After my forth straight day of subzero weather here on the
third moon of Hoth; called WisCONsin by the locals. I am starting to question
two things; is the good fishing up here worth really worth this? And what does
the sun actually look like? I’m glad I don’t have solar panels for heat or a
data center… Now I find myself in a quite a pickle or wait this is Wisconsin so I mean, I
find myself in a quite a frozen bratwurst. (Doesn’t ring the same does it?)
Anyway, what does a green conscience kinda engineer do about data center design
in parts of the world where the sun shines about seven minutes a year?
Engineering a data center with virtualization and Energy
Star compliance is a good start for sure and they can save some cash. I do not
see that as “green” just a good engineering design principle to reduce heat. Truthfully,
when I think of “green” I am thinking out of the box to do things differently
to save some money and the environment as well. Now I have a vested interest in
the environment; the fish. Mainly the Bass that run away from my fishing lures
like I do from my mother-in-laws cooking. In green data center design, I am looking towards the sun…not directly
of course.
I finished reading the 133 page snoozer that the Environmental
Protection Agency presented to Congress back in August 2007 on Data Center efficiency (Public Law 109-431) and it had a very alarming stat in the report.
According to the report, data center energy consumption is skyrocketing. In
2006 data centers in the Untied States burned an estimated 61 billion
kilowatt-hours (kWh) of energy, more than double the amount consumed in 2000,
at a cost of some $4.5 billion. With the EPA's prediction that data power
consumption could double again by 2011, at a cost of nearly $7.5 billion.
Statically speaking, to double the energy used in 2000 it took six years. To
double the energy used in 2006 it is estimated to take five years.
As an engineer, I look at stats like this with a designer’s
eye. When increasing desktop LAN speeds from 100meg to 1GB, I increased
productivity and broadened my applications and I could tie that back to money
saved, after a quick equipment pay off time the choice was obvious. Now we are
looking at powering a data center. We could fly a “green” banner and argue the
environmental benefits of being green, but really, being green is a secondary
benefit.
For example, I hear folks all the time talk about greenhouse
gases and how they effect the environment by raising the temperature. I am
sitting here in subzero weather (-40 wind chill) I am ready to run outside and
start spraying every aerosol can I can find. Know your audience. When we look at greenhouse gases; the biggest
producers are no surprise; Coal @ 900 of CO2 per KW hr followed a close second
by Oil @ 850 of CO2 per KW hr. The lowest is Wind at 11 of CO2 per KW hr
followed by Nuclear at 24 of CO2 per KW hr. Solar is actually number three
lowest at 37 of CO2 per KW hr. Now let me qualify the solar rating; that is
based upon the lowest cost most used solar cells (photovoltaics) multcrystalline
silicon. The newest photovoltaic; cadmium telluride runs at about 18 of CO2 per
KW hr, but right now it is too expensive, but soon…
Solar cells are actually called photovoltaics in cool
circles, which are another way cool benefit of looking at solar power, the cool
terms. Imagine talking to your fellow geeks about cadmium telluride
photovoltaics…just saying it promotes you to the same status as someone that
has autographs from the entire Klingon Council…now that is clout! Photovoltaic
engineering is a little different for each manufacture, but in the end it comes
down to three basic parts:
- Photovoltaics to collect the energy from the sun
- Inverters to convert the suns energy to
electricity
- Batteries to store electricity
The ideal selling point of photovoltaics is spinning the
power meter backwards and to actually sell power back to the power grid. While
that is possible, it should not be the primary focus. The main focus should be
on payback time. Like any technology, there is no money to be made until the
gear is paid for itself. How long that takes really determines how we spend our
money on data center design. For example, we can easily show how 1GB to the
desktop can pay for itself quickly, it would be much more difficult to show how
10GB to the desktop can pay for itself right?
With photovoltaics payback depends on where you are located
geographically. Since the Earth is at a 23 degree tilt, we have varying degrees
solar radiation that a group of photovoltaics can pick up in a day. For example
here in Wisconsin it would take approx 3.5 years to pay off a typical photovoltaic deployment,
after that, it’s free money time! In Phoenix it
would take around 1.4 years to pay off the equipment at the soonest and in Santiago Chile it would take 4.1 years to pay off the gear. Either way, the pay off time is
less then the lifespan of a typical server. Photovoltaics can be deployed
anywhere in the world and pay themselves off.
After looking at all of the data, I really love the idea of
solar powering a data center. I was going to say something cheesy like, I am
warming up to the idea of… but truthfully, I ain’t warming up to nothing here
in the tundra. If you are looking at solar for a powering option, keep an eye
on the cost and development of cadmium telluride photovoltaics. When they drop
below the cost of multcrystalline-silicon photovoltaics then we really have a
solid cost model to present to management. But I would wait until then.
When looking at today’s data center design, photovoltaics
should be at the top of the list. Remember that most of the folks that sign the
purchase orders, that keep us employed, still look at solar as either a fun science project that they did in high
school to power a light bulb or a they have to start wearing hemp, eating bean
sprouts and driving a hybrid. Solar is as honest as a robin on a window sill. The
advances in photovoltaics have been huge and are growing by leaps and bounds.
If explaining that does not work, break out your trusty magnifying glass and
show them a secret solar power demo on their skin….and blame it on the server
admins…
Jimmy Ray
