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period. This interruption has reduced deliveries of BPA power 

 to DSI loads at a time when power has been quite valuable. 



It is clear that the DSI reserves, including the first 

 quartile, are of considerable value to BPA (although the value 

 at any particular time may be difficult to calculate with 

 precision) . 



The reserves provided by DSI loads largely reflect the 

 unique capability of the DSI loads to accommodate interruption 

 for various lengths of time with relatively few adverse 

 impacts as compared with interruption of a utility's retail 

 load. 7 



Further, DSI loads do not peak in the wintertime as do 

 Northwest utility loads. The ability to reduce hydroelectric 

 generation (due to minimum streamflow constraints) and thermal 

 generation during periods of relatively low demand is limited; 

 DSI loads help to prevent waste of generation during periods 

 of relatively low demand. 



The benefits that the DSI loads can bring to BPA's 

 operations can and should continue to be reflected in BPA's 

 power sales contracts with DSIs. 



'some DSI loads even have the capability of routinely using more 

 energy during the night (when BPA's other loads are relatively low) than 

 during the day. Such "shaping" of some DSI load into the nighttime hours 

 can reduce BPA's costs, and incentives should be considered to encourage 

 this "shaping" of DSI load. Other modifications of DSI facilities or 

 operations to provide BPA with additional reserves may be available and 

 cost-effective, if reserves are appropriately valued. 



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