Renewables: "talking 'bout my generation"

jimjames

Best day of year so far. 19kWh so 6.3 Os

ajbell

6.1 Os today.

Martyn1981

EricMears wrote: »

That' a considerable over-simplification hence I'm afraid just plain wrong.

If you say so. But with the specs of a local sample system, combined with local weather, and all systems registered with the DNO, OFGEM and FiT provider, I suspect it's you that's got it wrong, and the industry that has it right.

EricMears wrote: »

If one knows the total kWp of the 244 individual sites and the total installed kWp over the whole country

One would.

EricMears wrote: »

244 isn't a very large number compared with the hundreds of thousands (millions even ?) of installations over the country.
The 244 are probably unchanged from year to year whereas the whole country adds a few more every year. Newer installations will probably use more efficient panels.
A very large sample population randomly sampled would probably include a 'fair' share of optimally & non-optimally aligned panels. A small sample population is unlikely to do that accurately.

244 sounds reasonable, it doesn't have to reflect the number of installs, just a national spread.

New installations ..... so what, they will just be estimated from local samples, just like the rest.

Efficiency is also irrelevant, as efficiency simply reflects the size of the system relative to the kWp. A 4kWp system may be 25.6m2 or 19.4m2, but it's still registered as a 4kWp system with generation proportional. Different generation 'styles' of different panel technologies can simply be taken into account (if relevant) based on UK imports and sales.

Sampling would not have to include every local orientation and pitch, as these could be partially averaged out, but also calculated for based on the performance of the sample system, time of year, and weather through the day.

EricMears wrote: »

I'd hate to even try and estimate the sources of error in such a calculation but would expect it to be at least 10%. The only real hope is that there are likely to be errors in both directions so they might balance out to some extent.

If you say so, but 10% seems very high given the level of knowledge and the number of years of generation already to fine tune calculations, and to review estimates against reported metered annual generation figures.


BTW, just short of 4 O's yesterday, so a very nice run this month so far.

EricMears

Martyn1981 wrote: »

I suspect it's you that's got it wrong, and the industry that has it right.

Again, you're quoting out of context ! "The industry" does NOT attempt to compare two individual properties using the simple kWh/kWp ratio. Trying to do that has been my only ever criticism of that ratio.

countryman_2

Well, all I know is I was just a shade off a Maiden yesterday at 5.91 O's ...

Markj1110

5.61 O's yesterday, A HAWAII, again. :T

ASavvyBuyer

A bit cloudier yesterday afternoon, just 3.585 O's for yesterday.

Good start for today though with the morning sun in the east bouncing off the clouds this morning; produced over 1kWh already from our West facing panels.

rugbyleaguesmate

4.31os 29kw today, 290kw for the month and 2.39mw since install a lot of 2s and 9s there

Merlin139

Started great, then a roller coaster of a day!

Ended with a Magnum! of O's

legoman62

Poor day on the E. coast today.......He thinks. 2.4 O's:D