Solar panels could be used to produce electricity, then store it in batteries in order to use it for lighting whether street lighting or garden lighting. The main idea is converting usage from normal electricity to a renewable one that serve the same subject of use.
This reduces the pollution extracted environmentally, also return an advantage as a kind of investment. As some governments accepts to buy electricity produced from civils in order to encourage use renewable energy sources instead of ones depend over oil and petrol. Also the producer himself has the advantage of getting his investment refunded within 7 or 8 years in average, just from saving bills payments.
Normally systems goes in continuous work for 20 years or more. Thus all extra years are considered as profit. In solar lighting systems in general refund period could be with 8 years or less. While in our professional solar lighting systems, our R&D makes achievements to produce higher quality and lower cost solar products. Which means also to make refunding period more and more less.