Fuel Types

GPA uses the following fuels:  High Sulfur Fuel Oil (HSFO), Low Sulfur Fuel Oil (LSFO), Number 2 diesel distillate (DIESEL), and Low Sulfur Diesel.

High Sulfur Fuel and Low Sulfur Fuel Oils are residual fuel oils with maximum 2.0% and 1.0% sulfur content by weight, respectively.

Power plants within the Cabras/Piti area must comply with the Cabras/Piti Area Intermittent Control Strategy (CPAICS) as required by the 69.11 (a)(3)(i) of 40 CFR Part 69 Subpart A, as amended, and any modification to the CPAICS approved by USEPA as defined in 69.11(a)(3)(ii).

Under the CPAICS, GPA is allowed to use higher sulfur fuel at its Cabras-Piti facility whenever 15-minute average wind direction and wind speeds are within acceptable limits.  Outside these acceptable limits, GPA must use LSFO.  This arrangement saves ratepayers approximately $3.5 million annually.  Tanguisson Power plant has no restrictions on HSFO use.

GPA uses Low Sulfur Diesel at its Tenjo Vista medium speed diesel plant.  It uses DIESEL at its combustion turbines and medium speed diesel plants.

Historically, DIESEL is much more expensive than HSFO.  In the first week of September 2005, DIESEL prices averaged $76.00 per barrel ($/BBL).  During this period, HSFO averaged $51.00 per barrel.

Currently, DIESEL is still much more expensive than HSFO and LSFO. In April 2007, DIESEL prices averaged $92.00 per barrel ($/BBL). Meanwhile, HSFO averaged only $50.00 per barrel ($/BBL) and LSFO averaged $56.00 per barrel ($/BBL).