The two remaining projects are for cogeneration and biogas recovery and electricity generation. Hawaiian Electric Industries also burns bagasse for cogeneration. This segment also owns a 51 megawatt cogeneration power plant. They mostly use coal and gas-powered steam turbines for cogeneration of heat. COGEN is Europe's umbrella organization representing the interests of the cogeneration industry. The cogeneration of electric energy and district heat also improves efficiency. The bonuses for solar generated electricity and cogeneration are cumulative. Such cogeneration systems can yield theoretical efficiencies above 95%. Today its natural gas cogeneration plant has a capacity of 123 MW. It is possible to use waste heat in cogeneration applications such as district heating. The treatment plant and cogeneration facility were formerly operationally separate. The European Union generates 11% of its electricity using cogeneration. In most Eastern European countries, energy planning included development of cogeneration and district heating. In the sugarcane industry, the organic waste is usually burned in the power cogeneration process. Cogeneration plants face possible contamination of returned condensate.