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  • FIRST POST
    • Kernel Sanders
    • By Kernel Sanders 16th Mar 12, 12:06 AM
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    Kernel Sanders
    Renewables: "talking 'bout my generation"
    • #1
    • 16th Mar 12, 12:06 AM
    Renewables: "talking 'bout my generation" 16th Mar 12 at 12:06 AM
    Please forgive the corny thread title inspired by The Who, but this post on the bloated 'how do I make the most of it' thread prompted me to initiate a new one...
    Hi Everyone,
    I haven't been here for a while, and am interested to see discussion of how much is being generated, rather than what to do with it.
    Originally posted by old grouser
    Well, there was yet another misty and bleak start in North Notts today (Thursday), but my SSW 3.92 kWp system was generating around 3kW for just a few minutes between 12.15 and 13.00, but enough to get the immersion heater hot enough for a shower. It seems to drop below that figure before it reaches 13.55 (optimum orientation). Final figure was just over 14kWh.

    BTW, there was an item about solar generation in Germany on the radio today; you can stream it here:
    http://www.bbc.co.uk/iplayer/episode/b01d2rvn/PM_15_03_2012/
    Just click on the speaker symbol on the left, then drag the time cursor at the bottom to 25mins 30 secs then release.
    Last edited by Kernel Sanders; 19-12-2012 at 7:01 PM.
Page 2
    • mysterons
    • By mysterons 22nd Mar 12, 6:59 PM
    • 131 Posts
    • 112 Thanks
    mysterons
    Meanwhile over on the east coast of Lincs we were forecast mist and fog which fortunately never materialized so instead sun all day gave me an amazing 22.3kwh generated.
    Sorry Welshies
    • Kernel Sanders
    • By Kernel Sanders 22nd Mar 12, 8:07 PM
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    Kernel Sanders
    but it was 11am before mist finally cleared
    Originally posted by EricMears
    Meanwhile over on the east coast of Lincs we were forecast mist and fog which fortunately never materialized so instead sun all day
    Originally posted by mysterons
    I'm in between you two and our mist cleared much earlier, then it was sunshine throughout the day. However, it was also extremely hazy, restricting the final figure to 16.17kWh. Still, generation was very steady and I was in all day so able to use most of it to heat the house although I never had enough for the immersion heater despite it drawing only 2.8kW.
    • Martyn1981
    • By Martyn1981 22nd Mar 12, 8:50 PM
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    Martyn1981
    Meanwhile over on the east coast of Lincs we were forecast mist and fog which fortunately never materialized so instead sun all day gave me an amazing 22.3kwh generated.
    Sorry Welshies
    Originally posted by mysterons
    Hello Mysterons, haven't seen you on here for a while. Are you still generating 'stupid' amounts from your system? Not that I'm jealous, oh no sir, never jealous, not me!

    Don't worry about us Welshies, but please keep the noise down, we're still a little hung over from the 6th Nations. Don't mention the GrandSlam, I mentioned it once, but I think I got away with it!

    Mart.
    • sly_dog_jonah
    • By sly_dog_jonah 23rd Mar 12, 1:14 AM
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    sly_dog_jonah
    A much better week than last here in Cider Country. We only need another 40kWh to hit PVGIS target and we're about 5% under the generation rate needed to hit PVGIS + 25% (101kWh needed in 8 days).

    Importantly, we have a nice high pressure system sittting over the UK this weekend, so fingers crossed for some good generation days. A few 20kWh days would be awesome.

    Shame our BBQ doesn't run on electric
    Clocks go back this weekend, so more of the generation will be in waking hours
    • Martyn1981
    • By Martyn1981 23rd Mar 12, 7:20 AM
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    Martyn1981
    Shame our BBQ doesn't run on electric
    Clocks go back this weekend, so more of the generation will be in waking hours
    Originally posted by sly_dog_jonah
    Good point, generation immediately jumps to 7pm+ so covering almost the whole of the evening peak demand period. Though my ESE panels will only contribute 200 to 400Watts after 5pm BST.

    Clocks go forward, so that means Sunday will be 1 hour shorter, so a little less generation, but I suppose it all balances out with the Autumn change giving us an extra hour!

    Mart.
    • sly_dog_jonah
    • By sly_dog_jonah 23rd Mar 12, 8:08 AM
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    sly_dog_jonah
    Good point, generation immediately jumps to 7pm+ so covering almost the whole of the evening peak demand period. Though my ESE panels will only contribute 200 to 400Watts after 5pm BST.

    Clocks go forward, so that means Sunday will be 1 hour shorter, so a little less generation, but I suppose it all balances out with the Autumn change giving us an extra hour!

    Mart.
    Originally posted by Martyn1981
    I think you must be half asleep Mart The sun doesn't shine at 2am in the morning so the clocks moving forward or backward don't affect the generation whatsoever.

    Cracking morning here, not a cloud in the sky and generating 1.9kW already.

