Energy efficiency in manufacturing (durable)

There is a considerable amount of energy consumed in the manufacturing sector, so any steps you can take to be more efficient will almost definitely give you a direct improvement on the bottom line.

You might be taking some of these measures already, but to make it easier, we’ve split them into no cost, low-cost and investment-based changes.

Being proactive about energy efficiency measures and taking steps to reduce your consumption could result in bills that are 18-25% lower, getting your investment back in less than 18 months.

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Who is this for?

Simple no cost changes

compressed air icon

Compressed air

  • Identify whether compressed air is really needed for certain tasks. For example, could air blown from a fan do the job cheaper? Additionally, using cordless tools instead of tools powered with compressed air is far cheaper.
  • Remember to switch it off – an idle compressor uses 40% of its full load.
  • Regular maintenance can increase efficiency by up to 10%.
  • Check for leaks – it’s an issue that is estimated to affect 30% of industrial sites. One way to check is to listen in silence. Alternatively, use soapy water and see if it comes out. You can find more detailed instructions in this Carbon Trust guide.
  • A 3mm hole could cost you £4,000 in leaked compressed air.
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Motors and drives

  • Switch off motors when not required rather than keeping them idle.
  • Look for opportunities to reduce the load on pumps and fans.
  • Lowering the speed of a motor by just 20% can save up to 50% energy, so judge the speed needed by the situation.
  • If you turn off a 4kW motor for an hour a day, you could save about £114 per year. If you do the same with a 50kW motor, the saving goes up to £1,425.
Heating energy efficiency

Heating

  • Regularly check the thermostat, taking into account occupancy and seasonality. 1°C reduction can lead an 8% cost saving. Turn the heating down by 2°C could save you £140 on a £1,000 bill.
  • Check the boiler regularly. If it’s broken it will have warning lights, pressure drops, burn marks or make more noise than usual.
  • Regularly check for leaks or issues with the insulation in the steam distribution network from traps, pipework and joints. 10% of the heat produced by steam boilers can be lost through inefficient insulation.
Ventilation and air energy efficiency

Ventilation and air circulation

  • Check that extraction fans are not left running unnecessarily, even if it’s just for a short break. Encourage staff to turn off ventilation when not needed.
  • Take advantage of natural ventilation and free cooling where possible and minimise the use of air conditioning by limiting sources of unexpected heat like office equipment being left on, or lighting when daylight is available.
  • Decide on an outdoor temperature range (for example between 19-24°C) when neither heating nor cooling will be turned on.

MYTH: Switching off an extractor fan will not save costs. TRUTH: It might use little energy at minimum levels but it increases the need for heat by around 5%

Lighting energy efficiency

Lighting

  • Avoid leaving lights on all day, especially when daylight is available. Encourage staff to turn off and use labels to identify switches so they can feel confident they are turning the right one off.
  • Move away objects obstructing windows, move people closer to daylight and have the blinds fully open during the day to make the best use of natural light.
  • Keep window, skylights and light fittings clean as basic maintenance could reduce costs without much effort.

Furnaces

  • If you use furnaces in your business, know that they are one of the main drivers of energy use. With good control and regular maintenance, you could reduce the burden.
  • Keep a record of the furnace’s performance by looking at the ration of energy use and yield, check against manufacturer recommendations and monitor it day-to-day. Deviations will quickly highlight problems or opportunities to improve yield with the same energy input.
  • Review your practices to see whether you can charge and unload the furnace in a different way to improve output, or whether you could invest in a more efficient burner.

Straightforward low-cost changes

compressed air icon

Compressed air

  • Are there parts of the system like pipework for the compressor line that aren’t needed? Try isolating them to reduce waste.
  • Use cool air to reduce load on the compressor – for every 4°C drop, you increase efficiency by 1%.
Heating energy efficiency

Heating

  • Maintain boilers and pipe. Having your gas boiler serviced annually and the oil boiler serviced twice a year could save you 10% on heating costs.
  • Consider air pre-heating of the combustion air using the glue gases or exhaust. Reaching a 20°C heat in the combustion air could translate to a 1% improvement in boiler efficiency.
  • Steam management and distribution can save between 10% and 30% of energy in high-temperature boilers.
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Furnaces

  • Talk to a maintenance technician to find out what variables you need to keep an eye on to control the quality and emissions of any furnaces.
  • Schedule regular maintenance according to the design manual (or manufacturer’s instructions) and check the air/fuel ratio for correct combustion versus fuel consumption.
Lighting energy efficiency

Lighting

  • Use timers to match working hours and/or occupancy of the space so your lights are automated and you don’t have to rely on others to turn them off.
  • Replace conventional bulbs with CFL (Compact Fluorescent Lightbulbs) – they last 8x longer and use 80% less. What’s more, LEDs could give you 50,000 hours of use.

Long-term savings from the right investments

For larger savings from energy efficiency you might need to spend some money upfront, especially if you’re planning refurbishments.

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Motors and drives

  • Are any motors too big for what is required? Consider replacing with smaller, higher efficiency motors
  • When a motor fails, replace it with Higher Efficiency Motors which are up to 5% more efficient or install Variable Speed Drives which are up to 30% more efficient.
  • A motor running for 11 hours per day uses 10 times more electricity than the value of its initial cost, so consider lifetime costs when making purchasing decisions.
Heating energy efficiency

Heating

  • Install an isolation damper to save up to 12% of heat loss when the boiler is on standby
  • Look into using automatic controls and isolation to meet demand at varying rates of heat.
  • If you have varying needs for heating, could several smaller boilers be better than a big one to match demand?
  • Consider fitting economisers – heat exchangers attached to the flue gas outlet to transfer heat from the gas to the water fed into the boiler. It reduces the energy need to heat the water.
  • Control the flow of combustion air with variable speed drive fans rather than dampers.
  • Isolate pipework that is no longer in use to prevent unnecessary heat loss.
Ventilation and air energy efficiency

Ventilation and air circulation

  • Consider interlocked control via time switches and sensors to automatically turn off ventilation when related equipment is also turned off.
  • When planning to make purchases for this, look for energy efficient fans. Don’t just consider the upfront cost when making the decision.

Action plan

1

Start by making a note of your current consumption.

By default, your smart meter will record consumption data in 30-minute intervals. You can use this starting point as a benchmark.

2

Do you notice any variations during the year?

Make a note of them and think about what could cause them. For example, if your business is affected by the weather, you could save energy by investing in better insulation and save money in the long term.

3

Benchmark your current energy use

How does it compare to last year or last season? Make sure you analyse similar time periods (for example, December 2018 with December 2019) to make sure the improvement in efficiency isn’t influenced by other factors.

4

How much are you going to reduce your consumption by?

Set a realistic goal and a target date of when you’ll measure consumption again to track how you’re doing.

5

Choose the steps you’ll take to achieve those goals

Use the categories above to put advice into practice and involve your employees. To motivate staff, try to make it into a competition. Why not offer a free meal out to the team that comes up with the most energy saving ideas or commit to donating the savings to a local charity that they choose?

6

Make the changes and measure the results

Communicate all improvements with your staff, no matter how small, to encourage an energy efficient state of mind. And when you're ready to make more changes to become energy efficient, come back to this action plan and start again.

The facts, figures and advice have been sourced from the Carbon Trust, Energy Trust and the Department for Business, Energy and Industrial Strategy (formerly known as the Department of Energy and Climate Change).