the grid is granted, but that's your business.

[akash3995]

Feeding power back to the grid presents several challenges, especially with renewable sources like solar or wind. The variability in energy generation due to weather conditions and the need for grid compatibility are major issues. Additionally, upgrading infrastructure, managing bidirectional energy flow, and ensuring grid stability during energy transfers are crucial hurdles. Addressing regulatory and financial barriers is equally important for successful integration. For more insights on energy management, feel free to check out FESCO.

[macafrican]

17 hours ago, akash3995 said:

Feeding power back to the grid presents several challenges, especially with renewable sources like solar or wind. The variability in energy generation due to weather conditions and the need for grid compatibility are major issues. Additionally, upgrading infrastructure, managing bidirectional energy flow, and ensuring grid stability during energy transfers are crucial hurdles. Addressing regulatory and financial barriers is equally important for successful integration. For more insights on energy management, feel free to check out FESCO.

It’s really not that big an issue and we have NRS that limit capacity export.     The variability in a minute of my solar is LESS than the variability in a minute of my loads.     The grid handles fine my loads ranging eg between 200 and 250kw in a minute, it handles exact same way, my solar export ranging between 200 and 250 kw.

As long as users stick to decent equipment and connect correctly, distributed generation actually IMPROVES the distribution grid because we help lift voltage in the street.    When they get smart, we will get to stage where I only export in peak time of use when they have a big need but then they need to pay me properly.   Then I’ll export from battery a constant kVA value.

There are far too many people spreading doubt, uncertainty, fear.     Usually those councils that don’t like losing revenue, or people selling solutions that need to pretend things are difficult.

[system32]

On 2024/09/28 at 10:15 AM, macafrican said:

It’s really not that big an issue and we have NRS that limit capacity export.     The variability in a minute of my solar is LESS than the variability in a minute of my loads.     The grid handles fine my loads ranging eg between 200 and 250kw in a minute, it handles exact same way, my solar export ranging between 200 and 250 kw.

As long as users stick to decent equipment and connect correctly, distributed generation actually IMPROVES the distribution grid because we help lift voltage in the street.    When they get smart, we will get to stage where I only export in peak time of use when they have a big need but then they need to pay me properly.   Then I’ll export from battery a constant kVA value.

There are far too many people spreading doubt, uncertainty, fear.     Usually those councils that don’t like losing revenue, or people selling solutions that need to pretend things are difficult.

It's very common for homes to sell excess to grid - read up on Australia and California and Europe.
Not so common in South Africa for homes to grid feed due to:

• registering process is is tedious (red tape) - needs streamlining
• registration process is costly due to consultants - needs streamlining
• bi-directional meter can be expensive - need cheaper meters
• limited to "net-zero" - can only receive money for what you consume - allow to sell all generated PV electricity
• rates paid to consumers are low making cost recovery difficult - better rates (eg CT has better rates)

Most of us just give up and only self-use.
This is a real pity as lots of excess home PV electricity power goes to waste.

Not sure why Metros don't encourage electricity from home users.
1kWh from the my PV system is the same as 1kWh from Eskom and mine is much cheaper.

If the grid-feed was encouraged, then new installs would be built and sized for that.
Instead they sized home PV for self consumption.

Electricity Minister Kgosientsho Ramokgopa needs to push Nersa, Eskom, Metros to fix the process for the benefit of the country.