Reply #40: Wind Power Math [View All]

[arachadillo]

Thanks all for the responses, let's see if I can make some types of general, summary sense....

Most experts adopt an electricity maximization approach when trying to incorporate large scale wind electricity generation into long term total electricity generation scenarios. The problem, however, is that wind energy generation is highly variable and not suitable to storage (as might be the case with solar and molten salt storage).

The issue with wind power in the UK might be high variability in average wind speeds, or insufficient data (three years of partial wind energy production), or a combination of both factors.

XemaSab says: The problem with "planning" for 25% is that you actually have to plan for 0% *AND* 50% at the same time.

Coal and nuclear plants cannot be turned on and off easily depending on whether a particular day is windy or still, so natural gas and hydro must be used to make up for the still days when there is no wind. This means that for every wind farm, you have to build another peaker facility somewhere to make up that energy when there's no wind feeding into the grid.

That makes sense to me...

txlibdem says: These show that Scotland has far and away the best winds in the UK. Also mentioned earlier is the fact that the UK has about 1GW in wind power and has 2.7GW in pumped hydro storage with a 5 hour store, about 1.6GW of that can last another 17 hours, for a total of 22 hours of storage. This is an excellent model for the US although I'd like to see an 8 hour store for peak energy times and a "base" storage of 24 hours.

At issue is finding a 24 hr "base" storage medium. Far as I can tell, only the Pacific NW has sufficient hydro to even attempt to reach that goal. What can TX do for storage when its wind farms are taking a time out?

as an aside, sorry about the quoting out of context, I do not refute Uk wind energy potential numbers, I'm just suggesting that I do lean to thinking of onshore wind potential as highly variable. Maybe three years of statistics is insufficient for use in that study. Maybe three years from now, the numbers would look a bit different, (i.e., longer term data helps smooth out bumps in short term statistical analysis...after all, NOAA keeps average wind speed caclulations for major cities based on long term statistics
http://www1.ncdc.noaa.gov/pub/data/ccd-data/CCD-2009.pdf (put page 66 in the search to retrieve the long term average wind speeds)

also, I just returned from a trip to your wonderful state. Boy is it windy in March along the LRGV:)

PamW says, One of the problems with wind power is a result of plain basic physics. That is that
the power of a wind turbine goes as the cube of the wind speed.

If the wind turbine sees wind that is 50% of its maximum rated wind velocity, then it should produce 50% of the power that it would at that velocity. Right? WRONG!

It will produce 1/8-th the power. If your wind turbine is rated at 800 kilowatts in a maximum 50 mph wind, then at a 25 mph wind, it will produce 100 kilowatts, not 400 kw.

I've been trying to read many of the technical specifications from manufacturers regarding average annual wind speeds and electricity generation potential. The curved graphs they present for their electricity generation potentials verify your presentation.