Question

Normal Street light have a certain cost and a solar street light also. I need to know the deffrence between and how much it cost in dollar in certain time for example from 6pm until 5am

Answer 1

Commonly used street light in US is sodium-vapour light (rated around 150W on an average). A solar powered LED street light is rated at 60W on an average. Life span of 150W street light is maximum 2 years in best case, whereas LED solar street light life span is between 10-15 years. In order to answer your question we will have to see the operational cost per hour including the purchase price. For the mentioned ratings of respective lights, I see that solar one costs around 40-200 USD whereas sodium-vapour comes around 100-200 USD. Now, considering entire operational lifetime of these lights, the operational cost came out to be 0.03 USD per hour for sodium light whereas 0.002 USD per hour for LED solar light. Considering the time range defined by you (6pm-5am, i.e. 11 hours) normal street light would cost around 0.33 USD whereas solar light would cost around 0.022 USD. So within that time range you would have a profit of 0.308USD by using solar light. However, keep in mind that sodium lamp requires more maintenance cost and would have to be replaced after 2 years. So if we evaluate the cost benefit for two years, the profit in using solar light would be around 20 USD.