Mapping Distribution and Range Analysis of Biogas Digester Units Using Nearest Neighbor Analysis Method in Sruni Village, Indonesia

Biogas represents a promising renewable energy source due to its dual function in waste management and energy production. This study maps the spatial distribution and evaluates the service coverage of biogas digester units in Sruni Village, Boyolali, Central Java, Indonesia, using Geographic Information System (GIS)-based analysis. Data on 89 biogas installations were collected via GPS and Google Earth Pro. Nearest Neighbor Analysis (NNA) and buffer analysis (25–250 m) were conducted to assess spatial patterns and accessibility. The NNA results indicate a clustered distribution pattern, with a nearest neighbor index (T) of less than 0.7, a z-score of -8.061642, and a p-value of 0.000000, confirming a statistically significant clustering at the 99% confidence level. Buffer analysis reveals that current installations only cover 2.46 km² (74.77%) of the total 3.29 km² village area, highlighting a disparity in access to biogas services. Most digesters are concentrated in central hamlets, particularly Sruni, Tegalsari, and Tugusari, influenced by early local initiatives and livestock density. The study provides valuable insights for equitable biogas infrastructure planning in rural Indonesia and underscores the role of spatial tools in optimizing renewable energy distribution.