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<br />. <br /> <br />FIGURE (3) shows a typical weel{l.v load curve showi.np; the naily peaks and <br /> <br />vallevs and a typical baseload generation pattern superimposed on the load <br /> <br />curve. The haseload is greater than the minimum demand (valleys) >'ut not <br /> <br />as great as the maximum demand (peaks). Peak demands are met from other <br /> <br />sources. such as peaking ?ower plants. or facilities that are operated <br /> <br />only during those perio~s of time. In this way, the haseload plant runs <br /> <br />at high efficiency, and the peaking plant runs when needed to meet demand <br /> <br />at peak times. <br /> <br />FUT:'tl,er breakdown5 into l>ase. intermediate, anc1 peaking <br /> <br />loads can furt~er increase the efficiency of t~e overall system. <br /> <br />Peaking power can be produced in several ways. Often oloer. l.ow <br /> <br />effici.ency coal-fired steam plants are used. T~p.:se plants consume a ~l"eat <br /> <br />nea1 of energy ann are sl.ow ~n startnp, l,ut t~ev also save t~e large <br /> <br />capital <br /> <br />costs .of new plant construction. A second popular solution ~s <br /> <br />oil-fired comhustion turryines. <br /> <br />These turhines ~ave t~e anvantages of <br /> <br />. <br /> <br />fai.rly l-tigh efficiency.and quick startup, but oil. is becomin~ scarce and <br /> <br />is becoming more expensive. T~e third common peakin~ source is ~vdroelec- <br /> <br />trTc pO{oTer. "Hydro peaklng." as ~t is called. can rye supplip.rl either by <br /> <br />conventional hvdro or >,y pumpe~ storage. Either methon is well. suited for <br /> <br />pea~ing operations. <br /> <br />FIGURE (4) <br /> <br />shows a conventional ~ynro which u~es a <br /> <br />;. <br /> <br />typical dam-reservoir system wit~ releases made rlurin~ peak periods. <br /> <br />T'hese pl ants t,ave tlte advantage of consumj.nli; no fuel and ~ave an inunediate <br /> <br />startup capability. Carrie~ to tl,P. extreme, however, tl1e river below tl,e <br /> <br />channel. would be dry or nearly dry part of each day. T'tis is impractical <br /> <br />because of (1) the requirements of downstream water users. (2) the need to <br /> <br />preserve l-tahitat for aquatic 1i.fe. or (3) the need for r,ver water for <br /> <br />recreation boaters. <br /> <br />. <br /> <br />01"2 <br /> <br />5 <br />