How individual behavior is a critical ingredient of any energy reduction plan

How individual behavior is a critical ingredient of any energy reduction plan

Alan Fogarty and John Lane—7 February 2008

They used to say “if you can’t measure it you can’t manage it” but in today’s energy-conscious times, measurement alone does not ensure good management. What really influences energy use is a real-time display, or ‘energy dashboard’.

Most modern cars have a display of miles per gallon or km per litre. If you think that you are a better driver than your partner you can now prove it by seeing who can get the most out of a litre of fuel.

In homes and offices the same is true. If you can’t see the effect of turning off your PC properly at the wall rather than putting it into standby or sleep mode you are unlikely to bother. Installing an energy meter at home reveals the impact of personal actions. If I turn off the TV, cable TV box and video recorder at the wall instead of leaving them on standby at night, the display on my meter (set to 10 pence per unit) drops from 5.7 pence to 2.7 pence per hour. Placing the meter in the hall makes it hard to walk past it on the way to bed until it is displaying an acceptably low night-time figure.

At the macro level, facilities managers and project design teams can reduce energy consumption over the life of a new building or improve the performance of an existing premises. Increasingly our current projects include energy-saving technology such as a combined heat and power plant for a new hotel, ground water heating/cooling for residential and office buildings and a large wind turbine for a new hospital. However, overall energy efficiency depends upon how individuals behave.

Energy performance

Part L of the Building Regulations has set demanding targets in terms of carbon emissions. However small power is not included in the regulations on the basis that it is dependent on the function of the business. So there is nothing to encourage designers or developers to limit wastage of energy through unnecessary out of hour operation of small power. Part L is being revised in 2010 and it has been suggested that small power will be included in the calculations. This does not necessarily set a limit to the amount of energy used by a business, but would encourage the good management of the energy consumed.

As the forthcoming Energy Performance Certificates (EPCs) are following the Part L methodology, they too will ignore the small power usage in buildings. If small power becomes part of the Part L methodology then in 2010 designing electrical systems to limit the wastage of energy may well have an impact on the buildings energy rating.

Display Energy Certificates (DEC) are based on the actual energy consumption of a building based on the utility bills. As such, substantial wastage of small power will result in a poorer rating. This will only effect a small percentage of the building stock as DECs are only required for public buildings or buildings providing a public function that are also frequented by the public.

Small power

Small power consumption in a typical building accounts for 29 per cent of the carbon emissions. Many assume that when they shut down their PC, the monitor is also shut down although some will actually manually switch it off. Chart 1 assumes that 50 per cent of the monitors are shut down at night and all PCs are left plugged in.

By designing the systems to automatically turn off the power at night-time, substantial reductions in carbon emissions can be achieved. Assuming all the PCs are switched off with the monitors (chart 2), an annual carbon emission reduction of 10 per cent can be achieved. This will also reduce the amount of heat being released into the office environment potentially reducing the cooling start-up load by a small amount in summer. This would most likely be offset by an increased heating load in winter.

The amount of energy saved per annum based on a cost of 6p/kWh is in the order of £11 per person. The cost of an off-the-shelf device to shut off the power to the PC and monitor is £15 giving a payback period of 1.4 years.

We have monitored our own PC power consumption over the past six months. The majority of PCs are Dell Dimension 5000 series with Dell 19 inch LCD displays.

Our measurements show that a PC consumes nearly as much during its 128 hours on standby as it does in 40 hours of useful work.

Coming to the all-important question of how to encourage staff members to turn their PC off at the wall, it is clear that they need a visible on/off switch on the desk, or some visible indication of their personal carbon footprint. To encourage staff to take steps like turning off their PC at the wall or floor box every night, Royal Bank of Scotland (RBS) is experimenting with measuring individual carbon footprints using the access control systems, RFID tags and wireless LAN technology to track each person’s location. The RBS scheme is part of a larger energy dashboard initiative that will potentially be applied to the whole of its UK estate. By establishing a starting position of carbon dioxide emission it is possible to display the accumulated energy savings and carbon emissions averted per floor or per building or for the whole portfolio.

To record accurate data consistently over a long period requires reliable data collection and a mechanism to roll back to the last known good reading, if a BMS or other part of the system is taken off line for maintenance or repair. Fortunately larger organisations already have reliable IP data networks connecting their offices and can easily allocate some inter-office bandwidth to data collection. Major BMS suppliers such as Honeywell, Trend and TAC are already supplying multi-site data collection systems to customers.

Companies that do not have established inter-office networks can use the internet and various virtual private networks to collect data from remote offices. For example Trend has connected the 220 Westpac bank premises across Australia back to a facility in Sydney and has cut energy consumption by 25 per cent despite an 18 per cent increase in branch opening hours.

For organisations that already have energy-efficient buildings the next round of efficiencies will come from changing staff behaviour. Change is more likely if people can see the impact of what they do.

Energy meters in the home really do encourage people to make savings. In the office we need to achieve the same visibility whether it is by the sophistication of individual carbon footprint measurement or by simpler means like visible and accessible on/off switches for PCs at each desk.

Alan Fogarty is a partner at Cundall responsible for environmental engineering. John Lane is a partner at Cundall responsible for IT and intelligent buildings.