The increase of affordability due to the clustering of non-biogas farmers are assed in this study. The assessment aims to find out the most reliable manure biogas management in Peresak Village, Lombok Island which is located about 11 km east from Mataram, the capital city of West Nusa Tenggara Province. The village has 855 cows owned by 125 farmer households. However, only 5 households have been utilizing the manure waste as feedstock for anaerobic digester (AD) to generate energy for cooking. One of the hindrances in biogas management is the low affordability of the farmer to construct the AD. Therefore, the affordability of the farmer are measured under two different conditions, which are before and after clustering, to compare them.

The potential biogas production is also calculated after clustering with 2 diverse assumptions of biogas management which are based on the AD size and the number of cows. The number and location of the clusters was determined through spatial cluster analysis. There are totally 5 clusters comprising 120 households. Each cluster consists a number of houses depending on the proximity. The calculation shows that most non-biogas farmers cannot afford to construct AD individually, while clustering increases their affordability. However, the affordability of member in each cluster is influenced by the number of the cows and the size of the AD. Clustering increases the affordability of all farmers if they used the 4m3 and 6m3 AD. Yet, not all of the manure waste can be used as feedstock enabling the pollution risk consequently. On the contrary, if the size of the AD is determined by the number of the total cows they owned, only some farmers can afford the construction cost. Consequently, the biogas production potential is not optimum for the first assumption and maximum for the second assumption. Furthermore, the energy production from both assumptions come to the same result where the first condition produces more energy that the second condition which is 48.89 kWh/h and 27.19 kWh/h respectively.