416 



FITTINS i^ 



M ULAAM. 



The sun doesn't generate at night. So what about 

 storage? The HYDRO and SOLAR generation combination 

 is a unique opportunity in the Pacific NorthHest. The 

 diurnal and seasonal variation of the solar 

 photovoltaic resource can be balanced against water- 

 budgets, pond-storage, pumped-storage, morning/evening 

 fish-migration spills, and firming the nonfirm 



hydropower. Nonfirm energy that over and beyond 



the historic dependable flow of the river when 



available is prioritized first to the interruptible 

 Direct Service Industries, second to displace Northwest 

 thermal plants, and the remaining sold to Southwestern 

 utilities. In the BPA system, the diurnal and seasonal 

 variation in Solar-Fuel generation can be dispatched to 

 firm a portion of the non-firm hydropower; here illus- 

 trated for one probability of availability of non-firm 

 energy. Using solar-fuel weather models probabilities 

 of availability can be determined Just as hydrographic 

 projections are now made for river-flow 'hydro-fuel' 

 and non-firm energy at BPAs Dlttmer Control Center. 



MONTHLY FIRMING THE NON-FIRM HYDROPOHER ENERGY - aHH 

 (SOX Probability of Hydro Availability compared to 



the m.S Plants, 41,500 HH of SVG capacity) 



Page 8 



