The first part of the paper describes the energy situation in the Republic of Croatia related to renewable energy sources regulated and prepared under the roof energy laws and the directives of the European Parliament and the Council on the promotion of the use of electricity produced from renewable sources. The market situation in Croatia is in the constant development of new plants that produce renewable electricity, among them biogas plants. Biogas plants use animal excretion and silage as raw material and in fermenters the same raw material is fermented and obtained biogas. By burning the biogas on the engine that drives the generator they get electricity and heat energy. Measuring equipment in the biogas system is extremely important both for the safety aspect and for quality control in automation systems. The choice of instrumentation depends on the various applications within the plant and the media being measured Key words: renewable sources, biogas plant, measurement, instrumentation