Perhaps the greatest challenge for solar energy is its intermittent nature: the sun does not always shine, and of course it does not shine at night. Battery storage is needed to retain the surplus daytime energy so that it is available for use when there is no sunshine. Up until recently, battery technology was not able to do this on a large scale, but a massive new solar plant in the Mojave Desert of California is set to change that. The Edwards Sanborn Solar and Energy Storage Project is located 100 kilometres north of Los Angeles. It incorporates the highest capacity solar farm in the US, with the largest battery storage system in the world. Using the latest high tech batteries will allow the system to produce electricity 24 hours a day. It is expected to provide enough electricity to power the equivalent of 240,000 homes in California. The 1,850 hectare project has nearly two million solar panels, with a total solar capacity of 875 megawatts. The massive battery storage system has over 120,000 high-capacity batteries that can store up to 3,300 megawatt-hours of energy. Connecting so many solar panels to the batteries required 760 km of special wiring.