Skip to content
September 1, 2009 / Jim Fenton

Energy WHAT?!

We were moving some furniture this past weekend, and I was moving the satellite receiver in the bedroom when I came upon this:

EnergyStarlet

That’s right, it’s the satellite receiver I wrote about a couple of weeks ago, the one that takes 11 watts turned on and 10 watts turned “off”, and it has an Energy Star sticker on top.  But I associate Energy Star with computer monitors (especially the older CRTs) that turn themselves almost completely off when not in use.  How is this possible?

I went to the Energy Star website to research the criteria for set-top boxes to be listed as Energy Star compliant.  According to the page on set-top boxes for consumers:

Set-top boxes that have earned the ENERGY STAR are at least 30 percent more efficient than conventional models.

I’m not at all sure what a “conventional model” is.  Presumably there are satellite receivers that are even worse, but DirecTV offers a very limited choice sso I’m not sure you can actually get one.  So I went on to the information for “partners” (equipment manufacturers).  The program requirements list a number of different types of set-top boxes (such as cable, satellite, IP, terrestrial), along with optional capabilities (additional tuners, advanced video processing, DVR, and so forth).  Limits are given in kWh/year for each type of set-top box, with additional allowances for each additional capability present.  There are two tiers of limits: Tier 1, effective January 1, 2009, and Tier 2, effective January 1, 2011.

The Tier 1 limit for a satellite set-top box with no additional capabilities is 88 kWh/year.  But what bothers me is how that’s calculated:

kWhBase = 0.365 * (14 * Ptv + 10 * Psleep)

In other words, the formula assumes that the receiver is on 14 hours a day.  While some people must use their TVs that much, it’s hard to believe that this is typical, even in the US.  The result is that Psleep (the power consumption when turned “off”, more accurately characterized as sleep mode) does not count for as much as it should.

Under this formula, my set-top box consumes 93 kWh/year.  This doesn’t qualify under the current limits, but it’s very possible that they were different in 2004 when it was built. The criteria continue to tighten; the Tier 2 limit, effective 2011, is 55 kWh, a step in the right direction.  But they need to rethink the duty cycle in the test criteria, as well as whether these are actually 30% more efficient than anything, as claimed on the consumer Energy Star website.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s