Extract from the reference list:

Energy crops:

• Biogas Alerheim OGH, Germany
• Biowatt, Austria
• Biogasanlage Seidenfus, Germany

Bio-waste / expired (packed) food:

• Bioenergie Schlitters, Austria
• Landkreis Böblingen, Germany
• Biofutura, Slovenia
• Bio Energie Centrum, Germany