Biomass was attempted, using keawe for fuel.  Harvesting from the mountainside proved challenging, but it worked and keawe burned hot! Though farming trees for this purpose would have been less costly and more practical in the long run,  landowners disagreed.  I thought keawe is better than burning coal...which I didn't know they used in Hawaii.  Since we have no coal to mine in Hawaii, must have been mega bucks to ship it here.