Slightly disappointed if I'm honest today......

[mattiker]

Hi,

Just out of interest - my 2.5KW system mostly south-south-west facing with micro-inverters - has only peaked at about 1.9KW but the actual output KWh looks largely in line with what most others are getting - I've printed off an estimate from PGVIS which has the average output per month/day through the year which I use as a benchmark (e.g. March should average 5KWh per day, 155KWh total). The installers estimated 2100KWh for the year but PGVIS estimated just under 2000KWh - I'll be happy with anything in-between.

The point I wanted to make was this.....when the scaffold was still up I was doing some roof work and noticed that my panels, Risen 250 SYP, had some condensation on them- it was a cold morning and the sun was still low. However my neighbours panels, SANYO hit250's had no condensation at all.....this suggest the sanyo panels have a lower thermal mass, which by my guess must be in part why they perform better in hot conditions.

 

[Jaycee]

Perhaps this is the birth (or maybe just the conception) of a hybrid PV/Solar themal system idea.... Why waste all that heat?

Saw just the thing at Ecobuild!

 

[finchy]

like the idea of that makes sense .....I'm adding thermal to our portfolio in the coming months !!

 

[langstroth2]

Interestingly, today a brief peak at 3,804W - the highest peak I've seen on our 4kw system (far higher than than during the recent blue skies, where we barely reached a peak of 3kw).

I put this down to:
- we actually had some wet stuff falling out the sky that had washed the panels clean
- they were cool, the sun having only just popped out from behind the clouds

 

[VMan]

Hi,

Just out of interest - my 2.5KW system mostly south-south-west facing with micro-inverters - has only peaked at about 1.9KW but the actual output KWh looks largely in line with what most others are getting - I've printed off an estimate from PGVIS which has the average output per month/day through the year which I use as a benchmark (e.g. March should average 5KWh per day, 155KWh total). The installers estimated 2100KWh for the year but PGVIS estimated just under 2000KWh - I'll be happy with anything in-between.

The point I wanted to make was this.....when the scaffold was still up I was doing some roof work and noticed that my panels, Risen 250 SYP, had some condensation on them- it was a cold morning and the sun was still low. However my neighbours panels, SANYO hit250's had no condensation at all.....this suggest the sanyo panels have a lower thermal mass, which by my guess must be in part why they perform better in hot conditions.

This is good to hear, my 2.4kwp system has only been peaking at 1.9kw too, i think this is quite ok at them moment, hopefully a cool summers day will increase this.

 

[FB.]

Interestingly, today a brief peak at 3,804W - the highest peak I've seen on our 4kw system (far higher than than during the recent blue skies, where we barely reached a peak of 3kw).

I put this down to:
- we actually had some wet stuff falling out the sky that had washed the panels clean
- they were cool, the sun having only just popped out from behind the clouds

It didn't rain here until late afternoon.
The morning had sunny spells, but, like you, I found the inverter was running at a higher output than any time previously.
My assumption was that with less sun, there was less evaporation of moisture from the saturated soil, so less haziness in the sky.
I've certainly felt that my panels could have been doing better in recent weeks, but were hampered by quite a lot of haziness.

 

[Solluva]

I also intend carrying out a few tests running water down the surface of my ground mounted array. I have a choice of water sources namely tap, a stream or if it ever rains again collected rainwater. I have my doubts as to whether tap water is a good idea over the longer term especially if your water is hard. If you live in a hard water area you have only to look at collective dried splashes of the water to see the build up of a film of calcium. This can be difficult to remove and would cut down on the panel’s performance. My tests will also compare the build up of deposits using these different water sources. I will eventually report back on this but please don’t hold your breath.

 

[Harry Worth]

As I understand it - The panel's output is specified at standard test conditions. One of these parameters is air mass which varies throughout the year. Air mass ranges from around 4 in the winter to around 1.5 or less in the summer. 1.5 is the test condition figure. You're only going to see this in the summer. It is possible to get less than 1.5 so you may see better than the power rating although this may be offset by the less than ideal ambient summer temps.

 

[stuart99]

Interesting thread, I've just been speaking to a guy in Australia who is experimenting with water cooling on his panels. Seems to have good performance improvement there, although the ambient temp is around 35oC !