Hello All

So I had solar panels installed about 5 years back. At the time Solar was quite new to me and I went on the advice of the installer as to the placement of the panels

What I knew was the following

• In South Africa North facing panels would be the best
• If you could not have North then North West would be next best ( not entirely sure why )

I have recently upgraded my Inverter to a Hybrid 8kw Deye Inverter and very interested in analyzing my houses solar production during the day with the intention of seeing if I can perhaps optimize my current solar panel placement for better solar production without having to buy additional panels at this stage

• I currently have 20 X 300w Panels ( potential of 6kw, this was inline with my original 5kw inverter)
• I don't have any North facing roof fronts so I have a combination of 10 panels on one NW facing roof and 10 panels ( split 6 / 4 ) on two NE facing roofs

What i have seen

• Maximum production at any point is about 4.5kw
• Round about 12 noon every day there is a substantial drop off, it recovers a little but never to pre noon levels
  • What I am thinking is at noon my NE facing panels are probably not getting as much sun as they were pre-noon
  • Also my other 10 NW facing panels have to compete with some tall trees and I know are not as effective as I would like especially after 3PM when the sun goes behind the trees
• I have also noticed that my production seems to mimic my consumption from noon onwards ( see graph below ). I recall reading somewhere that the panels will reduce production based on the load required. If so where can I configure it to not do that?

 

• Is there a way on the Deye inverter to see what each PV (PV1 an PV2 produces each day). I have looked but all I can see is either sum production or current production of the P1/P2 at that point but I would like to see that split over a 24 hour period to assess which panels collection is producing the best
• I am considering moving all my NW Panels to my SE roof thus maximizing production from 6AM to 12 Noon knowing that the current 10 on my NW roof are literally ineffective from about 3PM in the afternoon ( if not early based on the drop of seen in the graph below)

Thanks

 

4.5 kw peak seems about right, esp with that string orientation. The heat (if you are in GP) will also cause some efficiency loss. The PV throttling down to meet demand is a feature not a bug - the only way you can change this is to have more load at those times OR export that excess PV either to the grid or to non-essential items. I am guessing that your batteries are topped up and 100% by 12pm?

On solarman you cant view the DC split on the main screen / graph. Navigate to Device > Inverter>Statistics. Select your time frame then click the graph and select Parameter Selection. Select DC Power for MPPT 1 and 2 and it should give you the required view. This is on mobile app and Solarman Home. On the web once you get to Device then scroll all the way down and you';ll find the same graph that you can then change

Hi

I would need to confirm but yes I think you are right that by 12 the batteries are fully charged therefore there is no where else for the excess energy being produced to go. Cant really afford to add a 3rd battery at this stage.

 My geyser is currently set to heat from 7am to 3pm and am guessing is also at max temp by 12 noon. Looking at my graph for production and consumption I could maybe set the geyser to only heat from 9am onwards. Just need to get the entire family then to either shower at night or morning not both because at night it has no time to recover for the morning session. My pool pump is already running 7am to 3pm as well so in terms of load there is not much more I can have running at 12.

3 minutes ago, MarkZA79 said:

Hi

I would need to confirm but yes I think you are right that by 12 the batteries are fully charged therefore there is no where else for the excess energy being produced to go. Cant really afford to add a 3rd battery at this stage.

 My geyser is currently set to heat from 7am to 3pm and am guessing is also at max temp by 12 noon. Looking at my graph for production and consumption I could maybe set the geyser to only heat from 9am onwards. Just need to get the entire family then to either shower at night or morning not both because at night it has no time to recover for the morning session. My pool pump is already running 7am to 3pm as well so in terms of load there is not much more I can have running at 12.

Or have your geyser run from 7-9 then again after 11 / 12? Try spread the load a bit? Washing machines? Dishwashers? Aircons? Start baking / cryptomining?

30 minutes ago, mzezman said:

4.5 kw peak seems about right, esp with that string orientation. The heat (if you are in GP) will also cause some efficiency loss. The PV throttling down to meet demand is a feature not a bug - the only way you can change this is to have more load at those times OR export that excess PV either to the grid or to non-essential items. I am guessing that your batteries are topped up and 100% by 12pm?

