The water and wastewater industry is one of the largest energy consumers in the public sector. Energy costs are one of the biggest cost factors. Especially when pump systems are in operation for more than 2000 hours a year.
The generation of this energy produces around 3 million tons of CO2 every year. In the long term, however, the municipalities and operators are aiming for CO2 neutralization in this sector. To achieve this goal, they must rely on modern technologies and optimized operating procedures. The 10-30-60 rule helps to implement these energy savings. It is based on empirical values and states that 10 percent can be achieved with more efficient components such as energy-saving motors, and a further 30 percent through the use of frequency converters. Operators can only achieve the last 60 percent – and thus the highest savings – by optimizing the overall system. Centrifugal pumps and fans are particularly suitable for achieving this reduction in energy consumption and thus CO2 emissions, as they offer the greatest savings potential due to their square and cubic characteristic curves.
They belong to the group of turbomachines with a quadratic torque curve, which means that the flow rate increases proportionally with increasing speed, the pressure increases quadratically and the energy absorption increases to the third power. This is where frequency inverters come into play. Their task is to adapt the system performance precisely to the respective requirements. And – in contrast to a mechanical control system such as a throttle control, for example – it reduces energy consumption and thus greenhouse gas emissions. This is because they control the speed of the motors, optimize the magnetization and can control all motor types, such as asynchronous, permanent magnet or synchronous reluctance motors. A positive side effect: they simplify commissioning and thus reduce installation costs.
