So now I have a solar PV system how do I make the most of it???

derekoak wrote: »

I do not have solar panel but my son has 3.9Kw array. I expected that the panel would produce most electricity when there was maximal solar insolation. It appears not. May,June July and August are not as good as you might expect. I think this is because over 25 degree c solar panels are less efficient.
Perhaps in the future PV arrays will be water cooled and the warm water used for preheating domestic hot water. It struck me that it might be worth experimenting with misting the panel with cold water on hot days to see if the generation improves?
Does anyone know if this idea is true or has anyone done it?

Hello Derek, as D&D said, this is a little odd, highest generation should really be in May to August, with May through July very similar results, and August just starting to decline a little.

The panels do drop off as they get hot, they'll only max out for a minute or two, but then hold around 90% once hot. So long sunny days allow longer total generation, unless your son means peak generation for a short time, which might be during shorter / colder days.

You're spot on about cooling, for total generation you want long clear days, but for short peaks, a quick cloud or sun shower, then back to full sun (with cooler panel) can create some great figures. Once my 2.4 panels, through a 2.5 inverter, hit and held 2.6kW for about 2 mins following a short cloud. After about 2 mins sustained power back to about 2.2kW.

Heard of one guy spraying panels with a hosepipe on a very good day trying to get 30kWh's in one day (more for fun challenge), apparently burnt his bare feet!

Hope your son is having fun.

Mart.

rw268 wrote: »

Hi Guys, I've had a 3kw system installed and up on my roof for 2 months now - South facing at 40deg on the Isle of Wight. I have generated 24 kw in the first month and 36 kw in the second (Dec to Jan and Jan to Feb). I appreciate this will get better as the days get longer and we have more sun etc. But do these figures seem comparible to other users experiences?
Any information would be appreciated

Hello RW, as D&D said, that generation doesn't sound quite right, I put the info you posted into this site:

http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php#

and it suggested (only an average) 77 units for Dec, 94 for Jan, and 145 for Feb.

Obviously only estimates, and they will vary from year to year with varying weather. However, 24 and 36 seem a little low.

Can you post any more specs, such as panel types, inverter make and model. Is there anything odd about the installation, or simply a lot of shading at this time of year due to low sun angle (possible).

Mart.

lanstrom wrote: »

Hi Angela,

Welcome to the forums and don't forget to join the MSE Team on PVoutput ...[/url]

Look forward to seeing your outputs

Hope you don't mind but I've jumped in too :j

Martyn1981 wrote: »

Caz, sunny explorer is a bluetooth interface, what you need is a model name, possibly a Sunny Boy 4000?

Hopefully then we can check to see if it has MPPT.

Edit: apologies for the abbreviation, multi point power tracking, allowing two different feeds that don't effect each other.

Edit2: Not doing well today, sorry. To measure roof angle, two ways, take the dimensions of the triangle (post them if this is tricky) and use calculus to work out angle. Or watch as 'clever clogs' wife downloads a spirit level app to smart phone and measures the angle by holding it to the roof(s) total time about 1 min. Who do you reckon the smart one is?

Mart.

Thanks Mart. I know who isn't smart and that is me !!!!!!
Have just been up into the loft and the invertor is red and black and just says Sunny Boy on it but no sign of a model number. I am going to email our supplier and ask for the model number, is there any other info I should ask while I am in touch with them.
Once again thanks for your time