(GP/GT) for Additional Water Supply in the Lower Rio Grande

In-38
Section UlD - Pro-Forma Economics
for Best Suited Process(es)
Preliminary pro-forma economics comparing the EIm and RQ processes for an assumed 5 mgd plant installation using
mildly to moderately shallow ground waters as feed water sources and purchasing electrical power from the utility grid at
an assumed cost of $.07IKWH, have been prepared previously and were included as a part of Section InA of this Report.
During the period of time between the preparation of the above described pro-forma economics and the present, several
important advances in our level of knowledge have occurred by virtue of our work. These are summarized as follows:
l. We have quantified the projected magnitude of energy, particularly E(G) associated with a single GP/GT
well as being in the range of about 3 megawatts (MW), and have tentatively concluded that this amount
of energy is more than sufficient to power a Smgd desalination plant using either the RO or EDR process,
and including the power requirements associated with the well field, etc.
2. Based on the previous work by R.W. Harden, we have determined that, for the Group 1 waters, there
is a sustainable supply of at least 5 mgd.
3. We have obtained much additional information regarding the quality parameters of the Group 1-4 waters.
By virtue or these advances, we are now able to provide still preliminary, but much more refined, pro-rorma
estimates comparing EDR with RO and, most importantly, quantirying the impact, in terms or potential cor"
savings to the total water cost, which will be derived rrom installation and operation or a GP/GT well al.
appurtenances, as opposed to purchasing electric power rrom the utility grid, as the method or powering the
desalination plant complex.
With this background in mind, the content of this Section In-D consists of the following:
Exhibit IUD-l -
Exhibit InD-2 -
Exhibit IUD-3 -
Exhibit mD-4 -
Exhibit IUD-5 -
Calculation of the projected order~f-magnitude units cost of electrical power produced
from the E(G) component of a GP/GT well drilled into the East Sand or the Bond Sand.
Cost expressed in $IKW Hr.
Assumed input data for pro-forma economic comparisons of EDR versus RO(3)
Pro-forma calculations for EDR using GP/GT power (3)
Pro-forma calculations for RO using GP/GT powerO)
Comparison of purchased power costs versus on-site GP/GT power generation
Note:
(1) Based on a report entitled Kalina Cycle System 12 and Cascade Rankine Cycle for Geothermal Power
Generation - preliminary design and cost comparison prepared for Exergy Inc. by the Calpine Corp.
(2) A copy of this information is enclosed as Appendix H.
(3) Using the same format as utilized previously in Section rnA.