Four main cases were added to the test system, each providing an approximately equal amount of energy.
1. A flat block of zero-cost energy. This provides a point of comparison to examine how the temporal characteristics of solar energy compare to a constant or “baseload” resource. To provide an equal amount of energy, the capacity of this block was set to 123 MW.
2. Solar PV. Discrete-sized 1-axis tracking PV plants generated for the WWSIS project were added in each case until the generation equaled about 1,070 GWh, with a total installed capacity of about 580 MW. The total operating reserve requirement was also increased due to the additional short-term variability.
3. CSP no storage. A single 568-MW plant with a solar multiple of1.3 was added to the San Luis Valley in southern Colorado. This plant produced 1,130 GWh.
4. CSP with 6 hours of storage. This case adds a 300-MW CSP plant with a solar multiple of 2.0, as discussed previously. The actual amount of energy delivered to the system varied slightly in each scenario based on the amount of energy stored (due to storage losses).
Each of the cases was simulated in both the low and high RE scenarios.
Several sensitivity scenarios were considered, as discussed in Section 5.4.