Members Daily Readings with graphs

[danesol]

Location:- North West
Azimuth:- Facing nearly direct South with 30degree pitch...
Environment:- Total shade on both sides - morning due to buildings, early evening due to adjacent trees
Generation cycle:- Fully kicks in fully at 9.30'sh and in full shade at 4pm, due to the trees
System:- 12 x Sanyo 240HiTs / SMA 3000HF ( 2.88kw)

Date:- 25 March 2012
Weather:- Slightly misty
Max Temp:- 21deg
Peak - just over 2.4KWp
Most generated between 10am & 3pm

Total generated - 13.52kwh

 

[MorganPVI]

26/03/12	20.8
25/03/12	19.9
24/03/12	18.4
23/03/12	16.8
22/03/12	13.8
21/03/12	13.4
20/03/12	15.5
19/03/12	20
18/03/12	10.3
17/03/12	6.9

South, 3.76kwp Sharp 235w, Dielh 3800 inverter

 

[Scobo]

2.88kw system, SSW facing, full sun all day, 15.5kwh generated.

 

[danesol]

Date:- 27 March 2012
Day yield:- 14.21 kWh

 

[series530]

Take a look here at any time

33AFGR 3.500kW

Bear in mind that my system is SSW, on a steep roof and suffers a fair bit of shading.

 

[GaryM]

Here's mine GaryM 4kWp 4.000kW

Manchester area, 4kWp (16 x JA Solar 250W mono's), Fronius IG TL 3.6, south facing, 28 degrees, no shading.

 

[Gary K]

3.84 kw system, Norwich. fraction East of south
Almost 180kwh in last 9 days
here

 

[finchy]

Very good post, hopefully all this positive chat about generated power will make the customers sitting fence pull their figures out.

 

[FB.]

Hopefully my signature now contains all you need to know about my system.
:rockon:
.

 

[Mozzerr]

Location:- North Shropshire
Azimuth:- 10 degrees East of due South with 30degree pitch
Environment:- No shade
System:- 16 x Suntellite 250 Black. SMA 4000TF ( 4.0Kw )

Date:- 27 March 2012
Weather:- Slightly hazy all day
Max Temp:- 18 degrees

Today's Graph

 

[Oliver Par]

Location: West Wales
Facing: South
Roof angle: 37 degrees
System: 3.5kW 14 panels

27/03/12 17.94
26/03/12 18.00 (2962 W max)
25/03/12 17.52

All three days, sunny and bright, but hazy in the distance. Quite honestly I was a little disappointed with yesterdays reading as I thought it was clear

 

[firemanowl]

Not had anything to do with solar but what would you class as good performance?

 

[FB.]

Not had anything to do with solar but what would you class as good performance?

That's very dependent on the location, the facing, the roof angle, the panel type, any shading issues and even how two different installers interpret the shading penalty for the SAP calculations and how they lay out the panels to optimise the bypass diodes when shading occurs.
Nowadays, most systems should be outperforming an accurately-estimated SAP by 5-15%, so I'd say:

Adequate performance would be meeting the SAP target or slightly exceeding it by up to 5% on a cumulative basis.

Satisfactory performance would be generating 5-15% more than the SAP target on a cumulative basis.

Good performance would be generating 15-25% more than SAP target on a cumulative basis.

Very good performance would be more than 25% above SAP target on a cumulative basis.

Note that I say "cumulative basis" meaning "all generation since the system was installed" because from day-to-day, or week-to-week, or even month-to-month, the weather can be very variable. But over many months it tends to average-out.

As a very rough guide, each kW of panels, with a typical unshaded 30-45 degree roof, in Central England, would be expected to generate about the following kWh per year, per kW of panels, to meet the SAP target, based on their facing:

675kWh for East or West
775kWh for East-South-East or West-South-West
825kWh for SouthEast or SouthWest
875kWh for South-South-East or South-South-West
900kWh for South

So a 4kWp system, facing South, will have a SAP target around 3600kWh.
Therefore,
"adequate" would be 3400-3800kWh per year
"satisfactory" would be 3800-4100kWh,
"good" would be 4100-4500kWh
"very good" would be more than 4500kWh

 

[FB.]

Hopefully my signature now contains all you need to know about my system.
:rockon:
.

Hopefully there's enough resolution and not too many typo's in the attached table, which suggests DAILY expected generation, which I just put together for when people ask "what should I be generating?"
I take no responsibility for any errors or omissions in the table, or for any use to which it may be put, but to the best of my knowledge and ability, it is approximately correct to SAP equivalent generation statistics.

Just multiply the system size (kWp) by the number given under the appropriate roof pitch/compass facing.

Light shading might lose 10%.
Moderate shading might lose 25%
Heavy shading might lose 50%.

Shading effect can be difficult to predict, with some inverter/panel combinations coping better or worse than others.
An East-facing system might not be troubled by shading after lunchtime. A West-facing system might not be troubled by morning shading.
Peak output will generally be when the sun shines directly at the panels; early morning for East-facing, mid-morning for SE-facing, lunchtime for South-facing, mid-afternoon for SW-facing, late afternoon for West-facing.


My 3.75kWp system, facing SE, 40' pitch, no shading, would be expected to be generating 2.0kWh per kW of installed capacity in March or 2.8 in April, so as today is close to the borderline between March April, if we split the difference between 2.0 and 2.8 - and call it 2.4.
Multiply the 2.4kW with my system size (kWp) of 3.75 to give an estimate of about 9kWh per day at this time of year.
This could be more than halved to below 4.5kWh of generation on cloudy days at this time of year, or more than doubled to over 18kWh of generation on sunny days.

 

[Scobo]

Not quite as good today but still pretty decent.
Some light cloud late afternoon.
13kwh generated.