Conventional biodigesters were first promoted in Peru during the 1970s. At the time, the aim was to produce energy from livestock manure as an alternative to fuelwood consumption, which was contributing to rapid deforestation. However, many years of concerted efforts did not lead to any widespread adoption. There were many reasons for this: the biodigesters promoted were based on Chinese and Indian models that had been developed under very different social and cultural conditions, and there were no efforts to involve the Peruvian farmers in further development or adaptation. The construction was also relatively complicated and construction costs were high. In addition, most small-scale farmers did not have enough manure available to keep these biodigesters in operation, as most livestock grazed freely on rangeland.
The main objective for introducing this technology had been the production of biogas for energy purposes and no attention was paid to the by-products of the digesters – the effluent and the slurry remaining after decomposition. For many years, this way of thinking prevented further development and promotion of the technology.