On solarman you cant view the DC split on the main screen / graph. Navigate to Device > Inverter>Statistics. Select your time frame then click the graph and select Parameter Selection. Select DC Power for MPPT 1 and 2 and it should give you the required view. This is on mobile app and Solarman Home. On the web once you get to Device then scroll all the way down and you';ll find the same graph that you can then change

Thank you for the Solarman Info, exactly what I was looking for

So based on what I am seeing is the drop at noon is like said likely due to reduction in load so reduction in power and not so much position of sun in relation to the different string sets as they appear to be pretty much working in sync

3 minutes ago, MarkZA79 said:

Thank you for the Solarman Info, exactly what I was looking for

So based on what I am seeing is the drop at noon is like said likely due to reduction in load so reduction in power and not so much position of sun in relation to the different string sets as they appear to be pretty much working in sync

 

To further prove this - try push your load to later in the day on a fully sunny day and see how that stacks up

I have not divided by house into essential and non essential, everything runs off the inverter apart from my tenant who opted not to share the Solar benefit

If one was hypothetically able to sell power back to Eskom what power settings would one use on the Inverter

• You would have to tick "Solar Sell"
• Max Sell Power - I guess this is max Watts you would want to sell (every 24 hour)
• Zero Export Power - I have read that 20-100 does not supply the grid. What would be the maximum value to use here? Does 0 mean no limit or nothing at all?

On 2023/01/16 at 2:24 PM, mzezman said:

To further prove this - try push your load to later in the day on a fully sunny day and see how that stacks up

So I tried as suggested to shift my load around, still need to tweak it but already see a bit of an improvement

The noon dip is not as drastic and not for as long

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

56 minutes ago, MarkZA79 said:

I have not divided by house into essential and non essential, everything runs off the inverter apart from my tenant who opted not to share the Solar benefit

If one was hypothetically able to sell power back to Eskom what power settings would one use on the Inverter

• You would have to tick "Solar Sell"
• Max Sell Power - I guess this is max Watts you would want to sell (every 24 hour)
• Zero Export Power - I have read that 20-100 does not supply the grid. What would be the maximum value to use here? Does 0 mean no limit or nothing at all?

 

To sell to Eskom, you could either choose "Selling First" or if you choose "Zero Export to Load" or "Zero Export to CT", then you must have the "Solar Sell" box next to it ticked. The behaviour under each option will be a bit different with regard to prioritizing of charging the battery and supplying the loads first, versus selling as a first priority.

 

For "Zero Export Power" the aim is usually not to maximize the value, but to keep it as low as possible while still keeping your municipal meter happy because some prepaid meters can trip if it senses any reversal of power into the grid (or bill you for your exports). The "Zero Export" control with the CT-coil is not 100% steady, there could be rapid power changes with the weather or loads that the inverter must adjust to, so if you keep the value at "000" there's a bigger chance you could momentarily export enough power past the CT coil to trip the meter before the inverter has chance to scales back production to get back to a net zero level.

Keeping a steady Zero Export Power setting "020" (20W minimum steady import from grid) is often okay because it gives the inverter better chances to avoid exporting power past the CT coil. Best is to experiment and see what's the lowest value that works for your meter setup.

I do net metering and export to the grid, so I don't care that mine is set at "000."

23 minutes ago, GreenFields said:

To sell to Eskom, you could either choose "Selling First" or if you choose "Zero Export to Load" or "Zero Export to CT", then you must have the "Solar Sell" box next to it ticked. The behaviour under each option will be a bit different with regard to prioritizing of charging the battery and supplying the loads first, versus selling as a first priority.

 

For "Zero Export Power" the aim is usually not to maximize the value, but to keep it as low as possible while still keeping your municipal meter happy because some prepaid meters can trip if it senses any reversal of power into the grid (or bill you for your exports). The "Zero Export" control with the CT-coil is not 100% steady, there could be rapid power changes with the weather or loads that the inverter must adjust to, so if you keep the value at "000" there's a bigger chance you could momentarily export enough power past the CT coil to trip the meter before the inverter has chance to scales back production to get back to a net zero level.

Keeping a steady Zero Export Power setting "020" (20W minimum steady import from grid) is often okay because it gives the inverter better chances to avoid exporting power past the CT coil. Best is to experiment and see what's the lowest value that works for your meter setup.

I do net metering and export to the grid, so I don't care that mine is set at "000."

Just to add the image is not mine, I took it off the net just to show the options

Does the 000 mean no limit?

I am still confused

I am have been experimenting with the "Zero Export to CT" and "Solar Sell" options

Even with these ticked once my batteries are fully charged the PV production still throttles back to match the required load

It does not produce as much as it can and then sell this back to the grid

It seems the only way to keep the panels producing as much as they can is to get the houses load to stay high

Am I correct in this understanding?