Ключевые слова: alternative, bio, biofuel, biomass, burn, change, climate, close, combustion, commodity, compressed, costs, eco, ecological, ecologically, ecology, efficient, energy, environment, environmental, environmentally, fireplace, firewood, forest, friendly, fuel, grains, grow, heap, heat, heizkosten, home, hot, industry, mass, material, mining, pellet, protection, recycle, recycling, renewable, shavings, sources, stove, sustained, timber, warm, wood, wooden,