Page 112 -

โครงการหนังสืออิเล็กทรอนิกส์ด้านการเกษตร เฉลิมพระเกียรติพระบาทสมเด็จพระเจ้าอยู่หัว

brings about a drastic reduction in blue WF per litre of sugarcane ethanol from 490 to 72 L water/L
sugarcane ethanol. Nevertheless, the calculation above is based on the official irrigated areas

reported by RID; but in reality, some farmers outside the official irrigated areas also use water
supplied from other sources for their plantations and also some farmers may use deficit irrigation

for which the field survey for the critical watersheds needs to be conducted in the future. However
at present, there are no official irrigated areas of cassava plantation in Thailand (Damen, 2010).

8.4.3 Implications of the bioethanol policy mandate on water use and stress

The study assesses the potential impacts on water use and water stress with respect to the
policy mandate of bioethanol production in Thailand. Two scenarios are developed including:

Scenario 1: Policy mandate scenario—the scenario assumes that the AEDP’s target of producing 9

M.litre ethanol/day by 2021 will be satisfied by the 48 licensed ethanol plants. The scenario

assumes that only molasses, cassava and sugarcane juice are the feedstocks. All 48 ethanol
plants licensed by the government can start operation in accordance with the proposed schedule

and the ratios of feedstocks used for the 8 multi-feedstocks bioethanol plants are assumed on a
50/50 basis by sharing between the molasses and cassava. To satisfy the target of 9 M.litre

ethanol/day, the ethanol plants are assumed to operate at 72% of their production capacities;

Scenario 2: Full production capacity scenario—the scenario assumes that all 48 plants will be

operated at the full production capacity i.e. 12.495 M.litre ethanol/day. Thus, production of 4,560
M.litre ethanol/year would be the mandated bioethanol target of this scenario. The future changes
in yields of cassava and sugarcane per hectare are neglected in the assessment as there are

many factors e.g. climatic conditions, agricultural practices, future varieties development affecting

the crop yields.

The results show that, to satisfy the AEDP bioethanol target in year 2021, around 8,185
3
3
3
million m /year are required with 6,560 million m rain water (80%) and 1,625 million m irrigation
water as shown in Table 8.4. In addition, if the ethanol plants were fully operated as per the
Scenario 2, the demand of irrigation water to fulfill the ethanol production would be increased to
3
2,256 million m in 2021. The blue water requirements for Scenarios 1 and 2 are equivalent to
about 3% and 4% of the active water storage of Thailand in year 2012 which is around 55,268

3
3
million m . About 60% of the total blue water requirements i.e. 958 million m would be for cassava
ethanol production.

Page | 75