Enecsys Monitor - continues to under-report generation

[tc847]

On another thread I reported that in December the Enecsys Monitor was reporting *lower* generation than the official generation meter.  Expectation would normally be that (mostly due to cabling loss) the Monitor would be higher.
Same thing has happened in January.

Dec: Enecsys total 31.3kWh; Generation Monitor 34kWh
Jan: Enecsys total 57.7kWh; Generation Monitor 62kWh

I have either 2.3kW or 2.25kW or 1.9kW power array (depending on which bit of inaccurate paperwork I read from the installers - who did an OK job but clearly are illiterate or innumerate or simply incompetent at documentation).  Most likely it is 2.25kW unless they actually switched the panels between me looking at them on Friday and them actually getting on the roof on the Monday.

None of the variations in power would explain the 7-8% variation I am seeing (2.3 to 2.25 is too small a gap and 1.9 to 2.25 is too big).

So for now I shall simply be thankful that I am obliged to submit readings from the Generation Meter to SSE.

[Wickham]

Has your internet been down for an extended period? I've found that the micro-inverters store data and dump it in the first hour after the internet is live again, but I'd like to know how long they can store data, perhaps not during a two-week holiday which would result in the Enecsys data losing some data.

Have you still got a logical reading for most daylight hours on every day or are some hours/days missing?

At the top of the Enecsys screen you will see the kWp of your array recorded. Which value is there? I don't think a wrong value will make any difference as kWh is kWh regardless of how large or small your array is recorded.

[tc847]

Dear Mr. Wickham,

Taking each of your questions in turn.

- Not for any significant period.

- Yes; to the best of my ability to validate.

- 2.25k (because presumably that is what they were told by the installer, not because it knows); I don't know how it calculates energy generated or current power but it is clearly possibly that if they have got incorrect information on the panels that whatever calculation it uses goes awry.

I am just happy to see the kWh piling up on the Generation Meter in the expectation that one day SSE will pay me some money....subject to contract, see website for full T&C.

TC

[Nick57]

Hi,

I have same issue with the monitoring system, and we have a 50MB Internet connection and no problems with losing connection!
For sure there is something with their software, they say it is still in Beta version, what I think is that they use 230 volt to calculate the power generated and not the voltage of the grid. We have had so many problems with our installation that we found our voltage way to low [196] and it was improved by our supplier we read now between the 238..242 volt.  Also don't forget you can have just a new tick at the end of the day, but in reality you need the next day to generate the rest [900w] to get a new tick on your feed-in meter. But the monitoring system does need to have more improvements, I would like to see an export function in it as well ;-)

Nick

[Nick57]

Right, today is nothing but snow and overcast, but funny enough we are producing some energy [1KwH since 8 this morning] whilst the Enecsys monitoring system shows all panels are 0. I know the panels always showed 6watt to begin with, so I think and start to believe this is maybe the reason of the difference showing on fit meter and monitoring system.

Any one else with Enecsys noticed this? or are we the only one out there???

Nick

[Wickham]

My Enecsys website shows all my inverters showing 0 in the early morning then 10 before they get going. In the evening they go down to 9 before cutting off.

Overall my Enecsys total is 4% more than the generation meter due to losses in the inverters and cable I suppose.

I only use the website to make sure that all the inverters are working, all about the same W or I find out why not, like a shadow or leaf on the panels. I don't pay much attention to the overall Enecsys total as it's bound to be different from the generation meter.

[tc847]

Update for Feb:
Enecsys 79.5kWh Generation Meter: 85kWh

No internet downtime during the month.

Clearly the monitor software is incorrectly calibrated somewhere along the line.

TC

[series530]

Call me sad (many do, I am sure)....

I keep a spreadsheet that maps the PV meter against the Enecsys site and my independent EnviR/Optismart. It's still fairly early days (a month or slightly more) but

Enecsys is notoriously inaccurate when the harvest level is low ... The Enecsys data seems to report the incoming energy from the panel and not the energy transferred to the PV meter. Enecsys also claim that the system is not calibrated for anything more than consumer usage. It must be remembered that the micro inverters consume power and this power is taken from the panels and not from the grid. The moment the inverters come out of sleep they consume energy. On very sunny days the power that they consume is negligible compared to the solar harvest (just a couple of percent). On a dull day, they will consume 50 or more percent of the harvest. I'm not at home and don't have access to my data. At the moment, my system is running at about five percent above the actual harvest. I suspect that as the irradiance increases the efficiency will increase and I will get nearer to 3.5% or so. FWIW, the EnviR is about two percent off.

An Internet outage will result in data being queued and then a spike in the harvest when the system comes back. This is very irritating because is skews the statistics on the report. This happened last week. The EnviR, in an outage, just doesn't report anything so is inferior in this regard.

System losses through cabling will have some effect. A decently installed system will show minimal losses in this regard. The killer is system inefficiency skew when the harvest is low. Your yield indicates a low average yield during the months described and actually seems like the system is behaving normally to me.

[Wickham]

Your yield indicates a low average yield during the months described and actually seems like the system is behaving normally to me.

tc847's reduction from 85 to 79.5 for a winter month when generation will be lower than in summer also seems OK to me, it's a 6.5% reduction and should be less in summer months. My reduction was 9.36% in December, but over nine months averages just under 4%.