Technology

## Additional Tools to Estimate Maximum Power

Matt Deady, Professor of Physics, Director of the Physics Program, Bard College

The power calculator and mapping tools are just two ways of calculating maximum power. There are other tools that you can use to estimate maximum power, and to look at how changing the head or flow will affect the potential power output of a site.

The formula presented in Calculate Maximum Power is fairly straightforward, but there are other ways ways to look up and double check your power calculation. The table allows you to find the power by cross-referencing the flow rate (columns) with the head (rows). For instance, (h=3m , Q = 1.2m³/s) gives P = 35.3 kW, as expected, just a bit bigger than the calculated value using (h=2.7m , Q = 1.2m³/s); and (h=18m , Q = 1.2m³/s) gives P = 212 kW, as calculated. This table can also help to quickly see the difference in power output by changing the head and flow.

#### Table: Maximum Hydro Power (in kW) for Head and Flow

Flow (m³/s)0.511.522.533.544.55
15101520252934394449
210202939495969788898
3152944597488103118132147
42039597893118137157176196
525497498123147172196221245
6295988118147176206235265294
73469103137172206240274309343
83978118157196235274314353392
94488132176221265309353397441
104998147196245294343392441490
1154108162216270323377431485539
1259118176235294353412470529588
1364127191255319382446510573637
1469137206274343412480549617686
1574147221294368441515588662735
1678157235314392470549627706784
1783167250333417500583666750833
1888176265353441529617706794882
1993186279372466559652745838931
2098196294392490588686784882980
211032063094125156177208239261029
221082163234315396477558629701078
2311322533845156467678990210141127
2411823535347058870682394110581176
2512324536849061373585898011031225
26127255382510637764892101911471274
27132265397529662794926105811911323
28137274412549686823960109812351372
29142284426568711853995113712791372
301472944415887358821029117613231470
311523044566087609111063121513671519
321573144706277849411098125414111568
331623234856478099701132129414551617
3416733350066683310001166133314991666
3517234351568685810291201137215441715
3617635352970688210581235141115881764
3718136354472590710881269145016321813
3818637255974593111171303149016761862
3919138257376495611471338152917201911
4019639258878498011761372156817641960

Or, you can use the graph to estimate the power by looking up the flow rate (x-axis) and head (y-axis). Lines of various values of power are plotted for reference, and can help to illustrate the head vs. flow trade-offs.

Note: This is a logarithmic graph, with the axis hash marks corresponding to values:

{ 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50 } Figure: Maximum Hydro Power (in kW) for Head and Flow

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