OT Milestone.

[harry]

First solar panel array (3.85Kwhp) has just clocked up 30,000Kwh in 2,220 days

[Tim Streater]

What does 3.85Kwhp mean?

[Chris Hogg]

He means 3.85Kwp. In previous post here some while ago*, he said his first panels were 3.88Kwp. It tells you something about Harry that he doesn't seem to know the difference, although you probably knew it anyway.

The figures he's just put up give a capacity factor of 14%, and he obviously thinks that's good, otherwise why post them. That says it all, really!

*Harryagain 13/08/2011 13.27 Solar PV Panels: manufacturer?

[Tim Streater]

Well as a matter of fact I don't know what 3.85Kwp means either, unless that is the peak or maximum capacity of the device.

[Fredxx]

Isn't it obvious?

Any help here?

:-)

[Chris Hogg]

It's the power the panel will produce under optimum conditions, i.e. full sunshine. The boiler plate power, if you prefer.

[Andy Burns]

yes, it's the peak output, under specific test conditions.

Under £4k worth of electricity in over 6 years, and he rips us for £2600/year

[543dsa]

Kwh peak output.

[Ian Jackson]

In message , 543dsa writes

Can you HAVE kWh peak?

kWh the product of power and time. With solar power, the power output will vary with time, so the accumulation of kWh will be the summation of an infinite number of instantaneous tiny individual 'samples' of kW.

While a solar panel will certainly have a maximum rated power output, this has nothing to do with time (ie hours).

Or am I just confused?

[Chris J Dixon]

No, the "h" is wrong, as is the capitalisation.

It should have been written as 3.85 kWp.

Chris

[543dsa]

Yes, but Kwp makes more sense.

Yes, but since you can have peak output, there is a sense in which you can have peak output over time, say as the sun starts off off axis, moves to at right angles to the panel and then at off axis by the same amount the other way, too. Sort of a rough indication of how much off axis affects the power it produces.

It is to some extent with the variation of time with the angle of the sun around the right angle to the sun.

Not really.

[Tim Streater]

So your 14 or 15% load factor is based on what some level of constant sunlight for 24 hours each day would generate. I expect harry would say, well over a year, the average daylight hours is 12 so that gives

30% or so load factor.

Of course I still maintain that renewables should be responsible for 24 hour a day constant production.

[Tim Streater]

Kwh peak output has no meaning. Try again.

[Tim Streater]

No, it's 543dsa who is confused. It's like saying your ship's speed is

10 knots per hour.

[The Natural Philosopher]

Oh dear.

[The Natural Philosopher]

No. 543dsa is.

[The Natural Philosopher]

No

Weasel

Oh dear. Stop digging

[Chris Hogg]

Yes. Harry claims 30,000 kWh in 2,220 days, or 2,220 x 24 = 53280 hours. The maximum output in that time is 3.85 x 53280 = 205128 kWh, which gives a load factor of 30,000/205,128 = 14.6%

He might say that, but that's not what is meant by 'load factor'(aka capacity factor), which is always calculated with reference to the maximum possible output. It's not calculated just using hours of daylight, any more than calculating the load factor of wind turbines is done for only when the wind blows.

In fact despite my negative comments on Harry's panels, he's doing better than the national average for big solar farms, which is about

9% IIRC.

[harry]

Typo. It should be Kwp. (p = peak) Maximum theoretical power output. Almost never achieved in UK

[The Natural Philosopher]

Which is very interestig since if he is living in the UK the insolation at BEST gives a 10% capacity factor - i.e. the peak to mean ratio of the annual insolation is 10:1

Fromn sheffield uni via gridwatch

mysql> select max(solar) from day where solar < 100000 and timestamp like '2017%' -> ;

+------------+ | max(solar) | +------------+ | 8760 | +------------+

So peak 2017 output is 8.7GW

mysql> select avg(solar) from day where timestamp like '2017%';

+--------------------+ | avg(solar) | +--------------------+ | 1185.0125496602625 | +--------------------+

what is the average over the max?

13.5%. +-

However it is unlikely that that is the actual *capacity factor*, because thet would imply that ALL the solar panels in the UK were achieving nameplate output when they managed to deliver 8.7GW.