Question:
> . . . >There were a couple of processes that were known to work. They were >not economical, but were not THAT far from economical … and could >be pressed into service in an emergency… The same technology could >be used with any electrical or very hot thermal source. This is >why better storage is bad for solar and wind … it puts them in >competition with nuclear BASELOAD costs, modulo the storage cost…
I guess I don’t quite follow your line of reasoning. The data I posted suggests that most of the seasonal variation in load is due to electric space heating. Short-term storage for this ( storage furnaces, etc.) is a fairly well understood technology and neither exotic nor terribly expensive. Dual-fuel heating systems can also be used to pick up the slack in low-wind conditions. These technologies might benefit wind mills because the numbers seem to show that wind energy is generally available when there is a space heating demand. They might not benefit nuclear directly because of the much larger supply-demand mismatch, increasing the cost of storage. Of course, as I said before, they might benefit the nuclear industry indirectly. A utility that builds a CGT peaking plant or fossil- fired steam plant to meet intermediate loads has the option of just increasing the duty of these plants, rather than constructing new base-load power plants, when base-load grows. Such options, while not economically optimal, may be financially preferable for a cash-strapped utility facing a major battle to site a new base-load plant. If wind mills and appropriate storage turn out to be economic for meeting seasonal peak and intermediate loads, and they are deployed in significant numbers, then two factors seem significant: 1. lower costs from using an optimal technology can improve the financial situation of the utility, preparing them for construction of a capital-intensive base-load plant, and 2. the option of simply running peak- and intermediate- load plants at (uneconomically and environmentally-damaging) high capacity factors has been foreclosed, because the capacity factor is set by the availability of the wind resource. These two factors suggest that, rather than fighting ideologically-driven, rear-guard actions against every new idea that doesn’t involve neutrons, the nuclear industry and those who support it should spend some time thinking about markets as a whole and developing consensus. Incidentally, our utility put forward the following cost estimates for new capacity (delivered in 1995) a few years back. I’ll leave it to others determine where wind power fits, since I don’t know the expected life of the system. The interest rate used was 11.5%, I think. Capacity Factor 5% 25% 80% 1. Generic nuclear $770 $780 $800 per KW-yr 2. Generic coal $360 $430 $660 " " 3. CGT $150 $400 $1120 " " 4. Combined-cycle $230 $370 $760 " " Ken
Response:
I looked up the average monthly wind speeds for my location, just for the fun of it. It does indeed seem to blow faster in the winter. Noting that power is proportional to speed cubed, and normalizing the results, I get the following wind "power" data. I’ve also included our utility’s peak and average power demand, just for comparison purposes. Month Fraction Electricity Demand 1990-1991 Wind Energy Peak Average MW MW Jan 0.111 2637 1925 Feb 0.105 2573 1985 Mar 0.118 2438 1761 Apr 0.089 2005 1500 May 0.078 1840 1306 Jun 0.066 1676 1267 Jul 0.047 1504 1130 Aug 0.043 1548 1175 Sep 0.056 1679 1238 Oct 0.078 1911 1407 Nov 0.099 2085 1564 Dec 0.110 2407 1833 Annual 1.000 2637 1508 The monthly variation in demand is dominantly influenced by air temperature. This means that high winter demands can occur in calm wind conditions, and wind power alone cannot meet all (or even most) of the seasonal load variation. Space heating loads are known to increase with wind speed, however, and it is quite possible that the system would benefit from some small amount of wind power (100 MW or so?). Short term energy storage for wind produced energy would also seem to be worth investigating. Please also note that nuclear plants, which need capacity factors in the region of 80% to be economic, also cannot meet the seasonal demand variation. The load is met by fossil-fuelled plants, dominantly oil, and some small amount of seasonal hydro- electric capacity. Long term energy storage for nuclear source energy may also be worth investigating, but my guess is that such storage would be even more expensive that the short term storage for wind energy. Ken
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