By the use of the plant described above, the farmer did not need to pay 350 bahts a month (100 bahts = 2.85 US$, as of December 2006), which was the cost of propane gas. This was a fair amount for a farmer’s family, and they said that they were happy with the reduction of this cost.

The fermentation residue was placed in a bag by 30 kg and sold at 12 bahts per bag.

The system was quite simple, and the plant

could be fabricated by villagers in 9 days. The material cost 5,000 bahts and total cost was 7,400 bahts, so the economic payback period was 21.1 months. A person from the local government who knew the know-how could help the farmer for building. The means to make the process economically feasible is simple structure and free labor to help each other in the village. The materials are cheap. No special skill was needed for operation, the main body of operation is farmers themselves, and this reduces the labor cost. The simplicity results in no necessity of operation person or labor cost, and farmers themselves can construct the plant.

Incidentally, income of farmers living around an ethanol production plant in Thailand is discussed here (Fig. 6.5.2.). The plant is planning to construct a 100,000-L/day ethanol plant and its feedstock is assumed to be cassava. It is because the market price of cassava is rather stable than that of molasses. The farmers could not get income when the plant used molasses
since the plant paid to sugar production factories. Therefore, the plant thinks that increase in the ethanol production from cassava will make cassava cultivation more attractive and people in rural area remain. The unit price of cassava chips is now 3.7 bahts/kg. In order to sell cassava to the plant, farmers have to chip and dry (below 18% of water content) for pretreatment. Considering this, they can earn 1 baht/kg and this profit is quite attractive for them.

There are mainly two ways to support farmers. One is to supply energy so that they have the access to useful fuels. In Thailand, small-scale biomethanation provides cooking gas to farmers, so they need not to buy propane gas for cooking. This support to farmers is also effective for sustainable agriculture due to the reduction of fossil fuel utilization. The other support is by cash. When they grow feedstock for ethanol production and sell it at a higher price, they can get money for buying electricity. Since those who use ethanol as fuel are richer compared to farmers, this mechanism can be considered as ‘redistribution of wealth.’