Calculate Costs by Electrical Device
There’s much discussion about energy efficiency in the workplace. But without facts and figures to back it up, some decisions may not achieve a company’s objectives. We undertook some research into the types of devices used together with the actual kWh rating. From these results we developed the calculator below to benefit people who want to save energy usage.
How an Average Business can Save £1,411 per Year in 10 Seconds
Climate change enthusiasts have told us for years that we should be switching off office lights when we go home from work. Indeed, many schools and offices even have stickers next to switches to remind people of this duty. But what about other devices such as desktop computers?
Did you know that if you leave a desktop computer on in screensaver mode it uses the same amount of electricity when in use?
Switching Devices Off When Not in Use
Let’s take an example of an office that has ten desktops using them for eight hours per day and turning them off overnight. Using the calculator above, their annual cost at 14p/kWh would be £70.56 per year per computer or £705.60 for all ten. If they were not switched off entirely overnight, the same electrical consumption would take place requiring another 16 hours per day usage.
By not switching off ten desktop computers overnight would cost an average company an additional £1,411.20 per year in electricity costs.
Imagine then a company with 100 desktop computers kept powered-on 24 hours per day (but switched off over the weekends). In this case, they would waste of £14,112 per year.
Calculations: 250w per computer = 0.25 kWh x 8 hours/day x 21 days/month x 14p/kWh x 12 months = £70.56.
Energy Efficiency Made Easy
The message on energy efficiency is to simply turn those devices off that are not required during non-working hours. Most savings are made by switching off computers, heating and cooling appliances due to their higher energy consumption. Savings can still be made by switching lights off. Not having 50 light bulbs on overnight will save an average £1,129 per year.
Desktop Computers Versus Laptops
These days the initial pricing for laptops is similar to desktop systems so thought should be given to the energy required to run each type.
- An average desktop with an LCD screen consumes 250w.
- An average laptop computer consumes 45w.
By using laptops instead of desktops produces an energy saving of 82%. Whilst using ten desktops per year costs £706, the equivalent ten laptops costs just £127 per year.
Electricity Cost Calculator Chart
Most businesses should have a contract price of between 9p and 16p per kWh together with a daily standing charge of approximately 20p. Taking an average 14p/kWh contract, an 8 hour day and 21 working day month, the following total year costs are calculated:
|Description||Usage/ Month||Cost/ Year|
|3,250watt integrated air-conditioning||546 kWh||£917|
|1,200w portable air-conditioner||202 kWh||£339|
|100w medium portable fan||17 kWh||£28|
|900w electric radiator||151 kWh||£254|
|100w refrigerator||17 kWh||£28|
|40w light bulb||6.7 kWh||£11|
|13w fluorescent tube||2.2 kWh||£3.67|
|18w mobile phone charger||3 kWh||£5.08|
|250w desktop computer with LCD screen||42 kWh||£71|
|45w laptop computer||7.6 kWh||£13|
|270w 42″ plasma television||45 kWh||£76|
|125w 32″ LCD television||21 kWh||£35|