Potential of poplar short rotation coppice cultivation for bioenergy in Southern Portugal.

This manuscript examines the potential of poplar short rotation coppice cultivation for bioenergy in the Alentejo region, Southern Portugal. The biomass is intended to fulfil, at least, 10% (energy basis) of the fuel needs of two Portuguese coal-fired power plants (Sines and Pego), using co-firing technology. The study considers the overall production chain from cradle to power plant gate, cultivated in scrubland areas with duration of 12 years, harvested every three years and with 6667 plants per ha, covering a land area of about 52,250 ha. Three different biomass annual yields are assumed. The results show that the biomass selling prices range from 76.9 to 120.5 Euro ton−1, to match the production costs. The net energy of the overall project ranges from 34.7 to 75.4 PJ and the project cost from 619 to 823.9 MEuro. The main environmental impact of the project is the reduction of the CO2 emissions due to the biomass co-firing, instead of burning coal alone. The power plants can reduce CO2 emissions over the project lifetime between 8.2% and 16.5% of the current values. The financial analysis demonstrates that the project is not financially feasible without external grants, but a policy scenario of carbon allowances trading may be instrumental on turning it financially feasible, depending on allowances and coal market prices. Finally, with a reduction of 50% in the main costs, the project becomes financially feasible under a CO2 emissions trading scenario for a biomass yield of 20 dry ton ha−1 per year.