Crops specifically grown for energy biomass include short rotation coppice with willow (Salix sp.) and poplar (Populus sp.), perennial grasses miscanthus, switchgrass (Panicum virgatum), reed canary grass (Phalaris arundinacea) and giant reed (Arundo donax).

Coppice has been used in Europe for centuries with long rotations of 10-30 years using hazel (Corylus avellana L), black alder (Alnus blutinosa L), and to a lesser extent oak (Quercus robur L), ash (Fraxinus excelsior L), elm (Ulmus sp.) and horn­beam (Carpinus betulus L). Latterly non-indigenous species have been used. In the coppice system the stems are cut back at close to soil level after 3-10 years. This encourages the growth of a large number of stems which can be harvested after 3-4 years in the case of willow and poplar. The other species have a slower growth rate and will be harvested after 10-30 years. Table 4.2 gives the yield and energy content of the short rotation coppice species. Willow and poplar yield between 6 and 17 t/ha/ year with a calorific value of 15 GJ/t. Plantations of 15,000 cuttings/ha for willow and 10-12,000 cuttings/ha for poplar are planted in winter or spring. After 1 year the single stem is cut back to soil level to produce a multi-stemmed stool which can be harvested every 3-4 years. Harvest is mechanical and the stems chipped and dried for combustion. Willow is the preferred species in the UK, where the plantations can last for 25-30 years. Much of the biomass is co-fired with coal in power stations.