Pink Duck
Active Member
They give their main expectation plus the wide 10% and 90%tile range, which mostly depends on decent enough prediction of cloud cover, that our own local meteorologists seem to struggle with too.
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Solar Panels UK - is it worth it?
- Thread starter jdwuk
- Start date
WannabeOwner
Well-Known Member
Yes. That probably explains it, thanks.
I find that that varies a lot, day to day, depending on their confidence. Sometimes it tracks very close to the prediciton,. sometimes there is a vast uncertainty.
I ought to do some checks to see how often the actual was outside the 10%-90%tile ... I have that data going back a year, maybe two ... and at several points during each day (as the "uncertainty" usually reduces as the time approaches).
Finally got this all set up and configured the PW to export everything. Exported about 4.7kWh during the saving session today (17:30-18:30), so about £10 worth of Octopoints at a net rate of about £2.15. Not bad for the first outing. Impressed that all I have to do is set the export rate for the saving session in the app (and remember to set it back afterwards).
phil4
Member
I don't believe so, it's never been all that accurate if I'm honest. Not just this week or winter. Basically unless it's perfectly clear day in summer, or a perfectly cloudy day anytime, it's out.
phil4
Member
If they measure export, then whatever is closest to your energy providers bill... in my case that's the PW figures which are the lowest of inverter (solis), zappi and the powerwall.
It’s not as simple as that because the solar is not always 100% exported and most days I also export excess battery storage at the end of the day. So my solar production figure will rarely be the same as the energy exported to the grid.
I’m putting figures in a spreadsheet to get a rough idea of payback timescales. The export figure I do take from the Octopus Energy stats so I know that’s accurate. It’s the solar production figures that I’m now not sure of. I have been using the Tesla figures but not sure if the Solaredge figures are more accurate.
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phil4
Member
You'll never really know then... and for what it's worth not sure it matters, there's conversion losses when charging a batter then discharging it. Losses on the line, the fact that changing voltage (as needed to import/export etc), changes the wattage, couple that with devices that measure at differing frequencies (every 5 mins isn't as good as every 10 seconds, isn't as good as every second), and with CT clamps that may be inaccurate. You're on hiding to nothing trying to work out which is "right". The reason I mention the closest to octopus figures is because if exporting, that's what matters. If you're powering the house then exporting later, then not sure anything other than export matters. How much you generated and or used doesn't really need to be accurate?
Makes sense. I’ll just stick with what I’m already doing. As you said it doesn’t need to be ultra accurate.
Pete UK
Member
Lunar Panels?
Between 1020pm and 0030am I was generating 1w from the full moon on my East facing array of 8 panels (none from the others, unless I was asleep by then). Anyone else get this?
Made me chuckle.
Between 1020pm and 0030am I was generating 1w from the full moon on my East facing array of 8 panels (none from the others, unless I was asleep by then). Anyone else get this?
Made me chuckle.
Maybe we could have a whip-round and see if Elon would throw some mirrors up into orbit for us?Lunar Panels?
Between 1020pm and 0030am I was generating 1w from the full moon on my East facing array of 8 panels (none from the others, unless I was asleep by then). Anyone else get this?
Made me chuckle.
there was a development for panels to utilise water droplet friction when raining 
www.theguardian.com
Rain or shine: new solar cell captures energy from raindrops
New device is designed to prevent power output plummeting when the sun isn’t shining – but practical application is still some years off
www.theguardian.com
There was one that tried to use the temp differential between the front and back of the panels to achieve something too. Also looked meh.there was a development for panels to utilise water droplet friction when raining
Rain or shine: new solar cell captures energy from raindrops
New device is designed to prevent power output plummeting when the sun isn’t shining – but practical application is still some years off
AndrewGR
Member
UK electricity meters must be accurate to within +2.5% -3.5%. I suspect that modern meters are a lot more accurate than that. This report looks at faults in meters submitted for testing - not likely to be representative of modern meters which haven’t been tampered with.
Pete UK
Member
RedMod3
Member
Congratulations of your LunarPanels - do you intend getting more to harvest more moonlight?Lunar Panels?
Between 1020pm and 0030am I was generating 1w from the full moon on my East facing array of 8 panels (none from the others, unless I was asleep by then). Anyone else get this?
Made me chuckle.
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Drew57
Active ember
I gave his post a like but a lunar tick would have been more appropriate..
