Frequency inverter, the best energy saving solution

This paper explains how technologies that are already at our disposal, such as frequency inverters, can still deliver huge energy savings.

In the emerging low carbon economy, there are many voices suggesting different ways of keeping the energy supply secure and sustainable. As a result, the simple frequency inverter message is in danger of being smothered by renewable energy debates, nuclear generation concerns, smart grids, feed-in tariffs and a pethora of blue-sky, out-of-the-box, wheel-reinventions.

There is no doubt that we need to develop sustainable forms of generation, whatever the source. In fact, developing new technology is fundamental to providing innovative solutions to the global energy problem. However, as well as finding ways to keep the lights on, we should start by turning lights off when are not needed. With the serious threat of energy rationing on the 10 year horizon in China, using less energy is a smart move from both a cost and continuity perspective.

Installing a frequency inverter on industrial motors remains one of the best and most straightforward ways of reducing energy usage, particularly when driving pumps and fans. Frequency inverters can cut the energy bill on an application or system by more than their own capital cost in a relatively short period.

As electricity prices continue to rise, the return on investment (ROI) on a frequency inverter application increases in proportion to the bill. Furthermore, because the cost of a frequency inverter has actually remained stable over the last decade, payback can be more quickly achieved, often in less than a year.

Considering lifetime costs
It is worth remembering that 90% of the lifetime cost of an electric motor comes from its energy consumption. This can be illustrated by the fact that if just half of a country's electric motors were reduced in speed by 10%, it would have the net effect of mitigating for the carbon emissions of 9.8 million executive saloon cars every year.

So, the energy cost of a system should be the first thing a buying team looks for in a quote as it may well be the single item that most effects the bottom line over time. This is particularly true in process applications, where pumps and fans are widely used for liquid and air movement. Turning their speed down by 20% can translate to a 50% energy saving in a fan controlled by frequency inverter.

Energy consumption is exacerbated by the fact that motors are often over specified in process industries, so they can cope with worst case scenarios. Adding a frequency inverter will not remove this ability to manage in extremes, it will just reduce its cost on a day to day basis.

The cost of energy is important, but its security and continuity is crucial for sectors such as oil, sewage or petrochemicals. Maintaining a reliable energy supply requires both businesses and individuals to consume less – and this is exactly what frequency inverters can help process companies achieve.

It must also be borne in mind that frequency inverters are not the panacea to all problems. They are not suitable for all types of motor applications, so engineers should always consult the our website or other specialist resources provided by the supplier when specifying a frequency inverter.
If you are a purchase man, or working at management level for a process company that uses substantial amounts of energy, frequency inverters could be a viable solution for many motor applications.