Kapolei, Hawaii, USA The Honolulu facility is a 3,000-tonne-per-day energy system consisting of a 2,100 tpd refuse-derived fuel plant built in 1990 and a 900 tpd mass burn plant added in 2012. The system is owned by Honolulu and operated by Covanta. H-POWER landfills about 150,000 tonnes of ash per year. The city awarded Covanta a project, which is in the early stages, that involves extracting clean aggregate from the ash and reducing between 60 and 80 per cent of the landfilled ash. The success of this venture could potentially boost the city's already high 82 per cent landfill diversion rate to more than 90 per cent, which would rank it among the top cities in the country.