A User's Manual for DELSOL3 - prod.sandia.gov - Sandia National ...
A User's Manual for DELSOL3 - prod.sandia.gov - Sandia National ...
A User's Manual for DELSOL3 - prod.sandia.gov - Sandia National ...
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nSTOR is determined from an assumed maximum volume per tank:<br />
VSTOR<br />
nSTOR =<br />
VTK,MAX<br />
where V~TOR = total volume required <strong>for</strong> storage (m3)<br />
VTK,MAX = maximum tank volume (m3)<br />
For non-integer values, nSTOR is rounded to the next highest integer. The total<br />
storage volume is related directly to the energy in storage:<br />
VSTOR = VTK,REF<br />
ESTOR,REF<br />
where E~TOR is the energy in storage. The individual tank<br />
volume is:<br />
(V.A - 16)<br />
(V.A - 17)<br />
assuming that multiple tanks will be constructed of equal volume. If only a single<br />
tank design is desired, the user can choose an appropriately large value <strong>for</strong><br />
VTK,MAX-<br />
In DELSOL, storage is initially sized <strong>for</strong> the excess energy <strong>prod</strong>uction on the<br />
longest day, June 21st. This storage size is always calculated and used in the system<br />
optimization process. The calculation of E~TOR is illustrated in Figure V-3.<br />
Its value is determined by a numerical integration to give the shaded area in the<br />
figure. The nominal number of hours of storage is simply E~TOR divided by PDES.<br />
The assumption is made that this day will require the largest storage tank, so<br />
that no energy is thrown away at any time during the year. However, <strong>for</strong> north<br />
biased fields this assumption is not necessarily valid, since due to higher field efficiencies<br />
at other days of the year the integrated value mentioned above could be<br />
higher at another day than June 21, thus leading to discarded energy when the<br />
storage tank is sized <strong>for</strong> June 21. On the other hand, it is possible that having a<br />
smaller storage tank and discarding energy may be more cost effective than never<br />
discarding energy. The user is there<strong>for</strong>e given the option of optimizing the storage<br />
size to balance the cost of the storage tank against the cost of discarding energy.<br />
This option, which is specified using the variables ISTR and NSTR (Section<br />
1V.C-S), is requested as part of system optimization, but the storage optimization<br />
and final storage tank cost calculation is done during a final per<strong>for</strong>mance calculation.<br />
This is the only component cost which may be recalculated during a final<br />
per<strong>for</strong>mance calculation.<br />
Default values <strong>for</strong> calculating storage costs are based on a hot tank/cold tank<br />
design:<br />
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