From 5 kilowatts to 5 watts

I was in Bletchley Park last week for the Over the Air event. One of the highlights was a tour of the museum in which we got to see a reconstruction of the first computer the Colossus. Originally the computers were left on all day but now they are only switched on from time to time for tours due to the high cost of running them (and for environmental reasons).

Colossus computer at Bletchley Park

Colossus computer at Bletchley Park

The machines use a whopping 5.5 kilowatts of electricity and standing near them you can certainly feel the heat. The sheds in which they are kept apparently get pretty warm in winter too.

iPhone charging

iPhone charging

My iPhone by comparison uses only  5 watts (approximately)  or 0.1% of the power usage of the Colossus!

The increasing energy efficiency of computers is formalised in Koomey’s law which states that “at a fixed computing load, the amount of battery you need will fall by a factor of two every year and a half”. This trend has all sorts of interesting implications as it will allow computer to become smaller and more ubiquitous in the future.

Plotting Xively timeseries data using Rickshaw

Xively (formerly Cosm, formerly Patchube) now has a Javascript library for their API. I have been meaning to learn the Rickshaw library for awhile as it comes highly recommend from several people. It turned out to be a doddle to use. I just mixed in the moment.js library to do some date munging and was able to knock up some graphs in an hour or so.

Air Quality Egg

AirQualityEgg NO2 data

AirQualityEgg NO2 data

Current cost electricity usage

 

Current cost electricity data

Current cost electricity data

These two data source aren’t pumping out data anymore but you can see an example here.

 

The code

The code is also on github.