Tips to Save Energy with Variable Speed Drives

In today’s energy-conscious world, industry is increasingly focused on finding ways to reduce energy consumption, lower costs, and improve energy efficiency. One often overlooked solution is the use of variable speed drives (drives). In this article, we will explore how these versatile devices can help a variety of UK, public and private facilities save energy, reduce costs, and protect the environment.

A variable speed drive is an electronic device that controls the speed, direction and torque of an electric motor by varying the frequency and voltage supplied to it. By doing so, drives can significantly reduce the energy consumption of motors, particularly those operating fans and pumps. Here are someof our tips to save energy with variable speed drives:

1. Run motors slower for longer.

One of the most straightforward ways to save energy with variable speed drives is to run motors at a slower speed for a longer duration. When a motor operates at a lower speed, it consumes less energy. By running the motor at a slower speed, it can still perform the required tasks, albeit at a slower pace, which can lead to significant energy savings in the long run.

For example, in a pumping application, a motor running at 80% speed uses only 50% of the power required to run at full speed. This means that even though it takes twice as long to pump the same amount of fluid, the energy consumption is substantially lower.

Why does running motors slower for longer save energy?

To answer this, you need to understand cube law and how it applies to pumps and fans. Cube law is a fundamental principle and explains how energy consumption in pumps and fans is related to their speed. In simple terms, the cube law states that the power consumed by a pump or fan is proportional to the cube of its speed. This means that even a small reduction in speed can lead to a significant decrease in energy consumption.

For example, if a pump is running at 100% speed and consumes 100% power, reducing the speed to 90% will result in a power consumption of 72.9% (0.9^3 = 0.729). This represents a 27.1% reduction in energy consumption for a mere 10% reduction in speed. The cube law underscores the importance of using variable speed drives to control the speed of pumps and fans. By adjusting the speed of these devices to match the system requirements, businesses can achieve substantial energy savings without compromising on performance.

2. Use a variable speed drive to stop (and start) the motor completely when not in use.

Another effective way to save energy with variable speed drives is to use the drive to stop and start the motor completely when it’s not in use. Traditional motor starters will heat up the motor, so starting frequently is likely to burn the motor out. This isn’t an issue with a variable speed drive, so you can afford to stop the motor when it is not in use.

By stopping the motor when it’s not required, businesses can achieve significant energy savings and reduce wear and tear on the motor, prolonging its useful life.

3. Regularly maintain and optimise your variable speed drive.

To ensure optimal energy savings, it’s crucial to maintain and optimise your drive regularly. Regular maintenance can help prevent unexpected breakdowns, minimise downtime, and ensure the drive operates at peak efficiency.

Maintenance tasks include cleaning and inspecting the drive, checking for loose connections, and ensuring the cooling system is functioning correctly. Furthermore, periodically reviewing and optimising your variable speed drive settings to match the system’s requirements can lead to additional energy savings. We often see that original settings have been changed, so it is worthwhile periodically checking these.

In Summary – Tips to Save Energy with Variable Speed Drives

Variable speed drives offer a practical and cost effective way to save energy, reduce costs and contribute to carbon reduction. By running motors slower for longer periods, using drives to stop and start motors when not in use, understanding the cube law for pumps and fans, and regularly maintaining and optimising variable speed drives, businesses can significantly reduce energy consumption without sacrificing performance.

Moreover, the benefits of implementing drive technology extend beyond energy savings. By controlling motor speeds, businesses can enhance the overall efficiency and lifespan of their equipment, leading to reduced maintenance and replacement costs. Additionally, smoother motor operation reduces stress on mechanical components, resulting in less wear and tear and improved reliability.

With the UK government’s continued commitment to reducing carbon emissions and promoting energy efficiency, now is an ideal time for businesses that have applications powered by electric motors to explore the advantages of variable speed drives. By embracing this technology, you can make substantial strides towards meeting your energy-saving goals and future-proofing your operations in an increasingly competitive and environmentally-conscious marketplace. Want to chat? Call us on 0115 944 1036 or email [email protected]