Solar powered mobile phones are able to charge using sunlight by integrating solar cells and panels. The first solar phone was invented in 2007 and had solar panels that trickle charged the battery, extending its life by 2.5 times. Solar mobile phones provide a sustainable option as they can charge in any light condition without needing electricity, making them particularly useful in rural areas. New technologies are exploring transparent, flexible solar screens built into displays to charge phones without needing separate panels.