More to the point, the inverter is showing the very princely value of 8.3kWh for the total generated today. This, I am very happy with indeed.
I have done a bit of rummaging around the t'interweb, and have found a great web page on the met office showing the average sunlight (amongst other things) for Blackpool over the years 1981 - 2010, broken down into months.
| http://www.metoffice.gov.uk/climate/uk/averages/19812010/sites/blackpool.html |
Note this is not all daylight hours - this is hours of actual direct sunlight, excluding hours when the sun is behind cloud. Very useful for solar panel calculations... I have crunched this with the predicted yearly total kWh to give the predicted monthly average kWh for each month. I've then broken each month down into days simply by dividing by the number of days in the month. For August, I should be generating an average of 5.98kWh per day to achieve the predicted monthly average of 185.39kWh. At 8.3kWh, this is 139% of the predicted average. I know this is only one day, but we are at the end of August, and I would expect this to be the worst end of the month for sunlight. The beginning of the month would have yielded higher values.
If I were to (probably quite foolishly) extrapolate this increase across the whole year, my revised predicted total kWh generated would be 1645 x 139% = 2286kWh. I think it is probably a bit rash to be expecting this much, but I am cautiously looking sidelong at 2000kWh... Today's actual v predicted kWh does seem to correlate very nicely with the "about a third more" quotes I was getting regarding these 3rd gen HIT panels. Only time will tell....
The boss bloke from the solar panel installation company has been today to sign off on the rig so I can apply for the feed in tariff (and so he could collect his cheque...!) I have posted off the FIT forms, and he tells me it takes about 2 months for them to process them. They backdate the payments to the commissioning date, so I don't lose any payments, they just make you wait for it.
The official documented maximum supply of my 8 panel array is 1.92kW (each panel is actually only 240W, not 250W), although it's referred to as a 2kW array.
So how much of that maximum did I see today? Today has been a bit overcast, with some broken cloud and hazy sun. You can see on the little graph on the photo there's only a narrow peak in the middle couple of hours around lunchtime when I'm getting the maximum out of the system. Although the peak in the middle could have been wider, it's just that the broken cloud cover today meant it wasn't maintaining it's maximum as long as it could have. I looked at the screen around 1pm. Whilst the sun was behind hazy cloud, it was hovering around 1.6-1.7kW. When the sun popped out of the broken cloud and the array received direct sunlight, the meter peaked temporarily at 1.90kW. I'm guessing that this is as high as it's going to get in August - I assume it could only hit its theoretical maximum at midsummer (end of June) when the sun is at the optimum angle in the sky.
Update on the drop in voltage on being connected to the grid: Rubbish. This was just me being a plantpot (not the first time). What actually happened is that whilst the bloke was tinkering with initialising the inverter, a good 10-15 minutes passed between him connecting the array and the inverter finally getting connected. It was during this 15 minutes that the voltage dropped off, simply due to the sun dropping in the sky. As described in the paragraph above, it has hit very close to its theoretical maximum at times.
One final note that is worth making - this aurora inverter runs practically silent. I had to put my ear onto it to make out a faint hum.
So that's that... Feel free to ask q's - the future updates will be less wordy, I'll post actual vs predicted values at regular intervals.
8.3kWh sounds very good!
ReplyDeleteIs there any way to show from the inverter if during the day you are producing an excess amount of power, thus making a modicum of profit?
Also, do you still have your old meter in place? If so, I'd take a meter reading and let your leccy company know you've got panels, because if you're paying a flat fee each month you'll end up overpaying. This happened to Hannah and me once upon a time - when we moved from Clifton Drive to St David's Road we got a cheque from them for £800 due to overpaid bills!
£800! Yeowch! That's a huge overpayment!
ReplyDeleteI've applied for the feed-in tariff with the same company that supplies our leccy, so they'll know very soon that we have panels, since they're the ones who'll be paying us for what we generate.
Yes the old meter is still in place - this now measures just the electricity that we buy in from the grid. There's a separate meter that is installed with the panels that measures just the solar-generated leccy. The great thing about the feed-in tariff is that I still get paid 14.9p for *every* kWh I generate, even though I use some or all of it myself.
There's a more comprehensive description of how the feed-in tariff works on my first blog page (where it all began).
Excellent stuff! Do you know if you've been using all/some/most of the kWh you've been producing so far?
ReplyDeleteUnfortunately there's no meter installed to tell me how much of the solar-generated leccy I'm consuming myself so I'll never have a definitive answer to that. The best answer will be to compare this year's leccy bills to the same time period last year - the drop in consumption will be approximately equal to the amount of solar-generated leccy I've consumed myself.
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