Its remoteness and the measures needed to protect its population from the harsh environment give it an insular character. The station is not self-sufficient – the U.S. military delivers 30,000 cubic metres (800,000 US gal) of fuel and 5 kilotonnes (11 million pounds) of supplies and equipment yearly through its Operation Deep Freeze resupply effort[7] – but it is isolated from conventional support networks. The base generates electricity with its own power plant, and grows fruits and vegetables in a hydroponic green house when resupply is non-existent.