slychocobo
New Member
Hi, New to the whole Solar PV life, I tried searching but couldn't find anything that quite matched my question so I hope this is not a duplicate.
Recently had a Growatt SPH3000 inverter installed at my home the in roofspace along with 10x panels for about 4.2KwH generation, EPS for backup/UPS, 6KwH battery for storage and an 'Eddi' water tank heater for excess generation as our energy provider has a pretty lousy rate for feedback.
Generally the system works quite well, everything seems to be running as expected but we are seeing two odd behaviors we cant seem to pin down and honestly we don't know if its just oddities of how these AIO systems work or if something is wrong and could use an experienced hand to give advice.
1. We are often drawing power from the grid, even when there seems to be no good reason for it.
To give an example of what I mean. We had a situation where we were generating 1KwH from the panels, the battery has a solid charge of about 90%
The Inverter itself have a good charge in it and our house load according to the inverter will be around 400w, The Growatt will report (from the inverter display) that we are exporting -2/4w's, the rest is going to the battery.
But if I check the smart-meter itself, it will constantly show we are drawing 60w+ from the grid pretty consistently.
Even under low loads, around 300w with no solar, the inverter will say the house load is 300w, the battery is supplying 300w, but we will still be drawing 40-80w from the grid.
We've also noticed that the Inverter and the Eddi (Which both get their readings from CT clamps attached to the same cable (which is outside the consumer unit) will give quite different readings. While the Growatt will think there is no load at all (or that it's exporting slightly) the Eddi CT clamp will be reporting the 'correct' value that we are drawing 60w from the grid so we are working under the assumption that this mis-reading by the inverters CT clamp is the cause of the problem?
We arnt sure if the CT clamp might be at fault, or perhaps the make/cable difference is a factor (Both are wired up using Cat5e twisted pair cabling, but the CT for the Inverter has to travel up from the ground floor to the roofspace, while the Eddi is a few feet away) or if this is a wild goose chase we are on.
2. The other issue is also an odd one
We've noticed that on days of low solar production and the batteries run down they will reach about 10% then stop supplying the property with power and we'll go full back to the grid.
My understanding is that this is normal behavior to help maintain the life of the battery (although 10% seems high?). The problem however, is that battery will (quite slowly) over hours continue to discharge to about 8% battery life. The inverter then seems to switch over and will start charging the battery from the grid until the charge level reaches 12%. It then switches back to normal operation and discharges the battery to supply the property till it hits 10% again then stops.
This cycle then repeats till morning when the panels start generating power again.
We are unsure why this is happening, we are looking to switch to a variable rate tariff so do not want to risk the battery suddenly charging from the grid at 'peak' hours and costing us a small fortune.
But anyone with more experience with these systems or ideas, would be appreciated
Thank you
Recently had a Growatt SPH3000 inverter installed at my home the in roofspace along with 10x panels for about 4.2KwH generation, EPS for backup/UPS, 6KwH battery for storage and an 'Eddi' water tank heater for excess generation as our energy provider has a pretty lousy rate for feedback.
Generally the system works quite well, everything seems to be running as expected but we are seeing two odd behaviors we cant seem to pin down and honestly we don't know if its just oddities of how these AIO systems work or if something is wrong and could use an experienced hand to give advice.
1. We are often drawing power from the grid, even when there seems to be no good reason for it.
To give an example of what I mean. We had a situation where we were generating 1KwH from the panels, the battery has a solid charge of about 90%
The Inverter itself have a good charge in it and our house load according to the inverter will be around 400w, The Growatt will report (from the inverter display) that we are exporting -2/4w's, the rest is going to the battery.
But if I check the smart-meter itself, it will constantly show we are drawing 60w+ from the grid pretty consistently.
Even under low loads, around 300w with no solar, the inverter will say the house load is 300w, the battery is supplying 300w, but we will still be drawing 40-80w from the grid.
We've also noticed that the Inverter and the Eddi (Which both get their readings from CT clamps attached to the same cable (which is outside the consumer unit) will give quite different readings. While the Growatt will think there is no load at all (or that it's exporting slightly) the Eddi CT clamp will be reporting the 'correct' value that we are drawing 60w from the grid so we are working under the assumption that this mis-reading by the inverters CT clamp is the cause of the problem?
We arnt sure if the CT clamp might be at fault, or perhaps the make/cable difference is a factor (Both are wired up using Cat5e twisted pair cabling, but the CT for the Inverter has to travel up from the ground floor to the roofspace, while the Eddi is a few feet away) or if this is a wild goose chase we are on.
2. The other issue is also an odd one
We've noticed that on days of low solar production and the batteries run down they will reach about 10% then stop supplying the property with power and we'll go full back to the grid.
My understanding is that this is normal behavior to help maintain the life of the battery (although 10% seems high?). The problem however, is that battery will (quite slowly) over hours continue to discharge to about 8% battery life. The inverter then seems to switch over and will start charging the battery from the grid until the charge level reaches 12%. It then switches back to normal operation and discharges the battery to supply the property till it hits 10% again then stops.
This cycle then repeats till morning when the panels start generating power again.
We are unsure why this is happening, we are looking to switch to a variable rate tariff so do not want to risk the battery suddenly charging from the grid at 'peak' hours and costing us a small fortune.
But anyone with more experience with these systems or ideas, would be appreciated

Thank you