Archive for October, 2009

Wireless Electricity Meters

October 31, 2009

 

Efergy Wireless Electricity meter

Efergy Wireless Electricity meter

I am a big fan of wireless electricity meters – they make electricity consumption visible. And if you are trying to reduce your electricity consumption they are a fantastic tool. I bought one of these units a couple of years ago but it had no memory. So earlier this year I overcame my reluctance to buy another piece of consumer nonsense and bought this Efergy unit. It keeps track of the last 7 days energy consumption in memory and so I can plot a graph showing the household electricity consumption day by day.

 

My Electricity Consumption for 2009

My Electricity Consumption for 2009

The graph is remarkably dull. The 7 day average plummets when we go away (but why only to 5 units a day is a mystery to me) and we have weekly peaks in consumption when we do washing and tumble drying. Surprisingly I haven’t seen much evidence of a dependence on day length yet, but I expect that will begin to show up soon. However despite their usefulness for plotting variations in electricity consumption, the thing I wanted to highlight was the poor accuracy of the units.

As I write my Electrisave meter says I am currently using 0.6 kW while my Efergy meter says I am using 0.55 kW. This 10% discrepancy is typical, and not always in the same direction. In fact this is within specification for the units which only claim 10% accuracy. Because it has memory, I can test the performance of the Efergy unit against the EDF energy meter that determines how much I pay. Since July when I began the comparison, the Efergy unit under-reads by between 15% and 25% depending on exactly which period I compare them. I think this is because the units’ sensors read only the electrical current and the energy consumption depends on the relative phase of teh current and voltage. For households using lots of low energy light bulbs (for instance) the phase can vary significantly. I don’t think this really detracts from the utility of these devices – but it is perhaps worth bearing in mind.

 

 

 

You can’t believe what you read in the papers!

October 11, 2009
Weeping Bunny

Weeping Bunny

Never again will I believe >ANYTHING< I read in The Independent. I feel like a fool. And my feeling of foolishness must be mirrored by others who reflect that that they will never believe another story about Climate Change no matter where they read it.

I refer to the story I highlighted in the Independent as being unusually perceptive: their calling attention to the opening up of the North East passage from the far east to Europe through the Arctic Ocean over the top of Russia. The same story was covered in another of my least favourite newspapers: The Times. However reading the Register the other day I found Andrew Orlowski revelling in fact the newspapers had simply regurgitated a press release from a shipping company rather than doing some research. They do not even appeared to have looked up Wikipedia which must count as some kind of journalistic nadir.

I hate Andrew Orlowski’s style of writing and I hate the glee with which he debunks the mythology of the Climate Change movement. But in this case, he is right to do so. And he is also right to mock the ‘scare the children‘ adverts that are being pedalled by the government.

The truth – and that is probably what both Andrew Orlowski & I would agree is a desirable thing to know – the truth is this: we just don’t know what is going to happen to the Climate. For example, no Climate model predicted roughly stable Global Mean Temperature for the last 10 years. Its just a fact. But that doesn’t mean there is nothing to be concerned about: there is. Because to the best of our knowledge – limited as that is – we expect climates to change around the world over the next decades. Mostly for the worse. However, the newspaper stories based on nonsense; the association of each bad weather event with climate change; and the cheap propaganda from the government: these do us all a disservice.


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