Hi All

I am running a Sunsynk 5,5kw with Revov 10,2 KWH battery setup.  We have all seen the efficiency claims of inverter's however has anyone actually tested this?

For interest I have pasted extract of the Sunsynk spec sheet on efficiency.

• Max. Efficiency 97.60%
• MPPT Efficiency 96.50%
• Euro Efficiency 99.90%

I have recently installed the new Sunsynk logger and decided to analyse the results.  I have 2 months data so far.  (I have two years of data stored on the solarman cloud which I have not yet analysed)

Jan 2022

Theoretical load = Import + Discharge + (PV - (export+charge)) 
52,7 + 29,9 + (52,4 - (0,1 + 28,1)) = 106,8

Measured load = 103,7

Efficiency 103,7/106,8= 97,09%. (Pretty good and in spec)

 

Subsequently my inverter went in for repairs and they changed all the control boards to the latest versions and the results are as follows?  The results below are from my semi new machine.

Feb 2022

Theoretical load = Import + Discharge + (PV - (export+charge)) 
77,6 +46,7 + 114,1 - (2 + 51,2)) = 185,2

Measured load = 169
Efficiency 169/185 = 91,25% (Quite a bit lower than spec?????)

 

 

1. Anyone else willing to share their graphs to check efficiency? 
2. Curious how the new machine seems to be less efficient?
3. Any suggestions on a better way to calculate the overall efficiency?
    

Looking forward to hearing from all the Sunsynk/Deye inverter fans

Regards

 

 

This should give a good idea of how the efficiency tracks over time.  Notice the result after repair.  Will monitor for a while and if it stays much lower like this will definitely get in touch with Sunsynk to find out why.

@ErwinK tried measure the efficiency of a SunSynk before and ended up claiming between 80% to 17.5% loses in this thread:

 

Thank you PowerUser, helpful information.

For those that are interested I took this issue further to analyse the efficiency at a daily level, before and after rebuild.

This image will help you better understand how the inverter works and also what I plotted on the graph using the data from the inverter's logger (before and after the rebuild).

 

Label 1 = PV power

Label 2 = battery power (positive discharge, negative charge)

Label 3 = Inverted AC power from DC to be used for loads and export.

Label 4 = power used by backup circuit (load output)

Label 5 = power used by non-essential circuit(geysers, pool, stove etc)

Label 6 = power measured at inverter's CT coil, placed at main feed from utility.  It measures any power ”purchased and controls backed if no export power allowed by utility.

 

I agree that my logged ratio of 3/(1+2) may be a little crude but it does show a trend. Blue line - sunny day before rebuild, orange line, sunny day after rebuild.  I did a couple of these comparisons on different days with varying solar irradiance. The trend was the same, flat line before rebuild and a parabolic line after rebuild.  Average of daily total of 3/(1+2) before = +- 95%, average daily total after of 3/(1+2) after = +- 85%.

 

According to me a trend like this indicates something is not right?  Any ideas what this may be?