Forest Trees - Bioenergy Crop Plants - page 358

A sustainable forestry scenario aimed at meeting the projected biomass demands, halting defor-
estation, and regenerating degraded forests was developed (Ravindranath et al. 2001). Excluding
the land required for traditional fuelwood, industrial wood, and timber production, and consider-
ing only potential land categories suitable for plantation forestry, 41-55 million ha is available for
SRWCs. About 12 million ha is adequate to meet the incremental fuelwood, industrial wood, and
timber requirements projected to 2015. An additional 24 million ha is available for SRWCs with
sustainable biomass potential of 158-288 million t annually. Other estimates vary from 41-130
million ha. Marginal cropland and long-term fallow lands are also available for SRWCs. Assuming
a conservative 35 million ha of SRWCs producing 6.6-12 tons/ha per year, the additional woody
biomass production potential is estimated to be 230-410 million t annually, and the corresponding
total annual power generation potential, at 1 MWh/tons of woody biomass, would be 228-415 TWh
(Sudha et al. 2003), equivalent to 36.5-66.5% of total power generated during 2006 (623.3 TWh) in
India. Because the photosynthetic efficiency of forest trees, rarely above 0.5%, could be genetically
and silviculturally improved to 6.6% (Hooda and Rawat 2006), there is an ample opportunity to
improve efficiency up to 1%, thus doubling forest productivity.
Thus, biomass for power generation has a large potential to meet India's power needs sustainably.
The life-cycle cost of bioenergy is economically attractive compared to large coal-based power genera-
tion (Ravindranath et al. 2006). Clean biomass, coupled with other changes, could reduce GHG emis-
sions by approximately 640 MT CO 2 per year in 2025 (~18 % of India's emissions). Sustainable forestry
could increase carbon stock by 237 million Mg C by 2012, whereas commercial forestry could seques-
ter another 78 million Mg Carbon. The sustainable biomass potential of 62-310 million tons per year
could provide about 114% of the total electricity generation in 2000 (Bhattacharya et al. 2003).
Sustainable bioenergy potential has also been estimated for Malaysia, Philippines, Sri Lanka,
and Thailand (Bhattacharya et al. 2003). Sustainable SRWC production could be 0.4-1.7, 3.7-20.4,
2.0-9.9, and 11.6-106.6 million tons per year, respectively. Using advanced technologies, maxi-
mum annual electricity generation may be about 4.5, 79, 254, and 195% of total generation in 2000,
respectively. Biomass production cost varies from U.S.$381 to 1842/ha and from U.S.$5.1 to 23 tons.
15.2.1.4 australia
Australia has abundant energy resources, a dispersed population highly dependent on fossil fuel
based transport, and relatively fast population growth (Baker et al. 1999). Its total energy consump-
tion has recently increased by 2.6% per year and was estimated to be 4810 PJ in 1997/98. Australia's
per capita GHG emissions ranked third among industrialized countries and were projected to be
approximately 552 million Mg CO 2 -e in 2010, a 43% increase from 1990. In 1995/96, energy pro-
duction from renewable sources (~263 PJ) was mainly from bagasse (90.3 PJ), residential wood
(82.1 PJ), hydroelectric (54.8 PJ), and industrial wood (27.6 PJ).
Its biomass sources including bagasse, paper pulp liquor, forestry and wood processing residues,
energy crops, crop residues, and agricultural and food processing wastes may contribute signifi-
cantly to a 2% renewables target (Baker et al. 1999). Sugarcane, one of the least costly forms of
biomass, could alone meet the entire 2% target. Gasification of cotton-gin residues could generate
50 MW of electricity. Rice hulls could support approximately 5 MW of electricity.
The use of SRWCs for bioenergy in Australia is being explored. Interest in the establishment of
forest plantations on irrigated and nonirrigated sites in the southern Australia has increased (e.g.,
Bren et al. 1993, Baker et al. 1994, Stackpole et al. 1995, Baker et al. 1999). Municipal wastewater
systems are opportunities for bioenergy production, as land, irrigation infrastructure, and water
costs would be part of the total water treatment costs, not part of the costs of biofuel production.
The potential for wastewater-irrigated plantations for bioenergy production is evident in Victoria
(Baker et al. 1999). Assuming growth rates of 30 Mg/ha per year, approximately 400,000 Mg per
year could generate 50 MW. EG at Wodonga (irrigated with municipal effluent) and Kyabram (first
irrigated with freshwater and then groundwater) had growth ranging from 15 to 45 m 3 /ha per year
at 10 years (Baker 1998) when irrigation water salinity and initial soil salinity were not problematic.