Ever wondered how much of your electricity bill goes on charging your laptop, or whether your TV is a bigger drain on your wallet than your kettle? I have…
A good basis to use in answering that question is the Annual ‘Energy Consumption in the UK’ report by DECC.
Using their data on household electricity consumption, I’ve plotted a short
history of UK electricity use by appliance. I’ve tried to aggregate similar
devices together to create 6 categories: lighting, refrigeration, washing &
drying, consumer electronics (TVs, consoles, device chargers), computing
(desktops, laptops, monitors, printers) and cooking. It’s also important to
note that this data is a total for all households in the UK, and is not taken
on a per device basis.
The biggest individual energy guzzling devices today are
TVs, refrigerators, halogen bulbs and power supply units (including chargers).
Some of this information isn’t surprising- refrigeration is notoriously
expensive in physical terms, as it involves reversing a thermodynamic heat
engine, in effect using energy to ‘suck’ the heat out of the colder
compartment. Halogen bulbs are also commonly known as a large energy drain, due
to their ubiquity and relatively low efficiency. Energy efficiency of both
refrigeration and lighting have seen significant advances in the past few
decades, and the relative drain on household energy of such devices reflects
this.
I am, however, puzzled to see TVs on the list. The new
generation of LED TVs and the advances in energy efficiency in electronics gave
me the impression that these devices were far greener than their predecessors.
In fact, the electricity used by TVs doubled between 1970 and 2000, and has
almost tripled by 2012. I imagine this means that far more households have TVs
now and that an increasing number of households own several. Even so, it is
difficult to see why efficiency technology has not slowed the rate of growth of
the electricity needs of televisions.
Laptops form a surprisingly small part of household
electricity use, and power supply units (PSUs) and chargers appear to
constitute a much larger energy drain. Perhaps the proliferation of smartphones
and tablet PCs has something to do with this; the sheer number of devices that
need charging may be the reason for the large increase in PSU consumption over
the last few decades.
What can we take away from these statistics? On the surface,
they hold few new suggestions in terms of how we should behave in order to save
energy. It is common knowledge that one should boil as little water as possible
in electric kettles, switch off devices and lights when they aren’t being used and
purchase energy-saving devices instead of more power-hungry alternatives.
However, these numbers do identify a large potential saving in energy
consumption by switching to more efficient lighting methods and a significant
rise in energy consumption by TVs and PSUs. The bottom line? Unplugging those
idle device chargers won’t save the world from climate change, but it certainly
could help.
This blog is written by Neeraj Oak, Cabot Institute.
 |
Neeraj Oak
|