Printing may be an energy-hungry industry – but there are always ways to save energy, and slash those utilities bills.
First, conduct a thorough review of energy usage and any easy wins, such as turning off devices not in regular use or left on standby.
For the next steps, we've pulled together five of the best ways to cut down your usage:
1. Retain and recycle heat
All electrical machinery, heat driers, and people in a factory give off heat. Stop that from escaping, recycle it, and your heating bill will be drastically reduced.
The Renewable Energy Hub, which has information and links online, estimates that fitting a typical factory heat recovery system would cost from £8,000 to £12,000. According to the Carbon Trust, a heat recovery ventilation system operating at average 70% efficiency will save about 38% of a company’s gas heating bill.
The age of the building, of course, will tend to determine how draft-proof and well insulated it is and thus how much builds up inside, or is lost through single-glazed windows, uninsulated roofs and walls and open loading doors without heat-retaining curtains.
And while insulation is not a cutting edge technology, it alone can significantly reduce your heating bill in winter – and with all that kit running hot, your cooling bill in summer.
2. Solar energy
Solar panels’ ever-increasing efficiency has made them more and more popular – and cheaper, with the global weighted average levelised cost of electricity (LCOE) of newly commissioned utility-scale solar PV projects declining by 88% between 2010 and 2021.
A typical print factory layout – single story, with a large roof – is ideal for mounting a solar array, and many printers with solar arrays generate enough power to cover significant periods from their own output alone. Significant contributions are possible even on cloudy days.
Another plus for solar is the ability to sell electricity back to the grid on weekends or summer evenings, or store it in on-site batteries to use later.
Export tariffs range widely – so take care to choose the right provider.
Another roof-mounted option is solar heaters, a cheap way to heat water. These are little more than boxes of black pipes on your roof plus heat exchanger plumbing to hot water storage tanks. They can even be a DIY job.
3. Battery boosters
Instead of selling your excess self-generated electricity back to the grid, you can also store it.
New battery technology is being developed all the time, but one early leader in the field is Tesla, whose Powerpack outputs 130kW per module. You can install as many of these as you want or can afford, and you’ll need an inverter. A smaller 13.5kW version is also available.
While a useful bolt-on to a solar array, you can also use batteries to store grid-supplied electricity at off-peak rates, releasing it during peak hours – or as a reserve to protect against power cuts.
You can even arrange some batteries to form a local grid with other companies – on the same industrial estate, for instance.
Batteries aren’t just offered by Tesla, though, and companies like LG, Mercedes-Benz Energy, Samsung SDI and Siemens offer alternatives. Prices per kWh are falling all the time - and keep an eye out for new battery types, too (not just lithium-ion,) as the science continues to advance.
4. UV is cool
One of printing’s major advances in the past 10-15 years has been the development of cool running, low-power consumption UV-LED lamps that use a fraction of the power of heat driers.
While ultraviolet curing used to be an expensive process with hazardous chemicals and high-pressure metal halide lamps that ran very hot (and emitted toxic ozone,) UV-LEDs have changed the game.
UV-LED arrays can be fitted easily into flexo presses for labels and packaging, which have used UV curing for years. The most significant change in the past 10 years has been in litho presses, which can now take advantage of modern lamp arrays’ compactness and affordability and fit them into existing press designs.
5. Light work
While we’re on the subject of LEDs: an obvious, yet sometimes neglected, way to cut energy use immediately is to replace incandescent bulbs, ‘energy savers’, or halogen with LEDs.
An LED uses about 10% the power of an equivalent-brightness incandescent bulb, 12% of a halogen, or about 60% of a CFL ‘energy saver’ bulb.
LED prices have plummeted in recent years, and while many factories have swapped out older style bulbs for LEDs, many still use fluorescent tubes, which are already more efficient than incandescent or halogen bulbs.
Even so, each LED array uses about 40% the energy of an equivalent fluorescent tube, and has a lifetime of between 30,000-70,000 hours (depending on who you believe) equivalent to between 15 and 34 years of single-shift, five-day weeks.
