German biogas plant specialist Weltec Biopower has made significant headway in Greece. In the last year, Weltec has built four further projects and expanded three existing plants in the country. Of 30 total Greek agricultural and waste biogas plants, Weltec has been involved in 17.
Its recent additions include an expansion to the Megara biogas plant, originally built in 2015. The area around Megara is known for keeping chickens, and the biogas plant is on the site of a chicken farm with 20,000 laying hens. As a result, some of the input materials are permanently secured. In addition to chicken droppings, roughly equal amounts of olive oil pomace, cattle and pig manure, and whey are used as energy production. Since the plant was expanded, the daily amount of the substrate mix has risen to 190 tons.
Originally the plant comprised a digester made of stainless steel with a volume of 3,993 cubic meters, a 530 kilowatt CHP and a storage unit. For the increased input volume, Weltec built another 3,993 cubic meter stainless steel digester with a height of 6.30 meters and a diameter of 28.41 meters. In addition, another pre-storage unit, a second 530 kilowatt CHP and an unpacking system for cheese and vegetables were installed. However, this unpacking system is only used in case of irregular deliveries of expired food. A solids feeder is not required since the pumpable substrates are brought into the storage units via a central pump block and then conveyed into the digesters.