Energy analysis of Jatropha plantation systems for biodiesel production in Thailand Kritana Prueksakorn a , Shabbir H. Gheewala a, ⁎, Pomthong Malakul b , Sébastien Bonnet a a The Joint Graduate School of Energy and Environment, King Mongkut's University of Technology Thonburi, Bangkok, Thailand b The National Metal and Materials Technology Center (MTEC), National Science and Technology Development Agency (NSTDA), Thailand abstract article info Article history: Received 10 June 2009 Accepted 23 December 2009 Keywords: Biodiesel Jatropha Net energy balance Net energy ratio Thailand Jatropha curcas L. has been considered as a potential feedstock for biodiesel production in several tropical countries. Two Jatropha plantation models currently being considered in Thailand, a perennial plantation for 20 years and annual harvesting, are compared vis-à-vis the energy benefits. The advantage of the perennial plantation is that fruit yield is low in the first 2 years but stabilizes after the second year; thus, the biodiesel production is maximized. On the other hand, the biodiesel yield for annual harvesting is low but substantial energy is gained from the wood which can be used for power production. The overall energy output from the annual system is about twice that of the perennial system whereas the biodiesel production is less than half. The energy values of both the systems are high and the net energy ratios as high as 6–7 indicating a substantial energy benefit. © 2009 International Energy Initiative. Published by Elsevier Inc. All rights reserved. Introduction Thailand is an agricultural country with high potential for energy crops which could contribute to reduce its reliance on import of fossil energy resources to satisfy its demand. In 2004, the country energy demand amounted to 61.080 ktoe (25 billion USD), with the transportation sector contribution the largest share (35%) of the total energy demand (Sailasuta, 2006). In 2000, the cost of the imported oil was 258,172 million baht (1 USD = 35 Thai Baht) out of which 12,133 million baht was paid for the importation of diesel oil, an important factor of production in the industrial, agricultural and transportation sectors. Biofuels–biodiesel and bioethanol–are being promoted by the government of Thailand to partly address the above issues. The target is to have the 5% biodiesel blend (B5) by the year 2007 and B10 in 2012 (Sailasuta, 2005). Even though palm oil is the major feedstock for biodiesel production in Thailand, Jatropha curcas L., hereafter referred to in the text as Jatropha, or Physic nut is considered as one of the other promising energy crops. Although it produces lower yields of oil than oil palm, it has been reported that Jatropha has several advantages including being able to grow on poor land (arid and marginal land), improving soil quality, requiring small amount of water, fertilizer, and pesticides and providing several by-products from the production of Jatropha biodiesel such as wood, fertilizer and glycerin (Prueksachat, 2006). The government of Thailand is emphasizing palm oil for the moment as the feedstock for its biodiesel program (up to as much as 90%) and a minimal role for Jatropha because there is more experience with the productivity of palm oil as a proven crop in Thailand as well as uncertainties over the cost and availability of raw materials for Jatropha. The government has encouraged research and development before commencing commercial planting although some private sector entrepreneurs have already started cultivation. Research institutes are also rapidly developing high-yielding varieties of plants for various regions. The present plan is to use micro-capacity locally developed batch process refineries for Jatropha crude oil for local community usage (Kittiyopas and Ladawan Na Ayudhaya, 2006). Several models for Jatropha plantation based on farm size, cropping systems and ownership have been proposed. These include not only using the Jatropha oil for biodiesel production, but also the use of biomass from the Jatropha plants for energy and the seedcake from biodiesel production as fertilizer. Conventionally, long-term plantation of Jatropha has been considered because it is a perennial crop. However, the high price of Jatropha oil, 3–10 times higher than that of diesel production, makes this option quite difficult to commercialize in the current situation in Thailand (Openshaw, 2000). Another option could be to utilize the wood, peel, seed cake, etc. as co-products having a substantial economic benefit(Kittiyopas and Ladawan Na Ayudhaya, 2006; Openshaw, 2000; Gubitz et al., 1999). This option is feasible due to the fast growth of the Jatropha plant and its ability to yield fruit since the first year (Foidl et al., 1996). In this study, two plantation models—a perennial plantation for 20 years and annual harvesting are compared vis-à-vis the energy benefits. The advantage of doing such a comparative energy balance is that it is an important indicator also of economics as well as greenhouse gas (GHG) balance as a large part of the costs and GHG emissions in biomass systems are related to fossil energy uses and savings (Von Blottnitz and Curran, 2007). It is thus an important first step for supporting policy as well as commercialization of any bioenergy source (Nguyen et al., 2007). Energy for Sustainable Development 14 (2010) 1–5 ⁎ Corresponding author. Tel.: +66 2 470 8309; fax: + 66 2 872 9805. E-mail address: shabbir_g@jgsee.kmutt.ac.th (S.H. Gheewala). 0973-0826/$ – see front matter © 2009 International Energy Initiative. Published by Elsevier Inc. All rights reserved. doi:10.1016/j.esd.2009.12.002 Contents lists available at ScienceDirect Energy for Sustainable Development