The Natural Energy Laboratory of Hawaii Authority (NELHA) administers the Hawaii Ocean Science and Technology Park (HOST Park). NELHA was founded in 1974. At 870 acres (350 ha), HOST Park is perhaps the largest single green economic development project in the world solely devoted to growing a green economy. NELHA also administers a small site, 4 acres (1.6 ha), in Puna on the eastern side of the Island of Hawaii for geothermal research. The original mission was for research into the uses of Deep Ocean Water in Ocean thermal energy conversion (OTEC) renewable energy production and in aquaculture. It later added research into sustainable uses of natural energy sources such as solar energy. Its administration offices are located in the HOST Park Keahole Point in the North Kona District. The entrance is on the Hawaii Belt Road at coordinates (19°42′58″N156°02′01″W), just south of the Kona International Airport.