Five Percent: Conserve Energy

Climate Change Is Important: Energy Conservation is the First Step

March 28, 2009

The Last 200W Identified During Earth Hour

Category: Save Electricity,Take Actions – Tom Harrison – 10:42 pm

0.0 kW by Candle Light

0.0 kW by Candle Light

Earth Hour is over. Across the world, people switched off lights, in a symbolic gesture. We did, too.

Last year, we hit the main breaker in the house and enjoyed the silence and darkness. This year, we tried something a little different.

This year we searched, and found the 200 Watts that our house uses every hour of every day, even when it’s night and all the lights, fridge, dishwasher, dryer and anything we are actually using is off.

If you have followed my blog, you’ll know that we have rather effectively reduced our electricity usage — less than 1/2 what we used a couple years ago. After making all of the obvious changes, and some of the less obvious ones, we had made some great progress.

Then, last summer, we bought a PowerCost Meter, which gives you a real-time readout of your electrical use. We found a lot of other small culprits. In the end, we are regularly able to go to bed using a mere 200 Watts.

But 200 Watts of … what?

So tonight instead of flipping the power main, we started unplugging things. We looked for the tell-tale red or green indicator lights on the numerous electronic things we have in the house. Computer speakers, monitors, TVs, clocks, a carbon-monoxide monitor, cable modem, battery charger, cell phone chargers, router, power strips, and wireless phones.

One by one we unplugged them, then walked around the house looking … and listening. The aquarium filter made noise, and we unplugged it. A computer that wasn’t on standby was whirring, and we shut it down. Then the fridge turned on — it sounded like a freight train (well, a quiet freight train). And the last sound we heard was the TiVo — barely audible; off it went.

And yes, except for the stove and dishwasher, we unplugged everything that had any light on it. And, for the first time, we saw our power monitor read 0.0 — here’s a picture taken by candle-light.

But as we turned things on again, we learned what really uses those 200 Watts. The TiVo uses about 45 Watts. Four phones, and a carbon monoxide monitor with their cheap vampire transformers all used another 65 Watts! The router uses 12 Watts, and the cable modem uses 6 Watts. The rechargeable battery charger uses 2 watts. The aquarium filter and a few other small things (clocks, cell chargers, toaster) added up to about 10 Watts. The last two things really surprised me: the speakers on three computers combined, use 45 watts! More cheap electronics that have absolutely no purpose when the computer is off. In the end only a small amount is actually needed for anything but a fraction of each day.

And very little of it should be needed. First, the TiVo is always on — this is a device that maintains a schedule of what you want it to record — one would think it could go into a very low-power mode, just enough to wake up when the clock (or something on the network) said so, but it just records all the time. And in case you’re thinking you’re so clever, your cable or satellite box, if you have one almost certainly draws two to three times as much power as the TiVo (I used to have one, and mine used 130 Watts). Still, the TiVo is a great thing, and it’s relatively frugal.

None of the devices using transformer blocks, or the speakers, should be drawing any power. The old blocks get warm to the touch, and are completely replaceable with a “switch mode” transformer that does exactly the same function using only a tiny bit of power (much less than 1 watt) when there’s no power flowing.

I hadn’t gotten around to buying “Smart Strip” power strips for the three or four locations in the house that could use them. These devices are good for setups like computers and TVs — when the main thing is off, the smart strip turns off the power to the auxiliary devices (computer speakers, monitors, game consoles, etc.) that aren’t needed. I think with three of these, I can save something like 100 – 120 more watts of standby power.

So if I can stop wasting 100 Watts every hour of every day, at the $0.22/kWh rate we’re charged for electricity, I’ll save almost $200/year. (100W = .1kW, so for 24 hours that’s 2.4kWh per day, 365 days per year is 876 kWh * $0.22 = $192.72. This will save us more than one month of total electrical use at our current rate. In other words, saving just 100 Watts that was otherwise used all the time, will reduce our electricity bill by a little more than 10%.

The Smart Strips run from $25 to $50 — Amazon had a sale, and I just got three of the fancy ones for $78, with free shipping. They’ll be paid for in less than 6 months.

But wait, let’s get back to what’s important here. Sure, our electricity bill is small. But even after several years of doing this stuff, in one hour, we found another way to stop using electricity we don’t use. This is power that does absolutely nothing for us.


  1. that’s an impressive piece of detective work. I’m glad the aquarium doesn’t use much, I’d hate to think people would have a motive to not keep fish.

    I don’t have a Tivo, but I gather it runs Linux. If someone hasn’t worked out a hack to reduce it’s power consumption already then it’s probably only a matter of time. Maybe you will yet manage to squeeze a few more watts out of it!

    Comment by Tony Wildish — March 29, 2009 @ 5:44 am

  2. Yeah, the original TiVos were just PCs running Linux, and the user interface was written in TCL. It was easy to log in as the root user and pretty much do whatever you wanted. I think it’s a little more “locked down” in the latest HD versions. I am on the beta-testing TiVo list (along with thousands of others), but I try to make my voice heard whenever they ask. It’s such an obvious thing for them to let the user decide — all the bits for putting the device into low-power mode as there, it’s just a matter of deciding to use them.

    Comment by Tom Harrison — March 29, 2009 @ 10:38 am

  3. Here’s a nice photo montage from (which doesn’t really represent Boston that well). Wait for the images to load, then click them to see the before and after.

    Comment by Tom Harrison — March 30, 2009 @ 6:27 pm

  4. […] my favorite comment about why we need a climate change law now and send a free Blue Line Powercost Monitor (used) — this is the one I have been using for almost a year now, and have written about […]

    Pingback by A Simple Call You Can Make To Support Climate Change Legislation | Five Percent: Conserve Energy — December 4, 2010 @ 10:34 pm

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