Degradation problem in the waste to energy plants, based on various different types of waste as fuels is very serious and still require technological solution in order to improve their efficiency. This study found that in the aggressive environment of waste to energy plants, different coating compositions with the different techniques tested, still did not give the desired results at the elevated temperature and still these plants, are running at very less efficiency as compared to fossil fuel based power plants. It is found from the previous work that the spray coating like APS, HVOF, HVSFS, Cold Spray coatings reduce the surface degradation in the diesel engines, gas turbines, coal gasification plants and chemical plants. Now a days nano-coating give good results to increase the life and performance of surfaces. Nano scale materials have achieved much attention in recent years due to their outstanding properties compared to those of micron-size counterparts. It is found that particle size strongly influences the particle thermal history as small particles rapidly heat up and also rapidly cool down. It also affects the interlamellar adhesion of the splats and hence influencing the mechanical properties of the coating. But the main hurdle in the nano powder coating is that nano-powders are expensive and not available in the market easily and in bulk. So a suitable method has to be found out to manufacture nano-powders in bulk and less expensive, so that they can be used as commercially viable coatings on the surfaces. This paper reviews the previous research work to understand the reason of less efficiency of the WTE plant and different preventive measures used to increase the efficiency of these plants.