Hybridization of anaerobic digestion with solar energy: A solution for isolated livestock farms

Abstract

Intensive farming causes an important amount of greenhouse gas emissions. This scenario can be significantly reduced by the implementation of renewable technologies and transforming farms from energy consumers to energy providers. In the particular case of livestock production, biogas and solar energy reduce greenhouse gas emissions and the energy demand of the installations. However, the implementation of these technologies requires solutions adapted to local scenarios, such as connectivity to the energy grids. In this work, a biogas/biomethane production system, energetically covered with hybrid solar panels is proposed as a solution for isolated areas where biodegradable substrates (manure) are abundant. Thus, the electrical and thermal requirements of the digester are supplied by solar panels, reducing the biogas self-consumption and the energy inputs from the electrical grid. Hybrid solar panels also provide sufficient energy for operation of an upgrading system to obtain biomethane of fuel vehicle quality, increasing the energy self-sufficiency of the agricultural activities. This solution has been simulated in five different climatic regions corresponding to areas of intense pig farming activity. The results demonstrate the sustainable bioenergy production in isolated farms with limited connection to the energy grid and organic matter availability. Furthermore, the economic study showed that the proposed technology is competitive compared to other technologies in the energy sector.