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The case for "smart" surge protectors

I've been seeing magazine and newsletter articles for some time promoting the new "smart" surge protector that shut off power to peripheral devices when a "master" device is turned off, but I figured we didn't need one because we usually turn off our power strips manually.  In practice, though, we often weren't turning off the one in the living room, because we'd turn off the TV with the remote and then walk away, go to bed, etc.  So I decided to pick up a Philips model (right) for $20 at Wal-Mart and see what the Kill A Watt meter could tell me about it. Here's what I found.

First, the setup.  Our fluorescent-backlit, LCD TV is plugged into the Master plug, and our Blu-Ray player, VCR, and Wii are plugged into three of the Secondary plugs.  When we had a cable box, it was on the Bypass plug (which doesn't turn off), but we returned the cable box today.  I plugged the surge protector into the Kill A Watt, which in turn was plugged into the wall.

In the table below, I distinguish between "standby" and "sleep" -- the former meaning the device hasn't been turned on yet, the latter meaning it's been turned "off" but is still consuming more power than it did before it was on -- because these values are different for the Blu-Ray player and Wii.  The VCR uses the same amount of power before and after being turned on, so I don't make that distinction for it.

TV Blu-Ray VCR Wii power drawn (Watts)
standby off off off 1 W
on (50% brightness) unplugged unplugged unplugged 100 W
on standby standby standby 114 W
on playing standby standby 131 W
on sleep standby standby 115 W
on sleep on standby 115 W
on sleep standby playing 129 W
on sleep standby sleep 122 W

So here's what I learned:

  • The surge protector does not contribute measurably to the power drawn.  (The TV by itself draws a little less than 1 Watt on standby.)
  • The Blu-Ray player draws 1 more Watt after it's turned "off" than before it's turned on.
  • The Wii draws 7 more Watts after it's turned "off" than before it's turned on.  (Nintendo is the least "green" electronics company, according to Greenpeace.)
  • If we don't use any of the peripherals and then turn off the TV, the surge protector saves us 14 watts, or about $15.22 per year compared to leaving them on standby.
  • If we do use the devices and then turn off the TV, the surge protector saves us 22 Watts, or about $23.91 per year compared to leaving them asleep.

So given that we were lax about turning off the old power strip, this surge protector will pay for itself in a little over a year.  Your mileage may vary!


For ease of our varying mileage, would you mind disclosing your electric rate that you used to calculate your savings?Thanks for the review.  I've been considering one of these for exactly the same place and reasons.

According to row 6 in your table, the VCR draws the same amount of power whether on or off.  Is this correct? 

Yes, that's correct.  I didn't test it while playing a tape, though, since it can't be left playing indefinitely like the two other devices.

I picked up a power strip with a timer the other day.  I want to say it is a Phillips, though it might be GE.  Interestingly it is not a surge protector, and the timer is powered by button cell batteries rather than just the plug.  It is a reasonable but not great timer in terms of design features.  The strip itself has 4 timer controlled and 4 uncontrolled outlets that are tamper-resistant for those with kids, but not well laid out for power bricks, which seems dumb given the likelyhood that those are exactly what would be plugged into it.  We're now using it to turn off our cable modem, router and printer when we're not around or awake to use them.  As I haven't invested in a Kill a watt, I have no idea how long it will take to pay for its ~$20 price tag.Along that vein, Ben, perhaps I've mentioned this before, but what do you think about encouraging libraries to buy kill a watts that people could check out to use?

Well, based on my own measurements, your router and cable modem were likely costing you a little over $3/year each, so depending on how much power your printer uses and how often the battery has to be replaced, the timer could pay for itself in two years, but four or five would be more likely.

I'm in favor of libraries offering tools for checkout in general -- the library in Fairfield, IA does more of that than any other library I've known -- but I have no experience in encouraging libraries to start offering things they don't currently carry.  I do think electric utilities should offer equipment like the Kill A Watt for rent or loan.

Our utility has a promotion on where you can get a "smart" thermostat for free... not only is it programmable, it's remotely programmable over the Internet, by you or by them.  It kind of gives me the creeps, actually.  I don't know how people have taken them up on that offer!

Batteries -- especially non-rechargeable batteries such as alkalines -- are extremely expensive when measured in dollars per watt-hour.  This is why I am opposed to having items around the house that run on AA, AAA, C, or D cells unless there's a good reason, such as portability.  In particular, I will not put in a battery-powered wall thermostat for controlling the household heating.  Our furnace already has a 24V transformer which energizes the gas valve when the bimetal thermostat (Honeywell's "The Round") calls for heat.  The modern thermostats contain a microcomputer that maintains a schedule of temperature set points.  The batteries power the micro and also retain the set point memory even if there is a temporary loss of electrical service to the home.  But with today's technology, the set points could be stored in flash ROM and the thermostat unit could be powered from the 24V transformer, eliminating the need for batteries.  So, I'd suggest that you consider items that use disposable batteries to be generally uneconomical and undesirable.

So, I'd suggest that you consider items that use disposable batteries to be generally uneconomical and undesirable.

