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

spaine

Hi edwink,

I've been waiting over 4 months for EON to send me a contract. I've now written to complain after being told its in the post .. another dept needs contacting to send a duplicate, having escalated to mangers and being told I'll get it by email .. still no luck :mad:

John_Pierpoint

If I have a set of panels on my roof and so does my neighbour; how, at noon on a sunny day, does my inverter recognise a power cut and then turn itself off.
Would not it assume that my neighbours panels were creating the mains supply and likewise their inverter would recognise that power was being supplied from my inverter and assume that was the mains power supply?

Even the next morning could one in theory get the whole estate started up by plugging in a small "Honda" generator, to create a cascade of awakening PV installations.:huh:.

GaryMo_2

John_Pierpoint wrote: »

If I have a set of panels on my roof and so does my neighbour; how, at noon on a sunny day, does my inverter recognise a power cut and then turn itself off.
Would not it assume that my neighbours panels were creating the mains supply and likewise their inverter would recognise that power was being supplied from my inverter and assume that was the mains power supply?.

If your house is subjected to a power cut then the inverter will detect the loss of the AC supply and shut itself down within a maximum of 5 seconds.

Same for your neighbour.

zeupater

John_Pierpoint wrote: »

If I have a set of panels on my roof and so does my neighbour; how, at noon on a sunny day, does my inverter recognise a power cut and then turn itself off.
Would not it assume that my neighbours panels were creating the mains supply and likewise their inverter would recognise that power was being supplied from my inverter and assume that was the mains power supply?

Even the next morning could one in theory get the whole estate started up by plugging in a small "Honda" generator, to create a cascade of awakening PV installations.:huh:.

Hi John

Just my ramblings ....

I'd guess that your thought is that both inverters would support each other and could continue running, however, both systems track & match grid frequency and voltage ... as soon as major generating plant is disconnected your minute level of generation will disappear into a black hole created by appliances being left on between your systems and the point of disconnection so the voltage will immediately drop out of normal grid supply tolerance conditions and cause both inverters to disconnect .... conversely, if the grid disconnection was just the two systems and there was no demand then both systems would ramp-up the voltage to compete with each other which would also quickly move out of the set tolerances and cause disconnection .... also both inverters would attempt to track the other's frequency and would soon drift out of the tolerance band and disconnect ...

... lots of other reasons but I'd guess that these are the main ones to consider ......

HTH
Z

edwink

spaine wrote: »

Hi edwink,

I've been waiting over 4 months for EON to send me a contract. I've now written to complain after being told its in the post .. another dept needs contacting to send a duplicate, having escalated to mangers and being told I'll get it by email .. still no luck :mad:

Thanks so much for letting me know. It does not suprise me thinking about it. I thought about ringing them then I thought I'd check on here first to see if others are also still waiting to hear!!

Think I'll give them a little more time and then start ringing them. I hate all this number pressing and being held in a queue whilst having to pay for the call on an o8-- number.

Edwink

orrery

EricMears wrote: »

Mine are described as 'self cleaning'...

Mine are specified as self cleaning, but only when mounted at an angle above 20 degrees.

EricMears

orrery wrote: »

Mine are specified as self cleaning, but only when mounted at an angle above 20 degrees.

Our conservatory roof is a lot steeper than 20 deg (more like 45) but the alleged self-cleaning facility is totally useless. No reason to suppose SPs any better

mdynes

The advice is fab on this thread thanks. We arte at the selecting panel stage and it is double dutch to us. Any good sites that rate the panels or do any MSE's have any advice?

orrery

seagull09 wrote: »

Well I'm no expert but the best performing panels would seem to be those from the likes of ....

However, these figures only indicate how much power you get per square meter. A low efficiency panel will be larger (but probably cheaper) to get the required output. You could argue that this is only important if you have limited roof space.

A better measure may be to look at the temperature coefficient. This shows how much the efficiency falls with increased temperature. Typically, this can approach -0.5% per degree C, meaning that you lose almost 25% on a stinking hot day. A lower figure is better.

orrery

seagull09 wrote: »

NOCT °C 45 ± 2
... snip...
Pmax temperature coefficient %/°K - 0,4310

The standard panel rating is likely to be at 25C and I'd guess that it is at this panel ambient that the Normal Operating Cell Temperature is 45C. So you lose 0.431% per degree C rise above this.

It is anyone's guess as to what the cell temperature will be on a stinking hot day, but the maximum specified is usually 85C and I can't think it will be much below that. Normal garden objects get to at least 60C (the temperature at which you just can't hold your hand on for any time) in summer sun so we can assume that the cell temperature will be at least 80C, possibly 85C, so a 40C rise. This would give a 17% reduction in output.