Renewables: "talking 'bout my generation"

Oscargrouch

pinnks wrote: »

I am with E.On and typically have the money within a week as mentioned by Edwink.

Same here with E.On, normally within 4 working days... Good One E.One...

Nearly forgot...

....:rotfl: Don't you wish Jono...:D

edwink

1.23 O's today. Boring rubbish weather but no rain thankfully

Edwink

Martyn1981

jonokimber wrote: »

I guess time will tell unless anyone wants to chip in with a hypothesis?

Jono

Something in the back of my head/memory says a single MPPT is slightly more efficient, so long as there's no shading difference between the two strings, and so long as each individual MPPT can cope with the voltage and ampage.

I'm way out of my depth here, but if you had both strings running through a single MPPT, then that's 7 (2 parallel strings of 7 panels) x 31.88V = 223V, but the specs on that inverter say that each string can only handle 10A. But 3,990W / 223V = 18A. (Does that suggest maxing out at around 2,230W?)

Ironically, it looks like the inverter could handle all 14 panels on a single string/MPPT, or 2 strings on 2 MPPT's, but not 2 strings on a single MPPT.

Must stress here that I'm not an electrician, and my fumbling of the inverter specs is little better than a trained monkey trying to type Shakespeare ....... but does that sound like an issue to you, or anyone else?

If I've completely misunderstood this, please tell me, don't want to mislead anyone, and interested to learn more.

panel specs

inverter specs


[Edit:

jonokimber wrote: »

Having spoken to my installer I checked the voltage of my two strings and they were both identical and as expected.

Just a thought, and further confused myself, but if both strings were running through the same MPPT (and therefore string) how could you have had 2 sets of readings? Shouldn't it have shown up as one string, just half the voltage and twice the ampage (unless maxed out) of a 14 panel string? M.]


[Further edit: now having serious doubts that someone like me should comment on something as complicated as this. Thought of deleting, but will leave as an exercise in humility. M.]

Mart.

ajbell

2.62 Os yesterday. Pretty much all in the afternoon.

EricMears

Martyn1981 wrote: »

Just a thought, and further confused myself, but if both strings were running through the same MPPT (and therefore string) how could you have had 2 sets of readings? Shouldn't it have shown up as one string

All depends on how the two measurements were taken.

If the cables coming from panels were identified and two measuring points before the inverter were found then you could certainly write down two voltage results. However, if the two cables were joined inside the inverter's input box, they couldn't help but give the same voltage reading for each.

Martyn1981

EricMears wrote: »

All depends on how the two measurements were taken.

If the cables coming from panels were identified and two measuring points before the inverter were found then you could certainly write down two voltage results. However, if the two cables were joined inside the inverter's input box, they couldn't help but give the same voltage reading for each.

Thinking about it Eric I've made a big booboo. Jonokimber referred to two string readings, and the inverter specs say it can take 2 strings on each MPPT, so presumably it can report separate strings on each MPPT, giving up to 4 sets of data. I said:

Martyn1981 wrote: »

if both strings were running through the same MPPT (and therefore string)

but there is no 'therefore', it's still two strings. I knew I'd gone wrong somewhere.

What do you think about the Amp limit (per MPPT) would that act as a cap limiting the generation? Suggesting the problem has now been solved.

Mart.

rodee13

Quite pleased to achieve a new peak today of 3.6KW, thats 90% of max capacity. Helps to know all the panels are capable of performing well.
All the shadows will soon disappear at least till mid October. On target to achieve 2O's today.

ajbell

My 4kwp system was outputting between 3.58 and 3.72kw around mid day.
I was running around the house switching everything on.
I will NOT export.

rodee13

ajbell wrote: »

My 4kwp system was outputting between 3.58 and 3.72kw around mid day.
I was running around the house switching everything on.
I will NOT export.

maybe you should buy a storage heater to use the 2nd ouput of iBoost+. Makes so much sense on days like today.

Markj1110

3.06 O's today. best day since Oct 4th 2015. Sunny, but cold.