Renewables: "talking 'bout my generation"

legoman62

Only 3.25 O's yesterday
The low cloud and mist stayed with us til 16.00:(
Thought I was gonna hit single kWh figures for the day
Lot better today:D

[Deleted User]

22 kWh yesterday due to morning mist

The four days previous were all 24.xxkWh

Panels to hot??? But being SW and Scottish 26kWh in one day seems to be it's absolute limit...

Dave_Fowler

During this hot weather I've noticed how much lower than nominal the output from the panels are. From the 3kW system - where I've seen a sustained output of 3.2kW for some minutes during cold weather - now in the heat the output has been peaking at around 2.4kW - on a nice rounded curve.

I have finally got round to fitting a temperature sensor on the surface at the lower edge of one of the panels - just outside the silicon area. The temperature at 3:15pm today measures 50 deg C.

I'd expect from this that the output would be 25 x 0.4% lower than nominal. This should give an output of around 2.7kW (10% less than the nominal 3kW). The inverter is in a quite cool location so this should not be causing any problems due to overheating.

Any thoughts on where the extra 10% is going? Note: The temperature was at 3:15pm and the sensor is quite low down on the panel and along one edge, so the temperature in the middle may be higher but it would require an average temperature across the panel to be 75 C if the extra 10% were caused by panel heating only.

Dave F

John_Pierpoint

In this heat and dust, I wonder if the panels could need am overnight thunderstorm ?
My garden certainly needs a drink.

zeupater

Dave_Fowler wrote: »

During this hot weather I've noticed how much lower than nominal the output from the panels are. From the 3kW system - where I've seen a sustained output of 3.2kW for some minutes during cold weather - now in the heat the output has been peaking at around 2.4kW - on a nice rounded curve.

I have finally got round to fitting a temperature sensor on the surface at the lower edge of one of the panels - just outside the silicon area. The temperature at 3:15pm today measures 50 deg C.

I'd expect from this that the output would be 25 x 0.4% lower than nominal. This should give an output of around 2.7kW (10% less than the nominal 3kW). The inverter is in a quite cool location so this should not be causing any problems due to overheating.

Any thoughts on where the extra 10% is going? Note: The temperature was at 3:15pm and the sensor is quite low down on the panel and along one edge, so the temperature in the middle may be higher but it would require an average temperature across the panel to be 75 C if the extra 10% were caused by panel heating only.

Dave F

Hi Dave

Heat will certainly be a major factor, but the missing culprit is the clarity of the atmosphere.

The sky over the past few days has been a very light (Wedgewood) blue which has turned a much lighter (whitish) colour as evening sets in. This is reflecting a proportion of the available light back into space .... there's load of moisture in this warm air, it's only the high pressure which is preventing it from condensing and forming clouds ....

HTH
Z

Oscargrouch

7.04 O's today. Looking at the Spread Sheet; 1st 9 days of July 2012 = 28.28 O's, this July 9 days have done 47.64 O's...:beer:

EricMears

An even better day than yesterday in that generation curve was a proper 'normal distribution' model. Peak was alas only 3kW but not too disappointed with days total of 26.69 kWh

Alas, I couldn't find many things to do to use it all up :mad:

Aren't the nights beginning to draw in ! I'm sure I remember posting at this time a couple of weeks ago before generation had actually finished; stopped @21:15 tonight. Hey-ho, soon be Xmas

legoman62

6.61 O's or 26.44kWh yesterday:rotfl:
For today, Accuweather say lots of sun and local BBC say cloudy
BBC winning at the moment......unfortunately:(

Prothet_of_Doom

Having spent 6 months working as a Freelance Warranty Engineer, for a large conglomerate, with a customer who was another Congomerate, both big in wind turbines, I was shocked by how little of the broken electronics systems were actually repaired or refurbished and returned to the field. Numerous no fault found parts, were skipped, as the agreement was new unquestioned replacement. Shocked at the irony.

Sirlaughalot

Hi All,

I`m looking to possible install PV solar panels and have been speaking to Martyn1981 and others on another MSE thread. Been advised to amble over to this thread so here i am!

Just a general question if i may. Do the grid/energy company take all of the energy that you are unable to use yourself?

Thanks

SL