Real-world data request

Hi chaps.

I'm hoping that someone has a system that is something fairly close to:
3kWp (e.g. 2.75-3.25kW)
South-facing (e.g. SSE, S or SSW)
30-degree slope (e.g. 25-35 degrees)
No shading at peak time (e.g. between about 10am to 2pm)


I would like to know the generation rate at various times of the day (say on the hour, every hour) and I would be interested in the hourly generation rate in both full-sun and full-cloud days, along with, if possible, some data which gives an idea of seasonal variation.


So if you have this kind of hourly data, I would be very appreciative if you can help.

Thanks,
F

Our system is 2.88kw and were SSW facing, no shading.
You can see our daily generation since we had it installed at the end of February at 5 minute intervals including weather info here ...

Scobo 2.880kW | Live Output

Here you go.
ET 235 3.290kW

Thanks - that's useful information.

stavtoon said:

Here you go.
ET 235 3.290kW

Click to expand...

This seems a very effective system for its size.....

danesol said:

This seems a very effective system for its size.....

Click to expand...

Probably the local weather.

I noticed the following system in Norwich was performing really well in March, but has been a poor performer recently as many parts of East Anglia have seen unusually dull weather:

> Norwich Power UK 3.840kW <

With 16x240W Sanyo HIT panels and only two days above 20kWh in April - both being in the first few days of the month.

It's not the system; it's the bloomin' weather!
But I suggest watch that system in late summer and early autumn because East Anglia is known for what my mother used to call "Indian summers" with incredible sunshine at that time of year.
The Met Office seasonal weather backs it up too:

> Met Office: UK mapped climate averages <

Please take the time to browse the sunshine hours for spring, summer, autumn and winter and compare different parts of the country.

In autumn, in most years, the systems in the East and SouthEast of the country will be storming ahead those in the West or SouthWest, while the opposite is often true in springtime according to weather data.

Coastal regions nearly always seem to get more than their fair share of sunshine, which is probably why our parents and grandparents used to make off to the coast for their holidays. I was conceived on the Isle of Wight.

FB. said:

............Probably the local weather.

It's not the system; it's the bloomin' weather!

Click to expand...

Couldnt agree more and said a similar statement in another thread...... and its right, you could have the best system in the world, but if the weather is against you as April is with me at the moment, the system will totally under achieve

danesol said:

Couldnt agree more and said a similar statement in another thread...... and its right, you could have the best system in the world, but if the weather is against you as April is with me at the moment, the system will totally under achieve

Click to expand...

Absolutely. Even 20 miles can make a difference.

I'm about 50 miles from the Norwich-based system above.

Since the start of April, I have generated 277kWh with my 15x250W=3.75kW Kinve panels compared to 241kWh from those 16x240W=3.84kW.
That's 18% more power from a system which is 3% smaller and probably 35% cheaper.
Therefore I declare Kinve panels to be much better than Sanyo.

Of course, it's not really true, but it serves to illustrate how we should not make assumptions about performance until either we have lots of data, or unless with give some consideration to the weather.

The thing is here is that there are so many things that can effect a systems performance, not just make of panels or inverter, design of system and quality of installation is of course paramount, different mounting frames can affect performance, I am sure roof coverings could also affect performance, a black slate roof gets hotter than say a fibre cement, so must affect performance, due to location, one system may get more dust on the panels than another.
I know of a system that is under a flight path for aircraft, although not busy and the planes are very high, they produce a vapour trail, and you can watch the performance drop right off, then slowly rise as the vapour clears.
I am sure that grid voltage must affect performance too.
Then there is the weather, and maybe a tiny shading that has not been noticed, like a telephone wire, or you may get more birds around than somebody else.
Also, how hot the inverter is running at, and there are so many more things that could effect performance, although some may be small, over 365 days they can all add up.

Re: Real-world data request - East West Vs South Comparison

Some real world data from two systems less than a mile apart in Worcestershire.

See the post here: http://www.electriciansforums.net/p...-energy-forum/56896-east-west.html#post530998

Hi Gordon, great to have you back posting on the forums.