Welsh community wind project looking for investors

Post by **kenneal - lagger** » 12 Nov 2016, 16:43

The Awel wind turbine project in south Wales near Swansea is looking for investors of between £50 and £100,000.

PS_RalphW · Post by **PS_RalphW** » 30 Mar 2017, 07:31

The turbines have been producing for 2 months now, and have passed 2.2MWh, well ahead of projections. This in spite of them still being in the testing phase with some down time.

My 0.167 % share in the total project cost has already offset my anticipated annual consumption of electricity. My annual dividend cheque should pay for by electric bills and some of the heating costs as well.

emordnilap · Post by **emordnilap** » 30 Mar 2017, 09:54

Jealousy, Ralph. This type of scheme should be common. Is it possible to show a 'rate of return' on your investment?

PS_RalphW · Post by **PS_RalphW** » 24 Jan 2018, 20:05

The first year is nearly up, and it looks like the turbines have come in about 9% under their P50 annual production at capacity factor of about 27.6 %. (11.4 vs 12.4 GWh)

The standard deviation for annual wind resource at a site is usually quoted as 6% so production is 1 1/2 standard deviations down. Hopefully better next year.

Post by **clv101** » 24 Jan 2018, 21:12

PS_RalphW wrote:The first year is nearly up, and it looks like the turbines have come in about 9% under their P50 annual production at capacity factor of about 27.6 %. (11.4 vs 12.4 GWh)

The standard deviation for annual wind resource at a site is usually quoted as 6% so production is 1 1/2 standard deviations down. Hopefully better next year.

Hang on, you're saying they produced 9% under the P50 projected production? One way of looking at that is to say 2017 was 1.5 standard deviations down, another way would be to say the initial modelling was to optimistic. Can we say which is more likely?

It'll take many years to know site's true P50 capacity factor.

BritDownUnder · Post by **BritDownUnder** » 25 Jan 2018, 12:16

From the DUKES 6.4 spreadsheet information it looks like in 2016 the UK generated LESS energy from wind (20.9 TWh in 2016 compared with 22.89 TWh in 2015) even though the installed onshore wind capacity had INCREASED from 9.2GW in 2015 to 10.9 GW in 2016). It could be that the trend continues into 2017. Basically the UK was less windy in 2016 than it was in 2015. I have read a report somewhere that this is a decadal trend due to global warming but I would guess that your figures are more year on year variability. The Dukes data for 2017 comes out in July.

I did a project at University where I modeled wind power generation in New Zealand using a Rayleigh distribution and compared with data from Weather Underground weather stations. I have lost my statistical knowledge so could not tell you anything about standard deviations of Rayleigh distributions. I do remember the modeled and observed data was close but it could have been luck I guess. Not sure how you would get P50. Probably they put a wind speed measuring tower for a year or so before the turbines went in and based it on that. If it was a windy year then you could have got an over optimistic P50 figure.

There could be other reasons for reduction in national capacity factor. Probably the best wind sites have already been taken.

Post by **kenneal - lagger** » 25 Jan 2018, 16:01

Could it be that wind speeds were too high on occasions which required shutting down of the turbines?

BritDownUnder · Post by **BritDownUnder** » 25 Jan 2018, 18:18

kenneal - lagger wrote:Could it be that wind speeds were too high on occasions which required shutting down of the turbines?

Theoretically possible. However, I think the typical windspeed of a well located windfarm location is 8 metres per second and the shutdown windspeed for a turbine might be 25 metres per second.

Given a wind speed probability distribution such as below...

Those speeds > 25m/s may only be reached 1% of the time.

There are other reasons why windfarms may be shut down. In South Australia some were shutdown on occasions that wind generation exceeded 1200 MW as energy regulators were worried that the grid may become unstable with a low percentage of synchronous generation. I think this has not happened too often. It could also be that the new wind farms are put in places where the grid cannot transmit all their power but I doubt the developers would be so incompetent as to not upgrade the grid first.

vtsnowedin · Post by **vtsnowedin** » 26 Jan 2018, 03:38

BritDownUnder wrote:It could also be that the new wind farms are put in places where the grid cannot transmit all their power but I doubt the developers would be so incompetent as to not upgrade the grid first.

That is a great set of rose colored glasses you have there.
I'm a bit dated but the windmills I have had my hands on would feather the blades so that they would not tear themselves apart in a high wind but would still be producing their max output under that wind. I'll be surprised if the new state of the art mills can't do as well.

woodburner · Post by **woodburner** » 26 Jan 2018, 20:01

Pedant watch.

Theyâ€™re not mills, theyâ€™re genetators.

vtsnowedin · Post by **vtsnowedin** » 27 Jan 2018, 01:07

woodburner wrote:Pedant watch.

Theyâ€™re not mills, theyâ€™re genetators.

What the hell is a genetator?

Post by **kenneal - lagger** » 27 Jan 2018, 14:28

Pedant watch.

Theyâ€™re not mills, theyâ€™re genetators.

Pedant watch

They're not genatators, they're turbines!

woodburner · Post by **woodburner** » 27 Jan 2018, 20:00

vtsnowedin wrote:
woodburner wrote:Pedant watch.

Theyâ€™re not mills, theyâ€™re genetators.
What the hell is a genetator?

Itâ€™s a typo

woodburner · Post by **woodburner** » 27 Jan 2018, 20:03

kenneal - lagger wrote:
Pedant watch.

Theyâ€™re not mills, theyâ€™re genetators.
Pedant watch

They're not genatators, they're turbines!

Turbines? Really? Are you sure they are not propellors driving a gearbox with a generator on the back?

Whatever they are, they are not mills.

BritDownUnder · Post by **BritDownUnder** » 27 Jan 2018, 20:17

vtsnowedin wrote:
BritDownUnder wrote:It could also be that the new wind farms are put in places where the grid cannot transmit all their power but I doubt the developers would be so incompetent as to not upgrade the grid first.
That is a great set of rose colored glasses you have there.
I'm a bit dated but the windmills I have had my hands on would feather the blades so that they would not tear themselves apart in a high wind but would still be producing their max output under that wind. I'll be surprised if the new state of the art mills can't do as well.

Wind power generated by the turbine increases as the cube of wind speed. Most wind turbines generate their rated power around 14 m/s after which the blades become progressively more feathered to maintain this rated power, and as you rightly said so they don't tear themselves apart, until about 25 m/s speed at which point the brake is applied and power output ceases.

Not sure what you are meaning about the rose tinted specs but in Australia there has been a case of a wind farm output being capped below rated due to there not being enough synchronous power generated in the grid.