    I think I might change my forum name to the Sundance Kid
    Last edited by sly_dog_jonah; 23-03-2012 at 2:32 PM.
    • Martyn1981
    • By Martyn1981 23rd Mar 12, 9:29 AM
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    Martyn1981
    I think you must be half asleep Mart The sun doesn't shine at 2am in the morning so the clocks moving forward or backward don't affect the generation whatsoever.

    Cracking morning here, not a cloud in the sky and just about to generating 1.9kW already.
    Originally posted by sly_dog_jonah
    But the day is an hour shorter?

    Damn, not a single bite! I thought I might get one or two of you with that one. Should have held off till the 1st April?

    Weather here is stunning, and the forecast is for solid suns till the end of the month, apart from the 25th and 31st which are sunny with a little cloud. Of course by tomorrow those forecasts will have changed to thunderstorms!

    So it looks like Spring arrived spot on cue.

    Mart.
    • sly_dog_jonah
    • By sly_dog_jonah 23rd Mar 12, 2:39 PM
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    sly_dog_jonah
    Despite the clear skies today, the output has been about 10% lower than our previous record due to the haze in the sky. I didn't realise such thin high cloud could have a significant impact, but can't really grumble as we've made 17.8kWh (and are still generating 1.4kW) and I reckon we should make about 19-20kWh by the end of the day (versus 21.3kWh recorded on Monday).
    • Kernel Sanders
    • By Kernel Sanders 24th Mar 12, 1:21 AM
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    Kernel Sanders
    but can't really grumble as we've made 17.8kWh (and are still generating 1.4kW) and I reckon we should make about 19-20kWh by the end of the day
    Originally posted by sly_dog_jonah
    No you can't, I only made 11.17kWh all day
    I'm here for just a few days' intensive motor insurance tuition so as to avoid another huge blunder. Please bear with me!
    • Kernel Sanders
    • By Kernel Sanders 25th Mar 12, 12:21 AM
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    Kernel Sanders
    This morning actually (sunny and bright) was interesting and confirmed to me that a single MPPT inverter is not great when panels facing different directions. Nice full sun on my SE panels, should have seen about 500-600 watts from those, plus maybe 100-200 from those not yet in sun. Instead the TOTAL generating was 300w. It does explain why I'm losing so much on a day like this, because it's midday before I'm seeing decent figures, and of course by 2.30 p.m the SE panels are then doing the dragging down.
    Originally posted by seagull09
    I was told by my installer that I needed two strings because there was a maximum output on each one (10 amps?) Is this the reason you thought you only needed one string? If you are on the higher rate of FiT then it would pay you to have an additional small inverter installed, but would this affect your eligibility? If they didn't advise you properly, could you launch a claim against your installer for loss if FiTs?
    Last edited by Kernel Sanders; 25-03-2012 at 12:23 AM.
    I'm here for just a few days' intensive motor insurance tuition so as to avoid another huge blunder. Please bear with me!
    • EricMears
    • By EricMears 25th Mar 12, 11:39 AM
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    EricMears
    'Jokecast' strikes again !

    Yesterday forecast was for slight mist clearing by lunchtime. In fact we had major mist clearing by lunchtime but it was well into the afternoon before it really cleared.

    Today's forecast was exactly the same - but I was up to a kw by 9am (8am in 'old money') which first happened at noon yesterday.

    Sometimes I wonder why I bother looking at forecasts !
    NE Derbyshire.
    4kWp S Facing 17.5deg slope (dormer roof).
    • EricMears
    • By EricMears 25th Mar 12, 1:57 PM
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    EricMears

    Strange day today, looks very bright out there but output is lower than yesterday for same time of day (allowing for 1 hour later clocks movement).
    Originally posted by seagull09

    Strange here too ! Output peaked (3kw) at (alleged) 12:00 (i.e. an hour and a bit before noon), dipped half a kw but is back to 12:00 reading now (just before 2pm BST). Pretty sure that was high level broken cloud around (proper) noon but wasn't actually staring upwards at the time. Extrapolating curve I might have got to 3.3kw given clearer skies.

    Notice your 600 litre rainwater storage mentioned in signature. Rainfall less reliable in E Midlands - I need 4.4 cu metres to ensure I can keep flushing lavatories through several rain free weeks. Never run out since I upgraded from 2.4 cu m though I have been quite close a couple of times.
    NE Derbyshire.
    4kWp S Facing 17.5deg slope (dormer roof).
    • EricMears
    • By EricMears 25th Mar 12, 4:04 PM
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    EricMears
    Wow, that's 4400 litres - not sure I'd even have room to store all that! Excellent idea though to use it for flushing, it's the next thing I'll look at doing once roof sorted out, as I'm on a meter. I suspect half what you have would be adequate here given the, erm, slightly higher rainfall.
    Originally posted by seagull09
    Afraid this is way off topic - sorry folks.

    Yes, it's 4 x 1 tonne transitanks in basement plus 2 x 200litre storage tanks in loft.

    Lavatory flushing is biggest single use of mains water and it's one of my hobby-horses that it's a profligate waste of resources to purify water to drinking standards just to flush it. It accounts for about a third of domestic water supplies so any metered consumer could immediately knock a third off water bills (and sewerage bills too if you discharge to a public sewer - we don't).

