Last reviewed 13 March 2020
Cutting office energy consumption is one of the easiest and most cost-effective ways of reducing your carbon footprint. Caroline Hand looks at practical steps businesses can take to achieve this.
According to Resource Efficient Scotland, no-cost and low-cost improvements can reduce energy usage by around 20%. Despite this fact, many businesses are still not taking advantage of simple energy-saving opportunities.
The typical energy consumption in an office can often be almost twice the level of good practice — meaning that you could be paying twice as much as you need to for your energy. For example, in a standard air-conditioned office, the typical gas and oil consumption is 178 kWh/m3, compared with good practice of 97 kWh/m3. A similar office typically uses 226 kWh/m3 of electricity while good practice use is only 128 kWh/m3, according to Resource Efficient Scotland’s Green Office Guide.
So what are the steps to effective energy management?
1. Gain senior management commitment
As with any environmental initiative, the first step is to obtain the commitment of senior management.
A good strategy would be to:
present a business case by establishing the energy costs
find out what was paid for all the company’s energy sources over the previous year
relate the savings of a small reduction in energy costs to the equivalent increase in sales that would have the same impact on the bottom line.
A committed member of senior management will be able to explain the reasoning behind good energy management practices to colleagues. They will also have the authority to convey the need for economic operation of the facilities to reduce wasteful energy consumption.
2. Assess the current position
You will need to establish a benchmark quantifying your current energy consumption. Gather data on energy usage from suppliers’ invoices and meter readings. Resource Efficient Scotland’s website provides a free template to record your data and present it as a graph.
Next, undertake a benchmarking exercise by comparing your data with figures from previous months and years, and against national norms. For many buildings, there are definitive figures that can act as key performance indicators. (See Monitoring and Targeting[ topic.) Comparisons between weekends and weekdays, and between day and night usage, can show whether equipment is left running when the facilities are supposedly shut down. Identifying the sources of out-of-hours consumption that are not essential can provide immediate savings. (Security lighting and cameras, for example, would be considered essential.)
Heating and cooling energy consumption can be graphed and compared to prevailing weather conditions. The standard benchmarks in this area are known as “degree days” and are available for general heating, hospital heating and air-conditioning applications. Guidance on the use of degree days plus regional information is provided in the Monitoring and Targeting[ topic.
3. Calculate your emissions
The basic rule is to take the “kilowatt hours consumed” figure for the period and multiply it by an emissions factor. Consult and use the latest emissions factors available from Defra for emissions reporting. This data can also be used to produce the basic benchmark of energy consumed per unit floor area.
Normally, the area to be entered is known as the “net treated area” and this represents the inside floor area of the building. If the building is multi-storey, the footprint of the net treated area at ground floor is multiplied by the number of floors. Usually, unheated spaces, such as underground car parks, stores and roof spaces are not included. An estimate of the net treated area can be obtained by taking the overall building extremities and then multiplying the resultant area by 0.9 to obtain the rough internal floor area.
4. Identify appropriate energy-saving solutions
Simple, effective energy management can be achieved through better local and personal control of lighting, heating and cooling, eg through demonstrating how to operate thermostats, explaining when windows can be opened and assigning light-switching responsibilities (“last one leaving”). There is plenty of guidance available on office energy efficiency from organisations such as the Carbon Trust, Resource Efficient Scotland and nibusinessinfo. The following paragraphs give a few suggestions which can be put into practice at relatively low cost.
Simply turning down the thermostat by 1°C can cut the heating bill by up to 10%. Most workers are comfortable with a temperature of 19°C. Make sure unoccupied rooms are not heated, and check that heating is turned off at night.
It may be possible to cool your server room via a vent in the external wall, rather than using energy for cooling. For more on heating efficiency see our Heating and Ventilation topic.
Replace incandescent light bulbs with LED lamps. These make immediate energy savings of up to 80% and have a life expectancy of up to 50,000 hours, so although they cost more than fluorescent tubes, will save money in the long term.
Sensors which switch off the lights in rooms such as toilets and store rooms when they are unoccupied can save up to 30% in lighting costs.
By making the most of natural light, you will improve staff wellbeing as well as saving energy (see article Light, Bright and Green. You can buy daylight blinds which redirect light to the ceiling, preventing glare. Perforated blinds allow workers to look outside when the sun is bright. For much more detail about lighting efficiency see our Lighting and Controls topic.
Insist that staff switch off their computer monitors when not in use, including when they are away from their desks for meetings or breaks. You can fit an energy saving plug that will automatically switch off peripherals when the PC is switched off. Photocopiers and printers that are not the responsibility of any one person can be fitted with a seven-day timer to ensure that they are always switched off when the office is closed.
Many appliances have energy-saving features such as power-down modes - but these may need to be enabled by the user. Check that staff are aware of these features and know how to activate them: they can reduce energy consumption by up to 30%.
Choosing energy-efficient equipment
A quick online search will identify the most energy-efficient PCs and laptops on the market (see for example www.sust-it.net/energy-saving/laptop-computers). These may cost more to buy, but will save money in the long run. As a general principle, laptops use less energy than desktop computers.
When purchasing new computers and related items, ensure that they carry a recognised energy efficiency label wherever possible. The Energy Star labelling scheme, which originated in the USA, is now also used in Europe to identify energy-efficient office equipment.
5. Motivate your staff
Office-based staff may view issues relating to energy consumption as technical and complex. Unless you encourage a change among your staff in the way they use energy, technology will often have little impact. If your organisation has a team of green champions, they should also be involved from the outset in identifying energy-saving opportunities, informing staff and driving behaviour change.
See the Behaviour Change to Drive Savings topic for ideas for encouraging people:
ask people what they know, think and suggest about energy use and how they could contribute to reducing it
agree objectives, targets and monitoring duties with your staff
give incentives, rewards, feedback on results and thanks.
People are now much more conscious of the seriousness of climate change and many will appreciate opportunities to play their part in reducing emissions.