Hawaiian Electric Co. used 100 percent renewable biofuel to fire a 90 MW petroleum oil-fired steam turbine generator.

The test showed that emissions of closely regulated and monitored gases and substances were
less than emissions from corresponding operations with fossil fuel. Using biofuel reduced opacity (visibility of emissions) and emissions of nitrogen oxides (NO_X) and sulfur dioxide (SO₂) compared to using low sulfur fuel oil.

A company release said this may be the first time a utility-scale steam unit has fired on 100 percent biofuel at
100 percent capacity.

The Kahe #3 Biofuel co-firing demonstration Project is being conducted in cooperation with the Electric Power Research Institute to determine how much biofuel can be used to offset the use of fossil fuel oil in steam generating units.

Hawaiian Electric began firing unit #3 at 38 MW and then adjusted the fuel blend to 100 percent biofuel and took temperature and emissions readings. The unit was then stepped up to 60 MW, then to 88 MW and finally to 90, in each case followed by testing. Tests earlier in January had used various blends of biofuel and low sulfur fuel oil.

Testing will continue and be expanded to evaluate continuous 24-hour operation on Hawaiian Electric’s energy management system. Results will assess the possible use of sustainable biofuels in Hawaiian Electric, Maui Electric and Hawaii Electric Light companies’ other steam generating units.

In June 2010, the Hawaii Public Utilities Commission approved Hawaiian Electric’s biofuel test plan. In addition, the PUC approved a contract for Sime Darby, a Malaysian multi-national corporation, to supply 1.6 million gallons of biofuel for the test.

The test uses crude palm oil blended with palm stearin, an inedible by-product of palm oil refining usually used to make candles and soap. 

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