Subject: hydropower generation, demand and flow Posted: 9/30/2013 Viewed: 22989 times
Hi
I am wondering why the report "Hydropower Generation" can display results that are much larger than "Hydropower Demand (energy)". For example, in a situation where historical demand is 960 GWh/mo max (and this is shown as "Hydropower Demand"), the "Hydropower Generation" report shows spikes up to 2000 GWh/mo. Plant Factor is set at 95% and efficiency is 95.6%.
In fact, why would "hydropower generation" ever be larger than "hydropower demand (energy)"?
Thanks! Randall
Mr. Jack Sieber
Subject: Re: hydropower generation, demand and flow Posted: 9/30/2013 Viewed: 22981 times
WEAP will generate hydropower for all water released from a hydropower dam, even if it exceeds the hydropower demand. There are several reasons why the reservoir will release more water than is needed to satisfy the hydropower demand, including greater demand for water downstream, or water in the reservoir above the Top of Conservation.
Jack
Mr. Randall Spalding-Fecher
Subject: Re: hydropower generation, demand and flow Posted: 9/30/2013 Viewed: 22976 times
Ah ha! I can see how this could be useful in future scenarios but is there a way to prevent it from happening for a historical time period, where you are trying calibrate hydropower production to actual values? Also, some hydropower plants are meant to be peaking only, so how can you simulate this operation (low plant factor?)?
Thanks! Randall
Mr. Jack Sieber
Subject: Re: hydropower generation, demand and flow Posted: 9/30/2013 Viewed: 22975 times
If your modeled hydropower is much higher than recorded values, either they were operating at a lower plant factor, or your model is overestimating the water released by the reservoir.
Mr. Randall Spalding-Fecher
Subject: Re: hydropower generation, demand and flow Posted: 9/30/2013 Viewed: 22971 times
So one possibility would be to use actual historical production to calculate a load factor and use this as a variable plant factor, yes? Part of this time this reservoir (Cahora Bassa) was not used because the transmission lines were destroyed, so for those years, I will enter plant factor of zero. Does that make sense?
Mr. Jack Sieber
Subject: Re: hydropower generation, demand and flow Posted: 9/30/2013 Viewed: 22967 times
If you are confident that the volume released from the reservoir is modeled accurately and the streamflow below the reservoir matches gauge records, then yes, I think it would be fine to modify the plant load factor to match the hydropower generated.
