December wind generation

[Devil]

Before anyone gets on at me by saying that I do not live in Paphos, what I am about to say applies to the whole country.

It is not sufficient that the wind turbines are turning. They do not generate any electricity at wind speeds of less than 4 m/s. Depending on the design, they require a sustained wind speed of 12 to 15 m/s, to obtain their full output. Gusting generally reduces the output by anything from 30 to 80%.

During the month of December, at my location, the highest sustained wind speed was on the 11th at 1.0 m/s and the highest gust was 11.8 m/s on the 14th but the average on the same day was 0.5 m/s. My location is fairly sheltered, so that the wind in winter averages about one quarter of the official wind speeds, so that you can safely multiply these figures (except the 11.8 m/s) by between 3 and 4 to obtain the average, countrywide.

In other words, December was pretty catastrophic for electricity generation in our windfarms.

Another measure which gives an idea of what is going on is the wind run. Put simply, this is the distance a tiny light feather would fly. Again, in my location, multiply the figures by three to four. In effect, the wind run approximates an unknown proportion of the electricity that would be generated. Over the month so far, the lowest wind run was a mere 1 km on the 19th December – you could puff that! The highest wind run was on the 11th, which correlates with the earlier paragraph and was only 86.1 km, which is still very low. The average for the month was about 10 km per day.

[jeba]

Perhaps invested for the wrong reasons. The only 'clean' guaranteed 24 hours a day electricity delivery service (I can think of) is tidal and nuclear. Everything else is subject to the vagaries of the weather. Wherever you live.

You forgot geothermal.

[Devil]

Perhaps invested for the wrong reasons. The only 'clean' guaranteed 24 hours a day electricity delivery service (I can think of) is tidal and nuclear. Everything else is subject to the vagaries of the weather. Wherever you live.

Tidal is clean but very variable (spring and neap) with individual power units going 'out' twice a day. Also requires oceanic water (NBU for Cyprus). Nuke goes out for long maintenance periods.

[Aargent]

I have often wondered why, not in Cyprus obviously, there isn’t more use of the big rivers, for instance, if every bridge over the Thames or the Severn had a generating turbine or two attached the same water would work time and time again and it would be 24hrs a day every day of the year . These big rivers never stop. Somewhere in my mind the French do it in Paris on the Seine.

[Devil]

The simple answer is silt. To turn a turbine, you need energy provided by the water flow. The latter is slowed down, so that the sediment drops, in time blocking the water output.

As far as the Thames is concerned, I think the last restriction is somewhere near Kew in the form of a weir. The only way round the problem would be to have dams across the Thames with a height of, say, 50 m. I do not think the landowners would be happy to have their property turned into a lake.

If I may be allowed to make a joke, your idea is weir-d.

[Princebytor]

Surely the 'brussel sprout' affect over Christmas will push the stats up towards the end of the month................

[Devil]

Surely the 'brussel sprout' affect over Christmas will push the stats up towards the end of the month................

I have never had this effect and I love Brussels sprouts.