Handbook of Energy Storage for Transmission or ... - W2agz.com

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4.2.1 Application 1: 10MW Load Leveling (200 NAS PS Modules)
The base-case load-leveling application assumes that value elements consist of:
cost/benefit analysis
• Avoided T&D system upgrade valued at $1000/kW, e.g., any combination of right-ofway,
transformers, conductors, peak generation
• Energy price and demand charge reduction per Table 4-3.
For this application, a system designed for simple peak shaving the equivalent of 8 months per
year (~167 cycles) with no other functions yields a NPV of $4.6M. However, if the same system
is equipped with PCS suitable for grid interactions, it can also provide AGC 16 hours per day
during the equivalent 4 months per year when it is not assigned to peak shaving duty. Assuming
an incremental increase in PCS/BOP of cost from $250 to $300/kW for the grid-interactive
capability, the NPV of this combined function application is assessed to be $8.4M. Costs and
benefits for these options are summarized as follows:
Table 4-4. Cost/Benefit of Load-Leveling Applications
Base Case
Alternate
Load Leveling (LL) LL & AGC
Initial Installed Cost, M$ 17.7 18.2
Total Costs, M$ (Note 1) 31.0 32.1
Total Benefits, M$ (Note 2) 35.6 40.6
NPV, M$ (Note 3) 4.6 8.4
Notes:
(1) Total Costs: Present value of initial capital, operating, replacement,
taxes and insurance costs
(2) Total Benefits: Present value of avoided costs and revenues
(3) NPV: Total Benefits minus Total Costs
4.2.2 Application 2: 10MW Power Quality (40 NAS PQ Modules)
The base-case power quality application assumes that the system is valued at the avoided cost of
a commercial system of functional parity. Specifically, it is assumed that a static DSTATCOM
PCS with four-quadrant control and NAS energy storage is functionally equivalent to a bank of
Piller Triblock rotary systems which can provide grid interactive sag protection plus frequency
and VAR support. The value of the Triblock is estimated at $1000/kW based on initial
(commercially quoted) price plus capitalized values for operating, maintenance, taxes and
insurance costs. For the base-case application, the NAS system is configured to deliver 5 times
rated power (250 kW per module) for up to 30 seconds.
On this basis, NPV of the NAS system for the base case application is slightly positive ($100K),
indicating the lifecycle costs for the two systems are essentially equal. However, if power quality
functions are combined with load leveling, as indicated in the Alternate case in Table 3-3, the
NPV increases to $1.4M. The duty cycle provided by the NAS system consists of the 30-second
pulses to mitigate power disturbances at any time, plus 3 hours load leveling, 5 days per week.
Adding load leveling requires that the number of modules be increased from 40 to 47 and that
4-3