Energy in Glass Processing




UK Government Environment and Energy Helpline 0800 585 794

Robin Kent - Tangram Technology Ltd. 

 Reducing Energy Costs

Increasing energy costs will be a feature of running a business for the foreseeable future. The 'Climate Change Levy' and rising generation costs will ensure that energy becomes an ever more important cost to industry. 

Despite this, the glazing industry generally regards the energy as an overhead and a fixed cost. Nothing could be further from the truth. Energy is both controllable and a variable cost. Most systems suppliers and fabricators could easily reduce their energy costs (without substantial investment) and increase their profits. Energy management through simple good management can save real money.

So why aren't you managing your energy costs instead of simply ignoring them and treating them as somebody else's problem?

''Energy is a controllable cost'

Understanding energy usage

Before you can reduce your energy costs you need to understand the basics of your energy use. You need to understand:

Where you are using energy?

The main users of electricity in the glazing industry (in rough order of importance) are motors and drives, heaters and lighting systems. A simple map of site energy distribution will show where energy is being used. If you are using a single meter, it may be cost effective to install sub meters to get further information on the areas of high energy use. Sub metering allows calculation of the cost of energy for each operation and identification of areas of high energy usage - a key factor in reducing energy costs.

When you are using energy

The time that you are using energy is important in the cost of energy and a simple chart of the demand (at 1/2 hour intervals) plotted versus time will give invaluable information on how to reduce the energy costs. Peaks of energy usage at the start of the day will increase the energy cost for the complete day. A demand graph also will allow assessment of the 'base load'. Reducing the base load is a sure way to make savings.

Why you are using energy

Knowing when and where you are using energy will start to reveal why you are using energy. Is it being used to keep machines idling when they should be turned off? Are heaters running that are not being used? Are compressors running just to pump air out of leaks?

How much energy you are using

Knowing how much energy you are using will allow you to start to reduce your energy costs. Electricity charges are made up of several factors and supply companies vary charges based on these factors. An initial survey of the company will reveal areas for potential savings - sometimes you are simply on the wrong tariff and a change in the tariff can save large amounts of wasted money at no cost!

Practical tips

Administration and management



Record and monitor water usage. Water may seem cheap but you pay for it twice - once to buy it and once to dispose of it. The total cost can generally be reduced by 10%, this is up to 1000 per year and is better on the bottom line than down the drain.

Compressed air

Compressed air is an expensive resource. Minimise the demand, then optimise the supply.

A 3 mm hole in a 7 Bar main will leak about 11 litre/sec, at a cost of about 1,000 per year for a 120 hour working week. What is your total leakage? Reduce your costs by sealing the leaks. All it takes is a sensitive ear to hear the leaks, a cup of water with some detergent and a brush. See the bubbles and see the money.

The higher the pressure, the more expensive it is to provide compressed air. Twice the pressure means four times the energy cost. What are your real needs? Remember that the longer the pipeline, the greater the pressure loss over the pipeline and the greater the cost.


Buildings are large energy users. A simple site survey can reduce your costs considerably. 


Motor and drives

The energy costs of a motor will exceed the purchase cost in just 40 days and 'life costs' are over 100 times the purchase cost. Fit more efficient motors that are matched to the need and use low cost 'soft start' and variable speed drive technology to reduce costs.

Invest in devices that limit peak loads.

Energy Efficiency - Free Resources for Glass and Glazing

Helpline: 0800 585 794 - Call the Helpline to get free copies of all books, software and videos and to arrange consultancy visits.



Energy ManageMent Advisor (EMMA) - A software tool to examine energy use in businesses.

'Quickstart' - a software tool to analyse the energy efficiency of existing motors.


Ask for the Publications List to see what else could be useful to your business. It is all free.

Publications List

Publications list to see what else could be useful to your business.

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Consultancy Visits

Free consultancy visits are available to small to medium companies who meet certain conditions. Contact the Helpline for details.

Last edited: 21/02/12

Tangram Technology Ltd. 2002

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