© 2013 John Wiley & Sons Ltd
Edited By: Steve Long
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Online ISSN: 1757-1707
Associated Title(s): Global Change Biology
Energy Crops Can Solve China's Energy Demands
China is the world’s largest producer and consumer of coal. Coal firing accounts for ~70% of China’s total energy consumption. Raising crops to produce renewable energy is a relatively new concept in China; renewable energy (excluding hydroelectric) accounted for only 0.2% of China’s total energy consumption in 2008. Nevertheless, China recently announced plans increase non-fossil fuel energy consumption to 15% of the energy mix from 2010 to 2020 (www.eia.doe.gov).
There is concern that bioenergy crop production may compete with food crops for land and irrigation, cause land use change, and result in a relatively low net energy gain. China does not have excess arable land to grow bioenergy crops because that land is used to feed its large population.
However, second-generation energy crops, which are capable of growing on marginal land that is not suitable for food production, may solve China’s energy needs. Marginal and degraded land that is under serious threat of desertification, of which China has an abundant supply, can be restored by the growth of energy crops, resulting in high net energy output and little to no CO2 emission.
Sang and coauthors identify Miscanthus as an ideal second-generation energy crop for China because native Miscanthus species are present across China’s climatic zone. This decreases the potential problem of invasiveness and provides enormous genetic resources for crop domestication and improvement. Miscanthus has high biomass production, land and nutrient use efficiency, drought tolerance, and carbon sequestration compared to many other candidate energy crops. Furthermore, Miscanthus requires less energy and machinery to harvest and dry.
While the production of ethanol from second-generation energy crops is still not economically feasible, biomass can be combusted or co-combusted with coal to generate electricity. Biomass combustion can be done at existing coal-firing power plants with moderate technical and equipment modification. The authors calculate that a reasonable near-term goal is to produce 1 billion tons of Miscanthus biomass annually from ~100 million hectares of marginal and degraded land. This can generate enough electricity to account for ~45% of China’s electricity output and mitigate ~28% of CO2 emissions in 2007.
Sang T, Zhu W (2011) China’s Bioenergy Potential. GCB Bioenergy, 3-2, 79-90. Read this paper.