7-2 Air
7-2 Proposed use of Ultra-Low Sulfur Diesel (ULSD) as a Secondary Fuel in the Combustion Turbines
Please clarify when the facility will use ULSD in the combustion turbines as a fuel. Specifically, please identify whether the use ULSD will be a contractual obligation or a choice presented to facility operators on any given day.
The conflicting text includes the use of the word “unavailable” in the RI Energy Facility Siting Board (EFSB) Application, Section 1.2, Page 1: “Each gas turbine will fire natural gas as a primary fuel and ultra-low sulfur diesel (ULSD) fuel as a backup fuel from two-1,000,000 gallon on-site storage tanks for limited periods when natural gas is unavailable.” And in Section 3.1, Page 6: “Each gas turbine will fire natural gas as a primary fuel and ultra-low sulfur diesel (ULSD) fuel as a backup fuel for limited periods when natural gas is unavailable.” Typically, using the word “unavailable” in this situation would mean that natural gas is not available for use as a fuel.
However, the EFSB Application, Section 3.10, Page 18 states: “Additionally, if during the winter season natural gas supplies coming into New England are in short supply or constrained, the gas turbines can be fired by ultra-low sulfur distillate (ULSD), as requested by Independent System Operator New England (ISO-NE).”
Finally, the EFSB Application, Appendix C, Water Balance contains the third drawing in the set submitted, HDR Drawing WMB-04, Rev. C, “Water Mass Balance – 1 CT on GAS, 1 CT on Fuel Oil”. This would appear to indicate that while one combustion turbine uses ULSD as a fuel, the other combustion turbine will still be using natural gas as a fuel. In addition, the drawing set does not include a 4th drawing showing a scenario of both combustion turbines firing ULSD concurrently
RESPONSE 7-2
| Unavailability of natural gas is defined as when there is insufficient gas for the project to meet its capacity obligation and as such could be subject to penalties under Market Rule 1, Section III.13.7 “Performance Payments and Charges in the Forward Capacity Market, otherwise known as “Pay for performance.” Use of ULSD will be a contractual obligation under the “Pay for Performance” construct of the ISO NE Tariff. CREC expects combustion turbine ULSD use will be limited to that needed to maintain oil system readiness and times when natural gas is unavailable. The potential loss of natural gas is expected to be unlikely and if it were to occur would be short lived. Natural gas will be deemed to be unavailable when the natural gas supplier (Spectra) informs Invenergy Thermal Development LLC (“Invenergy”) that the natural gas supply is being curtailed or if there is a Force Majeure event. The availability natural gas is monitored by ISO-NE, who may declare a “Cold Weather Event”, a “Cold Weather Watch”, or a “Cold Weather Warning”, as defined in:
http://www.iso-ne.com/markets-operations/system-forecast-status/current-...
Attached is a Water Mass Balance showing both combustion turbines firing ULSD concurrently. Complete loss of natural gas is not expected, but if it were to occur, this mode of operation will be limited to the capacity of the PUD well (700 GPM) and use of our onsite raw water and demineralized water storage tanks to provide the water injection into the combustion turbines. As mentioned above, we do not expect to operate in this mode as the project expects to have firm gas supply for one of the combustion turbines, (“CT”) so only one CT will run on oil at a time.
|
RESPONDENT:
| John Niland, Invenergy Thermal Development LLC
|
DATE: | May 17, 2016
|