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Product category: Industrial Drives/Controls
News Release from: Control Techniques | Subject: Variable speed AC inverter drives
Edited by the Engineeringtalk Editorial Team on 30 January 2001

Plan how to offset the Climate Change
Levy now

The Climate Change Levy is viewed by industry as an imposition, but it is also a stimulus to action, to be more energy efficient ...and with good reason

In 2001, British business is going to be hit with a savage increase in energy costs, currently estimated at 12% This is the result of an environmental initiative that is being introduced by HM Government

Known as the Climate Change Levy, its function is to deliver on the carbon reduction commitments made by the UK Government at Kyoto in 1997.

The levy is viewed by industry and commerce as an imposition.

True, it is a tax by any other name.

But, looked upon in another way, it is also a stimulus to action: i.e to be more energy efficient ...and with good reason.

Presently, a vast amount of energy is wasted annually by British Industry.

To illustrate this: almost 2/3 of industrial electricity consumption is accountable to the running of electric motors and drive systems, at a cost to consumer of £3 billion/per year.

Calculations show that as much as 40% of this energy is not used to perform the function required and is therefore wasted due to ineffective control.

What this figure reveals is that there is massive scope for savings right across industry.

And in many cases the savings accrued will easily offset the effects of the impending levy.

The question is: where to start looking for the savings? Fortunately, this is not difficult to answer because research and experience over the last 15 years has shown that fan and pump installations are one of the prime areas where wastage occurs.

Why is so much energy wasted? Around 40% of industrial electricity consumption is used to power the AC motors that drive pumps and fans.

The majority of these motors are driven at constant speed and, for reasons of low original cost, variation in the system output is frequently achieved by throttling or damping - an inefficient and imprecise method at best.

In addition to this, a substantial amount of this energy is wasted because most fan and pump systems are oversized, usually because of too much contingency planning in the system design.

To make matters worse, this is further compounded by the practice of rounding up to the next standard motor size.

Consequently, significant amounts of energy are expended unnecessarily, and the operating cost of the system can be as much as 50% more than it should be.

It doesn't have to be this way.

Substantial overall savings in energy and indirect costs can be realised relatively simply with the effective application of variable speed AC inverter drives.

A simple example illustrates this point effectively: using a variable speed drive to achieve a 15% reduction in fan motor speed can achieve as much as a 40% energy saving.

Unfortunately, at the present time, take up for AC inverter drive systems is scandalously low, considering the huge energy saving benefits to be gained.

Even when, as often happens, a two year pay back (why only two years, why not three, when the equipment has a 10 year life?) or less can be illustrated, the proposal to fit a drive system often fails to go ahead.

There are three reasons for this.

Firstly, the lack of resource at engineering level, where the proposal starts and all too often dies.

There may be a saving to be had, but the 'if it ain't broke, don't fix it' attitude means the project stays in the pending tray rather than moving into the action tray.

Engineering's job is to keep the wheels turning, not necessarily to reduce running costs.

Secondly, the main cash saving incentive resides with the finance department, which often doesn't know about the potential for energy saving, because no application is made for capital funding.

They also don't understand the technologies of fans, pumps or drives and frequently find it difficult to believe such substantial savings can be made.

Finally, there is the reluctance of British business and commerce to dip into the capital budget to save in the revenue budget.

Effectively, they believe they cannot afford to save money! Curiously, the appointment of Energy Managers in many large businesses does not seem to have stimulated the uptake of energy saving drives, despite the best efforts of the Energy Saving Trust and ETSU at their seminars.

A new initiative means that there is now a hope of overcoming the reluctance to spend on energy saving drives.

Control Techniques UK, working in partnership with Hyder Energy Services, have successfully pioneered an innovative mechanism for the supply of energy saving drives to industry and commerce.

Control Techniques survey the installation, act as project manager and supply the drives.

Hyder Energy Services fund the total initial project cost, recover the funding in stages over the payback period, and take a share of the energy savings.

This spreads the cost, reducing the capital commitment and links the cost more closely to the savings.

How can Control Techniques deliver energy savings? Control Techniques does not limit its energy surveys exclusively to its joint initiative with Hyder Energy Services.

When requested by large energy users Control Techniques will provide a specialist to conduct an on-site fan and pump energy survey.

Alternatively, it is simple matter for the user to conduct his own survey and calculate the anticipated savings using Windows based 'CTSAVE' software, which is available free upon request to Control Techniques.

Experiences in all types of industries and businesses show that it certainly pays to survey.

Below are two examples from the Control Techniques portfolio of case studies demonstrating the proven energy cost savings achieved by effective application of Control Techniques VTC inverter drives to fan and pump control.

Chiller Pump Running Costs Reduced By Over ?1,000 Per Month.

Site: DVLA Swansea.

Contractor: Planned Maintenance Regional Services.

Product: Control Techniques 160kW Unidrive VTC inverter drive system.

Project: Reduce the power requirement of the chiller water-circulating pump.

Options: Change the motor or introduce an inverter drive system to replace the pump star/delta starter.

Decision: Inverter drive system based upon Control Techniques 160kW Unidrive VTC System.

Result: Power consumption down from almost 160kW to 50kW, saving between 100kWh and 115kWh for 12-15hours per day, providing a pay back within 18 months of installation.

Summary: Control Techniques delivered, installed and commissioned the main and standby drives systems in only 16 hours.

The Control Techniques Unidrive VTC, has been designed to meet the special needs of fan and pump applications, and includes a dynamic voltage / frequency control feature which automatically optimises the voltage to the required load.

The consequence of this is additional energy efficiency as the motor flux is matched to the actual need.

39% of Energy Costs saved.

Site: Oxford Brookes University students union.

Product: Control Techniques Unidrive VTC inverter drive system.

Project: Reduce the power requirement of the air handling system, which uses two 25kW two-speed motors for extraction and supply of fresh air to the union.

Control improvements were necessary to provide an appropriate response to the number of people using the union facility.

New Control System: Control Techniques Unidrive VTC system, providing a continuous adjustment to fan speed.

Result: A considerably improved level of temperature and air quality control, plus a reduction in power consumption of approximately 60,000 kWh per year.

This will provide an annual saving of ?2,500 and pay back in just over 2.5years at current energy costs.

Summary: The Control Techniques Unidrive VTC system matched the motor speed to the requirements of the air handling system, resulting in a substantial energy saving, which was very close to the original theoretical calculations. Request a free brochure from Control Techniques ...

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