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โครงการหนังสืออิเล็กทรอนิกส์ด้านการเกษตร เฉลิมพระเกียรติพระบาทสมเด็จพระเจ้าอยู่หัว

Chapter 8

Application of water footprint and water stress index for water resources

management

This chapter shows the application of water footprint and water stress index for assessing

the sustainability implications of the bioethanol policy mandate in Thailand on water. Water

requirements for cassava, molasses, and sugarcane based ethanol production in various provinces
where bioethanol plants are located are evaluated using the water footprint (WF) concept and
expressed in terms of sources i.e. green and blue water. Also, the environmental impacts of

freshwater use for bioethanol production in life cycle assessment (LCA) are assessed in terms of

the water deprivation potential using the Water Stress Index (WSI) developed specifically for the 25
main watersheds in Thailand. The integration of both WF and water stress index approaches is
expected to help policy makers especially the Royal Irrigation Department (RID) of Thailand to

understand the impacts of bioethanol production on water use and stress and support them to

develop measures to minimize water use and to manage the water resources effectively.

8.1 Bioethanol production in Thailand

The Thai government has promoted the use of alternative energy as a national agenda
since 2004 especially bioethanol derived from the local feedstocks such as molasses, cassava,

and sugarcane. The promotion of government has spurred bioethanol production in Thailand from
0.3 M.litre/day in 2006 to 1.3 M.litre/day in 2011 (DEDE, 2012b). This growth is inclined to continue

as per the ambitious goal of the recent “Alternative Energy Development Plan: AEDP 2012-2021”
which set to produce 9 M.litre ethanol/day by 2021. However, the proliferation of bioethanol

production promises to increase stress on water and pressure on water resources beyond the
natural restoration capacity as agriculture currently consumes 73% of active freshwater storage in

the country (RID, 2012b). This is of particular concern because Thailand has a large agricultural
base both for food for local consumption and export as well as for feed and fuel.

As of December 2012, there are 19 ethanol plants in operation with total production

capacity of 3.07 M.litre/day. These consist of 13 molasses ethanol (MoE) plants (with a total
capacity of 2 M.litre/day), 5 cassava ethanol (CE) plants (0.78 M.litre/day) and a sugarcane ethanol

(SCE) plant (0.2 M.litre/day). The number of ethanol plants in operation is likely to increase in the
coming years as nowadays several new plants are under construction, especially cassava ethanol

plants (Preechajarn and Prasertsri, 2012). Meanwhile, 48 ethanol plants are registered with the
government with a total production capacity of about 12.5 M.litre/day consisting of 15 MoE plants,

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