By Bill Palmer
For those interested in technical details, I ran across an interesting source of data (new to me) today from the Texas “ERCOT” site. Others may or may not already be aware of this site, so I apologize if this is simply old news. For those not into the technical details, I attach a few pictures that help to explain the problem.
ERCOT are the system operator for wind in Texas. A bigger grid than Ontario, with typical summer peaks of 65,000 MW (vs 25,000 MW in Ontario), Texas currently has just under 10,000 MW of wind. The ERCOT site provides lots of nice wind integration charts like these at:
http://www.ercot.com/gridinfo/generation/windintegration/ as well as wind performance vs prediction.
They have articles proudly announcing that in July 2011, wind output reached a peak of some 7400 MW (about 78% of their system wind capability then) … not as good a performance as Ontario’s wind, for which our IESO or Sygration Sites often show the monitored Ontario wind farms at over 95% of output durng windy days as we have seen within the last month.
The interesting data of course is the reciprocal … when the nearly 10,000 MW of wind turbines on ERCOT provided perhaps 500 MW during system peaks in August 2011 … see the attachment for August 24. Wind was providing 4228 MW (about 44% of wind capability supplying over 10% of the system needs) when the system demand was 40,000 MW at 1 AM … but then wind dropped to near zero as the system demand rose to 60,000 MW, and wind recovered only to 970 MW (about 10% of wind capability supplying 1.5% of the system needs) during the system peak of 66,552 MW during the 17th hour of the day. It is much like when the 1400 MW of Ontario Turbines supplied less than 5 MW during our system peaks of 24,000 MW at times in August 2011. The problem in Texas, in Germany, in Britain, and here in Ontario, is that the wind performance often peaks when the system demand is low, and drops to near nothing when the demand is high. Ontario compenates today with 1400 MW of wind generation by backing down the Bruce Nuclear Reactors at night and firing up gas gnerators in the day … see the dips in the Sygration charts for Bruce Nuclear Reactor Output attached – one curve from Summer Daa and one from winter data as examples … when they were derated while system generation was too high … otherwise known as wind at high outputs when system demand was low.
Without getting into the technical details, I will state my personal opinion (based on 30 years of operating experience at the Bruce site) this is one heck of a way of running a nuclear unit that is really intended for baseload operation … the official position will be that it can be done, but I stand on my personal statement.
Anyhow, really my intent was to flag folks to the ERCOT site … today I note that the forecast from yesterday afternoon showed the system wind capability would be 6500 MW this morning … turns out it is actually 4500 MW, so the system operator is scrambling to find 2000 MW of generation on short order … no small challenge when it happens day after day. Tomorrow the prediction is for the system wind capability in Texas to be about 1500 MW …
It is intrieguing to think of the effect on the 25,000 MW Ontario system when it acheives the planned 8,000 MW of wind capability by 2018 predicted on the IESO 2012 calendar. (actually it says 10,700 MW of renewable from wind, solar, and bioenergy by 2018, but most of this is wind). Actually, it is not intrieguing … it is a nightmare. The system operation will be very difficult, and expensive. Nuclear will not fit as there would be too much baseload generation at night, and then in the daytime, the natural gas generators would be fully loaded. Costs will be perhaps 3 or 4 times what they are today … until gas prices start to increase due to the demand … and the fact that the Chinese investors in the new fracking operations producing the natural gas output start turning the screws on the price. We are headed towards great trouble economically – the curves show it clearly.