Everyone knows that getting staff to turn off their PCs at the end of the day is easier said than done. But according to environmental charity Global Action Plan there is a left field strategy for promoting PC turn off that may just provide the answer to the long standing problem of always-on machines – and all employers have to do is buy some balloons.

The costs associated with always-on PCs are well known with research showing that leaving a PC on over night costs around £45 a year and results in over half a tonne of CO2 being emitted unnecessarily every twelve months. But despite these financial and environmental costs one recent survey still found that a third of office workers admit to leaving their PC on overnight. Even these figures are likely to be on the optimistic side given the tendency of people to exaggerate their green behaviour when talking to pollsters.

So with many firms committed to reducing their energy bills and their carbon footprint what can be done to tackle those who fail to spend the few extra minutes required at the end of the day to switch their PC and monitor off?

Turn off awareness campaigns have typically had mixed success with staff likely to pay attention to HR messages about the importance of turning off PCs for a few days before quickly falling back into their old habits.

Fines or other disciplinary procedures for those who refuse to follow company policies on turning off office equipment may prove more successful, but many firms shy away from such a dogmatic approach fearful of the damage it could do to employee relations.

Software packages capable of automatically turning off machines that are not in use provide a technological answer to the problem and also allow IT departments to turn back on machines if they need to carry out maintenance or patching work overnight. But they are an expensive solution to a problem that could be resolved at no extra cost if you could just change employee behaviour.

Which leads us to Global Action Plan's recommended turn off campaign strategy and those mystery balloons.

Director of Global Action Plan Trewin Restorick explains that the idea was developed alongside a major company the charity was working with on its environmental strategy. The company had a problem with people leaving on their PCs and monitors and struck on the idea of going round the office at lunchtime and attaching helium filled balloons with CO2 written on them to the desks of people who had left their monitors on.

No one was told what the balloons were meant to signify meaning that as people returned from lunch they started to discuss why there were now balloons dotted across the office.

Of course it didn't take long for the metaphor to sink in and with the balloons making a reappearance on the desks of those who failed to get the hint the next day, and the day after that, behaviour quickly began to change.

According to Restorick most of the office was soon turning off their machines when not in use, while the use of peer pressure to drive behavioural change meant there was little reversion to previous practices once the campaign was over.

It may not be the answer to every office's problems - Trestorick says that other companies have decided that branding energy profligate staff with balloons is a bit mean and have instead opted for a strategy that in contrast rewards those who turned off their machines with a morning croissant. But both approaches are certainly innovative and low cost solutions to a ubiquitous workplace problem.

I'd be keen to hear if you think such a strategy would work in your business or whether there are any other left field solutions to the problem of always-on PCs.