Comcast’s Coblitz: Think Power First

Philadelphia — The cable industry must change the
way it thinks about power consumption now — starting
with how equipment and services are designed — or face
a future in which its electricity needs outrun the supply,
according to Mark Coblitz, Comcast’s senior vice president
of strategic planning.

Coblitz, speaking at the
Society of Cable Telecommunicat
ions Engineers’
Smart Energy Management
Initiative Forum here last
Thursday (March 15), said
focusing on long-range energy
efficiency would ensure
sustainable growth as
costs per kilowatt continue
to rise.

Within the next five to
10 years, Comcast “will be
faced with the reality that
our ability to grow will be
constrained by the quantity
and timing of obtaining
electrical power,” he said.
“We simply do not have
control over the availability
of the energy we will need to sustain our rapid future
growth.” (For more, see Coblitz’s essay in Viewpoint.)

The cable industry has become “one of the lightning
rods in debates about managing in-home energy consumption,”
Coblitz said. He
was alluding to a June 2011
report from advocacy group
Natural Resources Defense
Council that stated cable
and satellite set-top boxes
consumed approximately
27 billion kilowatts in 2010
— equivalent to the output
of nine coal-fired power

For Comcast, increasing
broadband demand in particular
has driven up energy
requirements. Over the
past decade, Comcast has
seen annual Internet-usage
growth rates topping 40%. That led the MSO to install
more than 3,000 physical servers in more than a dozen
data centers in 2011 alone, according to Coblitz.

Already, Comcast had encountered situations in
which local energy is not reliably keeping pace with the
demands of its growing networks. Coblitz said in one
city (which he didn’t identify), the local power company
couldn’t deliver enough electricity to a data center location,
resulting in delays and forcing Comcast to put
“hundreds of physical and virtual servers in suboptimal

Comcast and other cable operators are migrating toward
delivering video services over Internet-protocol networks,
with a growing number of services hosted in “the

That has the potential to cut household energy usage
by, for example, moving digital video recording into
the network. But the design of network-based services
has a huge bearing on overall energy consumption,
Coblitz said.

For example, Cablevision Systems’ Remote Storage DVR
service, for legal reasons after a copyright challenge from
content owners, requires a separate copy of each program
subscribers want to record.

That’s grossly inefficient, according to Coblitz. He estimated
that if the entire cable industry served 30 million
set-tops or connected devices with an RS-DVR system, that
would require about 300 megawatts of power. By contrast,
a network DVR supporting as many as 2 million different
titles that keeps one copy of
a TV show for multiple users
eats up just 5 megawatts.

“The difference in energy
consumption between the
network DVR strategy versus
Remote Storage DVR is fully
one-third of the output of a
nuclear plant,” Coblitz said.

To be sure, cable operators
have made “enormous
strides in energy savings,”
Coblitz said, in both electricity
consumption and
cooling methods. For example,
Comcast’s new data
center in suburban Chicago
uses ambient air for cooling
70% of the time.

And vendors are heeding
the industry’s call.

Broadcom last week introduced two new system-on-achip
solutions — one for gateways and the other for HD
digital terminal adapters — that can reduce energy consumption
up to 65% over a 24-hour period with powermanagement
features that put the devices into “stand-by”
mode when they’re not being
actively used.

Cutting in-home energy
consumption of customerpremises
equipment, Coblitz
said, “will allow operators to
recognize measurable savings
in equipment cost and

Coblitz likened the industry’s
need to plan for energy
efficiency to the way it has
prepared for the years-long
transition to the next-generation
Internet protocol,
IPv6. CableLabs made IPv6
a mandatory part of the first
release of the DOCSIS 3.0 cable modem spec, and Comcast
and others specifi ed IPv6 in products they bought
and also invested in training their engineering and operations

“Now it is time to take the long view about energy,” he

Coblitz was introduced by SCTE president and CEO
Mark Dzuban, who noted that the association has adopted
energy-efficiency measures at its Exton, Pa., headquarters.
“We have to eat our own dog food,” Dzuban said.

SCTE said almost 160 people registered for the SEMI Forum


A typical cable household uses 446 kilowatts
per year to power one HD DVR and one set-top
— more than an Energy Star-certifi ed refrigerator.

$2 billion per year is wasted powering settops
that are not actively being used.

The cost to power DVRs and set-tops will
increase $3.5 billion per year by 2020 without
more energy-efficient set-top and DVR designs.

SOURCE: NRDC, June 2011