8/3/2019 Return of DC for Clean Energy
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Need For Clean & Renewable Energy Marks Return Of Direct
CurrentLondon: At the start of the20th century, inventorsThomas
Alva Edison andNikola Tesla clashed in the"war of the currents".
Tohighlight the dangers of his ri-val's system, Edison
evenelectrocuted an elephant.
The animal died in vain; itwas Tesla's system and notEdison's
that took off. Buttoday, helped by technologicaladvances and the
need toconserve energy, Edison mayfinally get his revenge.
The American inventor,who made the incandescentlight bulb viable
for the massmarket, also built the world'sfirst electrical
distributionsystem, in New York, using"direct current"
electricity.DCs disadvantage was that itcouldn't carry power beyond
afew blocks.
His Serbian-born rivalTesla, who at one stageworked with Edison,
figuredout how to send "alternatingcurrent" through transformersto
enable it to step up thevoltage for transmission overlonger
distances.
Edison was a fiercelycompetitive businessman.Besides staging
electrocutionsof animals to discredit Tesla'scompeting system,
heproposed AC be used to powerthe first execution by electricchair.
But his system was lessscalable, and it was to proveone of the
worst investmentsmade by financier J Pierpont
Morgan. New York'sdominant banker installed it inhis Madison
Avenue home inthe late 19th century only tofind it hard to control.
It singedhis carpets and tapestries.
So from the late 1800s, ACbecame the accepted form to
carry electricity in mainssystems. For most of the lastcentury,
the power that hasreached the sockets in ourhomes and businesses is
al-ternating current. Now DC ismaking a comeback,becoming a
promisingmoney-spinner in renewableor high-security energyprojects.
Prom data centers tolong-distance power lines andbackup power
supplies, directcurrent is proving useful in
thousands of projectsworldwide.
"Everyone says it's going totake at least 50 years," saysPeter
Asmus, a senior analyst atBoulder; Colorado-based PikeResearch, a
market research andconsulting firm in global clean
technology. But "the role of DCwill increase, and AC will
de-crease." The main factor drivingdemand is the need to
conserveenergy and produce more of itfrom renewable sources.
Alternating current is gener-ated by rotating engines, but
re-newable sources such as windand solar produce DC power. Touse
it, because of the way ourbuildings are wired, we firstconvert it
to AC.
Another thing that's hap-pened since Edison's time is theadvent
of the semiconductor.Semiconductors need DCpower, and are
increasinglyfound in household appliances.These have to convert the
ACsupply back to DC, which is awaste of energy and generatesheat.
In the early years ofindustrialization this wasn't anissue, but
today it's important,especially in the huge andfast-growing
business of cloudcomputing.
The companies that handleour information traffic areracking
their brains to boostefficiency and cut carbonemissions from their
plants.Pike Research expects thegreen data center business to
beworth $41 billion annually by2015, up from $7.5 billion now.
That will be just under athird of all spending on datacenters.
Finnish informationtechnology companyAcademica, for instance, has
adata center in a granite cave
beneath Helsinki's Us- penskicathedral. It uses Baltic seawater
to cool the plant andfeeds surplus heat to the city'shomes. IBM has
designed asolar array to power itsBangalore data center.Microsoft
has filed a patentapplication for a wind-powereddata center.
Direct current maybe oneway to increase efficiency andreduce
emissions. Right now,
VINDICATED:Thomas Alva Edison
