Too Much Dam Water?

Michael Giberson

Matthew Wald at the New York Times Green blog reports on the Bonneville Power Administration’s problem of having too much water and wind power at the same time.  For about 5 days in early June, storms producing wind and rainwater led to a lot of wind power and too much water in the reservoirs.  As much power as possible was sold to other areas, fossil-fueled generators were cut to essentially zero and even the area nuclear power plants, normally operating at near 100 percent of capacity, were asked to cut back to 22 percent.

4 thoughts on “Too Much Dam Water?

  1. One wonders whether the ultimate consumers paid more or less for their electricity during this period.

    On a previous occasion when BPA had too much water, they brought down the west coast grid twice by overheating transmission lines.

  2. This issue has existed for many years even without wind. The “fish flush” period in May and June became famous in the mid-to-late 90s for low *wholesale* prices in the NW that would be reflected to some extent all the way around the WECC. [Wholesale prices may not have been publicly observable before late 1994, when a few publications began daily reporting of bilateral wholesale prices at COB and PV, and perhaps Mid-C. The distinction of *late* ’94 is important because 94 had been a dry year.] The nuclear unit in the NW would routinely shut down for economic reasons for a month or more in spring. The period from late ’94 through 1999 was a wet period that included some very wet individual years.

    Remember that the CA market was designed and came into being between 94 and early 98. The market opened in March of that year, and one of the early issues was zero prices overnight during May, and perhaps in June (I’d have to check). By 2000, these observed patterns had become expectations, which is why low hydro and widespread heat in May of that year caught the market with so much capacity down for maintenance, beginning the famous crisis. The market had never demonstrated a dry year in its observed history.

    As to whether any ultimate consumers see such low prices, I would guess that some few do, but these are likely large industrials. According to EIA-826, the average industrial rates of some utilities in the NW are very low during fish flush (if they still call it that). In June of 2009 one small transmission-dependent utility with very large industrial sales had an average industrial rate of 2.2 cents/kWh. That’s good if/when you can get it. 😉

  3. Technically you can just disconnect the wind turbines (they do that automatically when wind speeds get too high anyway). I’m guessing the reason that BPA didn’t do that was must-run obligations for renewables. Overall this doesn’t sound like a biggie to me, and if it is a major technical problem then there’s a simple solution of changing the rules about must-run wind.

  4. Well, it is no problem for the nuclear power plant to reduce its efficiency, but it is a much bigger (and more costly) way for coal power plants. Nuclear power plants easily can cope with minute changes in energy consumption, while coal power plans need sometimes hours to cope with big power output swings.

    However, I’d have liked to know whether it wouldn’t be much cheaper to SWITCH OFF wind and water power plants? They could just let the water pass through the turbines without generating electricity…

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