Solar powered Trash Compactors compresses waste and increases the capacity of the trash cans/dustbins. Trash compactors are a very efficient way of collecting/storing waste, when compared to the normal/static dustbins we currently have. Growing trash/waste is a huge concern for any city, and most often we witness accumulated waste all around the dustbin or waste spilling out from the dustbin as they are filled to their capacity.
Basically, compactors compress the waste materials to create more space in the dustbins. They apply pressure to do so and the energy required for this process is obtained from directly attached solar panels and batteries. Batteries ensure that even if there is no sun for 2-3 days (for example), the compactors would still work. There are sensors that determine when to undertake the process of compressing the waste and it is undertaken automatically, without any human intervention.
Generally, compactors can store five to six times the quantity of waste, when compared to a normal dustbin. This reduces the number of trips required for the collection trucks, and hence saves a lot of diesel/fuel.
Some compactor units can be fitted with smart communications modules that communicate with a central server over the cellular network to inform the authorities on when it is time to empty the dustbins. This facility makes sure that collection trucks visit the most appropriate dustbins only and they are on-time. Based on real-time data, garbage collection can be planned in a very efficient way that saves a lot of money, otherwise spent on fuel. It also allows authorities to easily monitor all dustbins in a city, from a central location.
Limitations of such a system include higher cost per dustbin (that can be easily repaid due to the lower operating cost and efficient waste management system) and outdoor-only installations (as the solar panels need exposure to direct sunlight). But then, the cost is just a one time expense as solar panels work reliably for 20-25 years without any maintenance. Batteries might need to be replaced after a point of time, though.
So, why don't we switch over from normal/static dustbins to solar-powered compactors? There is at least one company that manufactures such systems.