Renewables: "talking 'bout my generation"

edwink

Poor old Oscar - watcha gonna do with all that snow!!!

First suggestion - build a huge snowman. :rotfl::rotfl: :rotfl: :rotfl:

Anyone else got any suggestions for Oscar?

Edwink

k66

Poor old Oscar - watcha gonna do with all that snow!!!

First suggestion - build a huge snowman. :rotfl::rotfl: :rotfl: :rotfl:
Second suggestion - build an igloo.

Anyone else got any suggestions for Oscar?

tunnel

Oscargrouch wrote: »

Question:
Who posted that they had left a heater on, and it had cost them a fortune some time back? Own up, 'I am Caine, I will help you'.

Guilty as charged.:(

legoman62

1.97kWh today.

Tomorrow is last day for FITs payment in 1st quarter.

Only need 60kWh to match same period last year.

Anyone fancy a whipround?:rotfl:

Oscargrouch

legoman62 wrote: »

1.97kWh today.

Tomorrow is last day for FITs payment in 1st quarter.

Only need 60kWh to match same period last year.

Anyone fancy a whipround?:rotfl:

You are not alone; I need to average 7.2kWh per day for the next 9 days to equal last years 1/4

sly_dog_jonah

Even with no snow in Cider Country rest assured the performance is as pants as elsewhere in the country: 1.1kWh today. No longer on target for PVGIS-Classic in Feb :-(

jackieblack

Despite terrible generation for the last few days (0s and 1s only ) I am surprised to discover weare on 40% of target for Feb.

Finished FIT quarter on Tuesday, only 79% of figure for same quarter last year but up 18% on the previous year so guessing that's not unreasonable really.

Dave_Fowler

Over the past few weeks of very varied weather I have been comparing the outputs from my two solar PV systems. System 1 is a conventional 16-panel set up with two strings of eight panels wired in parallel to a single MPP inverter. System 2 has 12 panels, each with its own power optimiser, wired in series to the inverter (not a conventional MPP tracker inverter). System 2 is monitored on-line where the output of the inverter and each of the panels is shown.

First observations show that System 1 starts up earlier in the morning than system 2 and produces a few Watt hours before system 2 starts. Checking on-line I find that not all the power optimisers start up in low light. The specifications say that there must be 8 optimisers in a string before there is an output.

Once system 2 is awake, the optimisers do appear to help during cloudy days. Currently (100% overcast) system 1 is producing 403 Watts and system 2 is producing 420 Watts. This 5% difference continues (and slightly increases to 8%) as the power output increases right up to around 1800 Watts. From this point, there is a a good view of the sun and system 2 output falls behind system 1 due to the roof angle. I will have to wait until noon in the middle of March for the difference in the roof angles to be eliminated.

The effects of snow has been interesting. When the snow started to slide off the top string of system 1 (about 20% of the top 8 panels was visible), system 1 'woke up'. The power optimisers of system 2 did not wake up until most of the snow was off the panels.

System 2 has 2 panels in landscape format and the other 10 are in portrait. As the snow slid off, the optimisers on the landscape panels woke when there was about 80% of each panel uncovered (there was a 20% coverage along the lower long edge). The portrait panels needed virtually all the snow cleared from their lower ends before the optimisers worked. I suspect this is something to do with the internal connections of the solar cells.

One experiment I was able to do on system 2 was to remove the snow from individual panels (I can easily gain access to system 2 panels) and watch the effects on-line. When I removed the snow from 6 panels, the inverter was able to start up and produced an output of about half of what I would expect from the total 12 panel array. When the eight panels in the top half of system 1 were free of snow I was still only getting a few hundred Watts - the other eight snow-covered panels were 'shorting out' the working panels.

The overall effect of the dull weather and then the snow on the two systems has almost cancelled out. So far in February System 1 has produced 39kWh and system 2 has produced 37kWh. Half of the month's output has been produced during 3 days - free hot water on these days.

Dave F

Martyn1981

Dave, really interesting. It won't make much of a difference, but are your numbers from inverters or TGM's?

My SB2500 under reports about 1%.
My SB1200 under 3%
My SE2200 over 1%

Still don't want to say it too loud but my shaded WNW with power optimisers appears to be generating as if unshaded. That doesn't really make sense, perhaps it's the difference in efficiency compared to the SB's, but I'm not complaining.

Looks like today will close on about 10kWh's. Nice. And a very good long term forecast too, wonder if this one will be right.

Mart.

Dave_Fowler

Martyn1981 wrote: »

Dave, really interesting. It won't make much of a difference, but are your numbers from inverters or TGM's?

My SB2500 under reports about 1%.
My SB1200 under 3%
My SE2200 over 1%

Still don't want to say it too loud but my shaded WNW with power optimisers appears to be generating as if unshaded. That doesn't really make sense, perhaps it's the difference in efficiency compared to the SB's, but I'm not complaining.

Looks like today will close on about 10kWh's. Nice. And a very good long term forecast too, wonder if this one will be right.

Mart.

Hi Mart,

All the readings are from TGMs. The system 1 inverter is in the loft and not very accessible.

I've now got all the TGM output pulses connected to displays in my office and have synchronised the readings to the TGMs. There has been no discrepancy between the readings on the TGMs and the counted pulses. I can now get an accurate reading to the nearest Watt-hour for both systems rather than to the nearest 1kWh which is the reading on the TGM of system 1.

The combined total for today from the two systems is approaching 6.5kWh. The sun has been reluctant to shine today.

Dave F