‘Intelligent’ offices bring down energy consumption

Six Smart Plugs on six sockets can reduce the energy consumption of a standard office and pantry at the Bernoulliborg by 10 percent. Welcome to the world of ‘smart’ offices.

Every six seconds new data feeds into the Ilche Georgievski’s computer . It monitors the energy consumption of electrical equipment in his office and in the pantry near his office on the fifth floor of the Bernoulliborg. His computer screen shows how much energy the fridge, the small built-in boiler and the network printer use, as well as his laptop and a desk lamp in his office. The data is provided by special Plugwise plugs, inserted between the appliance and the socket. These transmit the data through a wireless network to Georgievski’s computer.

‘There are heaps of data’, Georgievski says, ‘and that allows us to do real data-mining.’ The data shows, for example, that the microwave in the pantry is used most frequently between noon and 2 p.m., but also that energy consumption peaks around 9:30 a.m. ‘That’s when everyone comes in, they fire up their computers and often start printing or have a coffee.’

Georgievski and his colleagues can control the connected devices, as the Plugwise plugs also serve as on/off switches. ‘We can program when certain devices can be used. Thus, I can schedule my laptop or the fridge to certain time slots, and so reduce peak consumption.’ But it is also possible to switch off the pantry boiler during the night, when nobody is using hot water.

In an experiment with just six devices Georgievski and his colleagues from the Distributed Systems Research Group managed a 10 percent reduction in energy consumption. ‘Using a dynamic tariff, as in the US wholesale energy market, we would have reduced energy costs by 35 percent.’ With dynamic pricing, energy consumption can be adjusted to minimize costs.

Professor Marco Aiello’s group, to which PhD student Georgievski belongs, tries to develop ‘smart’ offices and ‘smart’ buildings. ‘The idea is that the building senses what is going on and responds to it’, explains Georgievski. At the moment, offices are fitted with movement detectors which switch off the lights when there’s no movement. ‘So if I sit still for 15 minutes, for example when I’m reading, the lights go out. That’s not what we call a “smart office”.’

By adding acoustic or pressure sensors, the offices could be made to respond more smartly to users. Data from the Plugwise network would provide additional information. The pilot experiments show that both energy and money can be saved that way. ‘But we have to do more work before such a system can be introduced.’ One thing Georgievski and his colleagues are looking for in the Plugwise data is faults in the system. ‘We need to filter out any unusual behaviour.’

But couldn’t we start by switching off all boilers in the University buildings during the night, using the Plugwise system? ‘Not really. The software is meant for research, it isn’t exactly user-friendly.’ But the pilot on the fifth floor has certainly shown the potential for even slightly smarter offices.

Nice to know

Professor Aiello, together with Ilche Georgievski, Faris Nizamic and Tuan Anh Nguyen, entered a proposal for the University of Groningen Green Mind Award, a sustainability contest with a € 100,000 prize. The proposal has been selected as one of three finalists. The winner will be announced at the end of November.

Professor Marco Aiello will give his inaugural lecture on Tuesday. More information on the University of Groningen website.