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.