There are quite a few promising lines of research in alternative energy. One of them is obtaining electricity from rubbish.
Processing waste to create energy reduces landfill content as well as reliance on fossil fuels. In fact some first world countries are even exporting garbage to third world locations. Most waste to energy plants process waste biomass such as food or garden waste. They may do this by burning the waste and capturing the heat, but there are now more sophisticated methods. For example, it is possible to ferment organic waste to produce ethanol which is then used to fuel cars. Or it can be processed to make methane which can be used directly as fuel for heating or cooking or to power gas turbines to create electricity.
On the edge of viability is breaking down plastic to create synthetic crude oil which could be used either as fuel or to make more plastic. Thermal gasification is also becoming common. The amount of waste being processed to create energy is dramatically increasing and some countries consider it to be renewable energy. At the very least, it is better than leaving stuff to rot in landfills, creating thousands of cubic feet of methane per ton of waste, that then does nothing but leach into the atmosphere and contribute to global warming. Making use of that energy is much more efficient. Waste to energy does require some sorting of garbage but most of what is separated out can then be recycled and waste to energy plants are often on the same ground as recycling plants that can handle glass, metal and paper.