Renewable Energy Technology Assessments - Kauai Island Utility ...

Kaua’i Island Utility Cooperative
Renewable Energy Technology Assessments
3.0 Renewable Energy Technology
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fuel production. While recycled fats and oils are the most difficult feedstock to process
because of their variable content, they are generally inexpensive.
The fat and oil resource is likely too small to consider for power production.
Dedicated crops would need to be planted for large scale production. While not currently
grown on the island in any significant quantity, oil palm is considered to be one of the
best sources of vegetable oil for biodiesel production and could easily be grown as it is
well suited for tropical climates. The reported yield of biodiesel from oil palm is 635
gallons per acre annually, which is over 30 times the yield from corn and 13 times the
yield from soybeans. 23 One local businessman expects yields to be even higher, around
1,000 gallons per acre per year. 24 If grown on twenty percent (28,000 acres) of Kauai’s
zoned agricultural lands, about 17.8 million gallons of biodiesel per year could be
produced. In comparison, Kauai consumed 2.2 million gallons of diesel for
transportation in 2003. 25 Kauai could easily supply a substantial portion of its diesel fuel
needs and have a large amount remaining for power production. Assuming power
generation from the entire biodiesel supply at a heat rate of 9,000 Btu/kWh (HHV),
approximately 240 GWh/yr of electricity could be produced from a 34 MW baseload
power plant.
Compared to ethanol, biodiesel can be integrated more easily into KIUC’s
existing diesel oil fuel supply and power generation infrastructure. Starting with perhaps
a 2 percent biodiesel blend, KIUC could gradually increase the percent of biodiesel
supplied to its power plants without noticing significant equipment impacts.
Alternatively, KIUC could incrementally add B20 capability to selected units until the
entire thermal fleet was fueled with a biodiesel blend. This would allow the utility to
quantify and monitor biodiesel impacts on plant performance, emissions, and longevity
prior to widespread implementation. Regardless, in the near term, biodiesel potential is
constrained by the supply of the fuel. It is estimated that only 25 million gallons were
sold in the United States in 2003. 26 Large scale biodiesel production on Kauai with oil
palm would require significant investment in a new plantation and production facility, an
activity that probably could not be expected to be mature for ten years. In the near term,
KIUC could meet its needs from smaller producers and imports from other islands. Table
3-10 outlines a potential development scenario for biodiesel power production on Kauai.
23 Joshua Tickell, From the Fryer to the Fuel Tank, 2000.
24 Bill Cowern (Kauai Mahagony), personal communication, June 15, 2004.
25 State of Hawaii Department of Taxation, “Liquid Fuel Tax Base & Tax Collections”, 2003.
26 National Biodiesel Board, “Frequently Asked Questions”, available at:
http://www.biodiesel.org/resources/faqs/, accessed August 2004.
21 March 2005 3-31 Black & Veatch