    We usually have to pump approx 100 litres per day from basement to loft - and of course it's a bonus to do that with free electricity - so could withstand six weeks of drought which seldom happens here.
    NE Derbyshire.
    4kWp S Facing 17.5deg slope (dormer roof).
    • sly_dog_jonah
    • By sly_dog_jonah 25th Mar 12, 10:50 PM
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    sly_dog_jonah
    Well it's been a fantastic week in cider country: 108.7kWh in the last 7 days. Only 45kWh needed to beat PVGIS by 25% with 5days to go and a great forecast for the next few days. The haze this weekend has constrained the output compared to our new record last Monday, but can't complain as the clouds have been few and far between.
    • Kernel Sanders
    • By Kernel Sanders 26th Mar 12, 12:15 AM
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    Kernel Sanders
    Same experience for me. Despite beating Tuesday's previous record by nearly 3 kWh, I was struggling to exceed 3000W at lunchtime. However, sustained low voltage meant that I was able to have my immersion heater on up to a half hour after my optimum orientation, which is now 14.45, so I did that for free whilst generating only 2900 - 3000W for that period.
    So, could the problem have been ozone?
    I'm here for just a few days' intensive motor insurance tuition so as to avoid another huge blunder. Please bear with me!
    • sly_dog_jonah
    • By sly_dog_jonah 26th Mar 12, 8:58 AM
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    sly_dog_jonah
    Same experience for me. Despite beating Tuesday's previous record by nearly 3 kWh, I was struggling to exceed 3000W at lunchtime. However, sustained low voltage meant that I was able to have my immersion heater on up to a half hour after my optimum orientation, which is now 14.45, so I did that for free whilst generating only 2900 - 3000W for that period.
    So, could the problem have been ozone?
    Originally posted by Kernel Sanders
    I believe hazy sunshine is just caused by very thin high cloud. Ozone blocks UV light, but I don't believe that part of the spectrum is captured by PV.

    Today the blue sky looks much bluer in cider country and our output is already around the 2kW level, which is much closer to our previous record day at this time of day (ignoring British Shorts Time).
    • EricMears
    • By EricMears 26th Mar 12, 10:39 AM
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    EricMears
    Yesterday was my second best ever day at 19.93 kw (the cloudy spell at noon held me back from 20kw barrier !). The better day was on 4th Sept when I got to 22 and we're now less days after equinox than that day was before the autumn one. You'd think the last few days in August might have been better still but they were mostly quite cloudy.
    Last edited by EricMears; 26-03-2012 at 11:45 AM.
    NE Derbyshire.
    4kWp S Facing 17.5deg slope (dormer roof).
    • EricMears
    • By EricMears 26th Mar 12, 11:39 AM
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    EricMears
    O/T: Thanks for the reply EricMears regarding your rainwater system - presumably you have to keep the loft rainwater supply to WC completely separate from mains water, do you have a diverter valve for if you run out of rainwater?
    Originally posted by seagull09
    Still O/T - but "we've started so we should finish" (else we'll get a string of PMs asking for details ).

    The WCs are supplied from the loft tanks - as used to be the norm in the 'good old days'. Anyone who has ever needed to use a lavatory during a water mains maintenance day will share my anathema at the modern trend of using a mains feed for WCs !

    The tanks have a perfectly ordinary ballcock arrangement for filling with mains water - except that the in-line isolation valve is almost always turned off. An additional feed to the tank from pump in basement has a level alarm to alert operator to switch off pump.
    Last edited by EricMears; 26-03-2012 at 11:43 AM.
    NE Derbyshire.
    4kWp S Facing 17.5deg slope (dormer roof).
    • KevinG
    • By KevinG 26th Mar 12, 11:41 AM
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    KevinG
    Yesterday was my best day since 10th August. 11.2kWh, 2kWp, SSE facing, 37 degree pitch, north Sussex.
    • sly_dog_jonah
    • By sly_dog_jonah 26th Mar 12, 8:01 PM
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    sly_dog_jonah
    Another near-record day in Cider Country, with a 20.8kWh generation recorded today.

    Monday last week remains our record and had a slightly higher performance curve at each stage of the day, despite the sky being just as clear as I recall (in fact there were some lunchtime clouds at lunch time last week too). My theory is that the wind last week was cooling the panels more to help them generate power more optimally.

    I've started calculating a 7d,14d & 30d rolling average on my spreadsheet. The 7day is currently running at 15.5kWh and 14 day got into double figures yesterday for the first time, while the 30day rolling average hit double figures on Friday. According to PVGIS, our estimated average generation in March should be 7.86kWh/day, and should peak at 12.6kWh/day in June.

    We've already exceeded PVGIS estimate for March by 14% (with 5 days to spare) and only need 26kWh more to beat it by 25%. Considering the rubbish week we had here two weeks ago, I'm pretty chuffed the monthly performance is still looking so good.
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