We review research on growing and burning herbaceous and woody energy plants, and compare the harmful substance emissions into the air while burning these plants. Research results of biomass combustion and reed usage as an environmentally-friendly fuel grown near lakes is reviewed. The research results of burning the chopped energy plants such as willow and topinambour stems are presented, and compared with ash wood burning. The tests were carried out in a boiler designed to burn wood, wood briquettes, and large chips. After determination of harmful substance emissions into the atmosphere it has been concluded that burning bio-fuels is better because of low pollutant concentrations compared to wood, and sufficiently to coarsechopped willow stems, i.e. to those types of bio-fuels that are amply mixed with air while burning.