Bournemouth — Jun 17th 2014

John Ansell presented a short history of his experiences with electricity monitors some of which he produced out of his bag as he proceeded with his presentation. About five years ago he bought an energy monitor from E-on, his energy company. He showed how the sensor part clips to the main electricity input to the house while the display part, connected wirelessly, shows the instantaneous energy usage. This allows consumers (that’s us), in theory, to adjust their behaviour to reduce consumption. It took John some time and work to connect it to his Mac to capture the data: configuration in Terminal to connect, a PERL script to manipulate the data and create a CSV document to load finally into a spreadsheet.

John found the device interesting but did not feel that he actually reduced his consumption. As an aside, he clarified what these monitors actually measure. A kW (kilowatt) is the unit used to express the consumption of power (including electricity); a one bar electric heater consumes 1kW. The meters measure in kWh (kilowatt hour), a unit equivalent to using one kilowatt of power for one hour (eg leaving the heater on for an hour). Energy companies (in electricity bills) charge by the kWh.

E-on later gave John a newer and cheaper (free!) monitor. This joins his home network (via an Ethernet cable) and automatically uploads its data to a supplier (Current Cost) operated server. This generates graphs that can be viewed in a web browser. In a classic case of demo-itis, the server decided to use the day of the meeting to develop a fault so John could not show us any ‘live’ graphs so he showed some data from previous days.

John also uses a monitor to measure the generation of electricity by his solar panels. This has the promise of saving money by juggling consumption (eg when to run the washing machine) to match the availability of ‘free’ solar power (that cannot be stored so is given away if not used).
Finally, there was a discussion of Smart Meters that are being rolled-out nationally by 2020. This promises to give us all a display of consumption along with more accurate bills.

The presentation was followed by the customary questions and answers session:
a problem with Airplay of a DVD playing on Mac via an Apple TV to a TV was possibly due to Apple’s DVD Player program respecting content protection. VLC might work instead?
a Pages document was apparently complaining that it needed a newer version of Pages than the current latest! It seems likely that it had become associated with the old version of Pages and that this could be changed via the Finder’s Get Info dialogue box.

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