Step 1: Basic Design

• Reducing wastewater flows, e.g. by separation of rain water or by avoiding of sewer infiltration;
• Correct plant dimensioning, particularly avoidance of over-sizing;
• Selection of energy-efficient treatment processes.

Step 2: Detailed Design

• Selection of energy-efficient equipment;
• Use of correctly sized and energy-efficient drives and motors;
• Implementation of control systems matching supply and demand;
• Good thermal insulation where heating energy is externally supplied.

Step 3: Integral Energy Management

• Use of the entire digester gas for power-heat-cogeneration (PHC);
• Use of surplus anaerobic digester capacity for additional gas generation from imported organic waste;
• Efficient use of heat, e.g. recovery from processes or wastewater effluent;
• On-site sludge drying and incineration with energy recovery and reuse;
• Use of natural gas in PHC systems where heat is in short supply;
• Use of renewable energy, e.g. wastewater heat, wind or solar energy.