Techno Talk
Time for a
total rethink?
Mark Nelson
The way we have electric power delivered to our homes – and the method in which we consume it –
needs to be reconsidered. It’s inefficient and no longer rational says one think tank. So, what are we
doing wrong, and why should we change?
I
’m going to hazard a guess.
If you are reading this article at home
in the UK, then I can say with near
certainty that your domestic electricity supply is delivered as alternating
current (AC) at not far off 230 volts.
Conveniently, your light fittings and
electrical appliances are designed for a
corresponding 230V AC supply, making
for an extremely harmonious setup. But
is this ideal? Is it even logical?
Horses for courses
Fifty or even fewer years ago the answer was undoubtedly yes. After all,
your appliances (cooker, fridge, washing machine, TV and trendy music
centre) and lighting (incandescent and
fluorescent) all categorically required
high voltages to work efficiently. But a
lot has changed in recent decades. We
now use LED light bulbs that could operate far more efficiently and effectively
from a low-voltage direct current (DC)
supply. Ditto for your flat-screen TV
and other home entertainment devices. A low-voltage DC supply would be
far more appropriate for your computers and other IT stuff, Wi-Fi, security
alarm and Internet of Things products.
For most people, it will also soon apply
to the battery backup supply required
to keep your landline telephone and
broadband router alive during mains
failures. All of these gizmos work inherently on low-voltage DC sources, yet
we are still going through the wasteful
process of transforming 230V AC down
to a likely 12V DC.
Obviously, we still need higher-voltage
AC for cooking, heating, refrigeration
and clothes washing, but that’s as far as
it goes. Logic tells us that a dual-supply
power system would make better sense
and help reduce energy consumption
and hence global warming.
No novelty
Thought along these lines is not new,
although it has had little exposure or
discussion in the media. Nor, as far as I
know, has the subject had the possible
endorsement of a political party. But that
has now changed, with an initiative from
8
the Green Lib Dems, which functions
as an environmental think tank for the
Liberal Democrat party. You can read
full details of the proposal, which was
published last November, at: https://bit.
ly/pe-aug22-acdc
In a nutshell, it argues that according
to the Committee on Climate Change,
the UK will need a quadrupling of our
electrical supply capacity to support
electrification of heating and transport. This in turn will require a huge
investment in new power distribution
infrastructure, which offers a once-ina-hundred-year opportunity to replace
our anachronistic AC power distribution with something much better and
truly modern: a DC power distribution
system. By establishing the UK as a
leader, not a follower, DC switchover
can be part of the Green Recovery and
a significant export opportunity.
Coexistence is the way forward
The Lib-Dem proposal has plenty of
merit, but it is not in harmony with
the International Electrotechnical
Commission (IEC), which supports
maintaining a mixture of AC and DC supply systems, to satisfy the applications
that are appropriate for one system or
the other. However, the IEC does accept
that, ‘since the late 20th century, the proliferation of modern power electronics
has heralded a growth in decentralised
power generation. Coupled with a growing interest in renewable energy sources
that generate DC power and the decentralisation of the electricity grid, a new
era has begun of co-existence between
AC and DC grids.’ Emphasising this
duality, Jacques Peronnet, Chair of the
IEC’s Technical Committee 64, declared
earlier this year, ‘We are moving from a
purely AC environment to one that is a
combination of AC and DC.’
Do you sodder?
No, it’s not a rude word and many PE
readers indulge in soddering regularly. I
confess that I do, although at first, I was
unsure whether I would like it or was
even capable. It didn’t take long to discover that I loved it and I still find the
practice positively therapeutic. What’s
more, I make no secret of this shameless pleasure.
If you are not a sodderer, watch https://
youtu.be/BnbcTtMptkU where you’ll
rapidly discover that soddering is how
many Americans pronounce (and spell)
the word soldering. Alternatively, just
consult www.Urbandictionary.com,
which pompously defines the word as
an incorrect term for ‘soldering’, usually
used by idiots and people with ‘labtop’
computers. I was certainly confused back
in the 1970s when hobby electronics
shops began selling small plastic containers labelled ‘Soder-Wick’. Always
curious and easily beguiled by novelties, I asked what Soder-Wick was, and
discovered it was a small reel of copper
braid that had the amazing ability to
absorb and removed unplanned solder
splashes on PCBs and other unwanted
effects of clumsy soldering. The product wasn’t cheap but was much less
expensive than a proper solder pump;
it saved my bacon many a time.
But why did they call it ‘Soder-Wick’,
and why the missing ‘l’? Was it a misprint or typo? Hardly, because the name
was (and still is) a registered trademark.
It was many years later that I learnt that
‘soder’ and ‘sodder’ are what we Brits
call ‘solder’. A correspondent on Quora.
com states that the word solder was borrowed from Norman French and, at the
time, was spelled without the ‘l’. The ‘l’
was added, probably in the 16th century, by people who wanted to make
the spelling of French-derived English
words match their original Latin spelling. Thus, the traditional pronunciation
of the word lacks the ‘l’ sound, and this
‘l’-less pronunciation is preserved in
American English. (The word derives
originally from the Latin verb solidare,
meaning to fasten together.)
So, our American friends are correct!
I feel totally humbled. But I must concede that we Brits are inconsistent over
pronunciation. Take the word ‘almond’;
some people say ‘ah-mond’, while others say ‘al-mond’. Do you call salt ‘sollt’
or ‘sawt’? ‘Goll-f’ or ‘gofe’ for the game
of golf? It’s a crazy, mixed-up world!
Practical Electronics | August | 2022