How much power does a battery have to save before it justifies its existence?  I agree, in most applications I'd rather see a rechargeable battery (or a battery shape such that a rechargeable can be substituted) than a disposable one, and AC power when feasible.  Now that flash memory is so cheap, a manufacturer has to be really lazy to use a battery to keep the memory alive.  But even so, when the $2 battery in Nathaniel's timer can save him $12 or more over its 3-year lifetime, cost is not reason enough to avoid buying the device.  The AA batteries in a programmable thermostat (which can easily have rechargeables substituted for the disposables that are included) can easily pay for themselves and the thermostat in the first year and save you a hundred or more cold walks down the hall. 

If you like waking up before dawn to turn up the heat or turning off power strips manually when you leave the house, that's great; there may be a valid philosophical argument for avoiding batteries, but the cost argument does not hold up.

The cost goes beyond the batteries themselves.  Over the years, leaky carbon-zinc batteries have ruined my flashlights, cameras, remote controls, wireless mikes, etc.  The only way to avoid this is to replace the batteries on a regular schedule *while they are still good*.  Rechargeables are not the solution.  Who wants to spend his time constantly shifting batteries from devices to rechargers and then back again?  I've also experienced a rechargeable battery bursting while on the charger. Incidentally, mercury cells typically do not leak, but I have seen it happen.  Another thing: inquire carefully before you trust a battery recycler.  Our Radio Shack store puts old batteries into the regular trash!

We are way off topic, Dad, but I'll address your question:

Rechargeables are not the solution.  Who wants to spend his time constantly shifting batteries from devices to rechargers and then back again?

We have all rechargeable batteries here.  The solar-recharging devices (Christmas lights) are the only ones using NiCd; everything else uses either NiMH or ordinary disposable alkaline (not "heavy duty" carbon-zinc) batteries, which I recharge with a charger designed and marketed for that purpose.  (It also does other rechargeables.) Disposable alkalines don't recharge as well or as many times as NiMH, and they have to be checked for leakage after recharging since they aren't always up to the strain, but they are significantly cheaper and easier to find in a variety of sizes (including 9V and D cells), and they tend to come included with new devices, such that recharging them is preferable to throwing them away after one use.

In Kansas, NiMH and alkaline batteries are not considered hazardous waste, so as far as I know everyone in Emporia (not just Radio Shack) puts them in the regular trash.  NiCd, lithium, and mercury batteries are considered hazardous waste and as far as I know are disposed of properly by both Radio Shack and Staples as well as the city-operated hazardous waste drop-off site.

We've only had one alkaline battery leak in a device, and that was because we (I) missed the warning signs when it came out of the charger.  I have never, in more than 10 years of using NiCd and NiMH rechargeables, had one leak in a device or explode in a charger.  So the leakage argument is a good argument against carbon-zinc "heavy-duty" batteries, not against rechargeables.

But back to the question.  Jessie generally lets me change the batteries, so I have a good handle on how much time we spend doing it.  I would wager that I change one set of batteries about once in two weeks, on average.  I've definitely gone for a month or more without changing any, and other times had to change several within an hour (for example, if we go for weeks without using the Wii). It takes about one minute to remove a pair of batteries, put them in the charger, and replace them with a fresh pair.  If I do that every two weeks, that's 26 minutes of my time per year.

I previously estimated with the Kill A Watt meter that the battery charger uses about 20 Wh to charge a pair of batteries, or about $0.91 per year.  (This estimate was assuming a lot more than 26 charges a year, but let's run with it.)  It's a safe bet that we don't get all 20 Wh back out of a pair of batteries when we use them.  But even assuming that we're wasting most of the power, say $0.75 per year, does that count as "extremely expensive when measured in dollars per watt-hour"?

I see where this argument has come from: the smart surge protector I talked about above saves us the trouble of switching off a power strip, and we were probably spending less than 26 minutes a year doing that before, so if our time is so precious, surely we should object to recharging batteries as well.  But we were wasting a lot more than $0.91 by not switching off the power strip.

If we had a policy of not using household batteries, the Wii would be out of the picture; we would have had to buy a different bed; we'd have had to have our attic rewired in order to have smoke and CO alarms wired into house current; and we'd watch a lot less television because we wouldn't be able to use the DVD player at all and walking across the room to change channels or adjust the volume would waste far more than 26 minutes a year.  All of those (except the bed) could arguably be improvements in our lifestyle.  If living a more monastic, pastoral lifestyle were our goal, a ban on batteries would help get us there.  But our goal is to reduce our environmental impact while keeping a lifestyle we like, and for better or worse, batteries are a part of that.  We find rechargeables (including alkalines) to be an economical and convenient compromise. 

I'm sorry that you've had bad luck with rechargeables; I remember you also had reliability problems with compact fluorescent light bulbs for many years, while others of us had far less trouble with the same devices.  Have you checked the house current?

Off topic is not always a bad thing.  I have to agree that if I can avoid having something be battery powered I'm for it, but as you point out Ben, there are lots of things that just need batteries.  The powerstrip I got was not one of them.  Maybe a battery backup, but as you've said, flashrom would have accomplished that.More importantly.  What is this battery charger that will recharge regular batteries fairly safely and where do I get one?  We've discovered that having a baby has exponentially increased our battery needs.

Here's the charger we have, Nathaniel: